序列化

作者: 南园故剑00 | 来源:发表于2020-06-12 11:24 被阅读0次

1. 序列化的意义

含义

序列化是把对象的状态信息转化为可存储或者传输的形式的过程，也就是把对象转化为字节序列的过程称为对象的序列化。
反序列化是把字节序列恢复为对象的过程称为对象的反序列化

序列化就是把实体对象状态按照一定的格式写入到有序字节流，反序列化就是从有序字节流重建对象，恢复对象状态

意义

（1）永久性保存对象，保存对象的字节序列到本地文件或者数据库中；

（2）通过序列化以字节流的形式使对象在网络中进行传递和接收；

（3）通过序列化在进程间传递对象；

序列化算法一般会按步骤做如下事情

（1）将对象实例相关的类元数据输出。

（2）递归地输出类的超类描述直到不再有超类。

（3）类元数据完了以后，开始从最顶层的超类开始输出对象实例的实际数据值。

（4）从上至下递归输出实例的数据

2. 优劣指标：

序列化后的数据大小
序列化操作本省的速度以及系统资源开销：CPU、内存

3. JDK的序列化：

3.1 一个类只要实现了 java.io.Serializable 接口，那就可以被序列化

/**
 * @description:
 * @date : 2020/1/7 22:56
 * @author: zwz
 */
public interface ISerializer {

    <T> byte[] serializer(T obj);

    <T> T deSerializer(byte[] data, Class<T> clazz);
}

3.2 通过输出流 java.io.ObjectOutputStream 和对象输入流 java.io.ObjectInputStream 来实现

package com.gp.lock.serizlizer;

import java.io.*;

/**
 * @description: 基于JDK实现序列化
 * @date : 2020/1/7 22:58
 * @author: zwz
 */
public class JavaSerializer implements ISerializer {

    /**
     * 序列化
     * 使用输出流
     * @param obj
     * @param <T>
     * @return
     */
    public <T> byte[] serializer(T obj) {
        ByteArrayOutputStream byteArrayOutputStream = null;
        ObjectOutputStream objectOutputStream = null;
        try {
            byteArrayOutputStream = new ByteArrayOutputStream();
            objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);
            objectOutputStream.writeObject(obj);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (objectOutputStream != null) {
                    objectOutputStream.close();
                }
                if (byteArrayOutputStream != null) {
                    byteArrayOutputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return byteArrayOutputStream.toByteArray();
    }

    /**
     * 反序列化
     * 使用输入流
     * @param data
     * @param clazz
     * @param <T>
     * @return
     */
    public <T> T deSerializer(byte[] data, Class<T> clazz) {
        ByteArrayInputStream byteArrayInputStream = null;
        ObjectInputStream objectInputStream = null;
        Object result = null;

        try {
            byteArrayInputStream = new ByteArrayInputStream(data);
            objectInputStream = new ObjectInputStream(byteArrayInputStream);
            result = objectInputStream.readObject();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                if (byteArrayInputStream != null) {
                    byteArrayInputStream.close();
                }
                if (objectInputStream != null) {
                    objectInputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        return (T) result;
    }
}

3.3 实例

package com.gp.lock.serizlizer;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Arrays;

/**
 * @description:
 * @date : 2020/1/7 23:11
 * @author: zwz
 */
public class User /*extends SuperClass*/ implements Serializable {

    private static final long serialVersionUID = 6322539910270175988L;

    public static int num = 5;

    private String name;

    private int age;

    private transient String hobby;

    public String getHobby() {
        return hobby;
    }

    public void setHobby(String hobby) {
        this.hobby = hobby;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public static int getNum() {
        return num;
    }

    public static void setNum(int num) {
        User.num = num;
    }

    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", hobby='" + hobby + '\'' +
                '}';
    }

    private void writeObject(ObjectOutputStream outputStream) throws IOException {
        outputStream.defaultWriteObject();
        outputStream.writeObject(hobby);
    }

    private void readObject(ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
        inputStream.defaultReadObject();
        hobby = (String) inputStream.readObject();
    }

    public static void main(String[] args) {
        ISerializer serializer = new JavaSerializer();
        User user = new User();
        user.setAge(18);
        user.setName("mic");

        byte[] bytes = serializer.serializer(user);
        System.out.println(Arrays.toString(bytes));

        User deSerializer = serializer.deSerializer(bytes, User.class);
        System.out.println(deSerializer);
    }
}

4. 高阶认识

4.1 serialVersionUID 的作用

Java的序列化机制是通过判断类的 serialVersionUID 来验证版本一致性的。
在进行反序列化时，JVM会把传来的字节流中的serialVersionUID与本地相应实体的serialVersionUID进行比较，如果相同就认为时一致的，可以进行反序列化，否则就会出现序列化版本不一致的异常，即是 InvalidCastException。
如果没有为指定的 class 配置 serialVersionUID，那么 java 编译器会自动给这个 class 进行一个摘要算法，类似于指纹算法，只要这个文件有任何改动，得到的 UID 就会截然不同的，可以保证在这么多类中，这个编号是唯一的

4.2 静态变量序列化

序列化保存的是对象的状态，静态变量属于类的状态，因此序列化并不保存静态变量。

4.3 父类的序列化

当一个父类没有实现序列化时，子类继承该父类并且实现了序列化。在反序列化该子类后，是没办法获取到父类的属性的。
当一个父类实现序列化，子类自动实现序列化，不需要再显示实现Serializable 接口
当一个对象的实例变量引用了其他对象，序列化该对象时也会把引用对象进行序列化，但是前提是该引用对象必须实现序列化接口

4.4 Transient

Transient 关键字的作用是控制变量的序列化，在变量声明前加上该关键字，可以阻止该变量被序列化到文件中
在被反序列化后，transient 变量的值被设为初始值，如 int 型的是 0，对象型的是 null

5. 序列化实现深拷贝

浅克隆：被复制对象的所有变量都含有与原来的对象相同的值，而所有的对其他对象的引用仍然指向原来的对象
深克隆：

被复制对象的所有变量都含有与原来的对象相同的值，除去那些引用其他对象的值。
那些引用其他对象的变量将指向被复制过的新对象，而不再是原有的哪些被引用的对象。
深拷贝把要复制的对象所引用的对象都复制了一遍。

package com.zwz.serializer;

import java.io.*;

/**
 * @description: 实现深克隆效果
 * 把对象序列化输出到一个流中，然后对象序列化流中读取出来，这个对象就不是原来的对象了。
 * @date : 2020/1/8 15:23
 * @author: zwz
 */
public class Person implements Cloneable, Serializable {

    private static final long serialVersionUID = 5532843697249498959L;

    private String name;

    private Email email;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Email getEmail() {
        return email;
    }

    public void setEmail(Email email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", email=" + email.getContent() +
                '}';
    }

    @Override
    protected Person clone() throws CloneNotSupportedException {
        return (Person) super.clone();
    }

    public Person deepClone() throws IOException, ClassNotFoundException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);
        objectOutputStream.writeObject(this);

        byte[] data = byteArrayOutputStream.toByteArray();

        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(data);
        ObjectInputStream objectInputStream = new ObjectInputStream(byteArrayInputStream);
        Object object = objectInputStream.readObject();
        return (Person) object;
    }

    public static void main(String[] args) throws CloneNotSupportedException, IOException, ClassNotFoundException {
        Email email = new Email();
        email.setContent("8:00");

        Person person = new Person();
        person.setName("mic");
        person.setEmail(email);

        Person person1 = person.deepClone();
        person1.setName("mak");
        person1.getEmail().setContent("9:00");

        System.out.println(person.getName() + "->" + person.getEmail().getContent());
        System.out.println(person1.getName() + "->" + person1.getEmail().getContent());

        System.out.println("-------------");

        Person person2 = person.clone();
        person2.setName("mac");
        person2.getEmail().setContent("10:00");

        System.out.println(person.getName() + "->" + person.getEmail().getContent());
        System.out.println(person1.getName() + "->" + person1.getEmail().getContent());
        System.out.println(person2.getName() + "->" + person2.getEmail().getContent());
    }

    /**
     * @description:
     * @date : 2020/1/8 15:21
     * @author: zwz
     */
    public static class Email implements Serializable {

        private static final long serialVersionUID = -2800552551799395733L;

        public Email(String content) {
            this.content = content;
        }

        private String content;

        public Email() {

        }

        public String getContent() {
            return content;
        }

        public void setContent(String content) {
            this.content = content;
        }
    }
}

6. 常见的序列化技术

6.1 使用 JAVA 进行序列化有他的优点，也有他的缺点

优点：JAVA 语言本身提供，使用比较方便和简单
缺点：不支持跨语言处理、性能相对不是很好，序列化以后产生的数据相对较大

6.2 XML 序列化框架

XML 序列化的好处在于可读性好，方便阅读和调试。
但是序列化以后的字节码文件比较大，而且效率不高。
适用于对性能不高，而且 QPS 较低的企业级内部系统之间的数据交换的场景。
同时 XML 又具有语言无关性，所以还可以用于异构系统之间的数据交换和协议。
Webservice采用 XML 格式对数据进行序列化的

package com.gp.lock.serizlizer;

import com.thoughtworks.xstream.XStream;
import com.thoughtworks.xstream.io.xml.DomDriver;

/**
 * @description:
 * @date : 2020/1/8 15:54
 * @author: zwz
 */
public class XmlSerializer implements ISerializer {

    XStream xStream = new XStream(new DomDriver());

    public <T> byte[] serializer(T obj) {
        return xStream.toXML(obj).getBytes();
    }

    public <T> T deSerializer(byte[] data, Class<T> clazz) {
        return (T) xStream.fromXML(new String(data));
    }
}

6.3 JSON 序列化

JSON（JavaScript Object Notation）是一种轻量级的数据交换格式，相对于 XML 来说，JSON 的字节流更小，而且可读性也非常好。
现在 JSON数据格式在企业运用是最普遍的。JSON 序列化常用的开源工具有很多
1. Jackson （https://github.com/FasterXML/jackson）
2. 阿里开源的 FastJson （https://github.com/alibaba/fastjon）
3. Google 的 GSON (https://github.com/google/gson)
这几种 json 序列化工具中，Jackson 与 fastjson 要比 GSON 的性能要好，但是 Jackson、GSON 的稳定性要比 Fastjson 好。
而 fastjson 的优势在于提供的 api 非常容易使用

package com.gp.lock.serizlizer;

import com.alibaba.fastjson.JSON;

/**
 * @description:
 * @date : 2020/1/8 16:12
 * @author: zwz
 */
public class FastJsonSerializer implements ISerializer {

    public <T> byte[] serializer(T obj) {
        return JSON.toJSONString(obj).getBytes();
    }

    public <T> T deSerializer(byte[] data, Class<T> clazz) {
        return JSON.parseObject(new String(data), clazz);
    }
}

6.4 Hessian 序列化框架

Hessian 是一个支持跨语言传输的二进制序列化协议，相对于 Java 默认的序列化机制来说，Hessian 具有更好的性能和易用性，而且支持多种不同的语言
Dubbo 采用的就是 Hessian 序列化来实现，只不过 Dubbo 对Hessian 进行了重构，性能更高

7. Protobuf（Protocol Buffer）序列化框架

7.1 简介

Protobuf 是 Google 的一种数据交换格式，它独立于语言、独立于平台。
Google 提供了多种语言来实现，比如 Java、C、Go、Python，每一种实现都包含了相应语言的编译器和库文件。
Protobuf 使用比较广泛，主要是空间开销小和性能比较好，非常适合用于公司内部对性能要求高的 RPC 调用。
由于解析性能比较高，序列化以后数据量相对较少，所以也可以应用在对象的持久化场景中
但是要使用 Protobuf 会相对来说麻烦些，因为他有自己的语法，有自己的编译器

7.2 使用实例

到官网下载protobuf的相应版本，我这里下载的是windows下的3.1.0版protoc-3.1.0-win32.zip
将下载好的zip解压，能看到bin目录下有一个protoc.exe的文件，等下需要用它来编译文件，我们直接在bin目录下创建一个简单的person.proto的描述文件

syntax = "proto3";

option java_package = "com.gp.lock.serizlizer.protobuf";
option java_outer_classname = "PersonFactory";

message Person{

     int32 id = 1;
     string name = 2;
     int32 age = 3;
     Addr addr = 4;
   
}

message Addr{
     
     string contry = 1;
     string city = 2;

}

使用protoc编译上述.proto文件，生成Java类，使用如下命令完成该操作:protoc --java_out=./ ./person.proto
将PersonFactory.java文件引入到我们的项目中，并引入对应版本的protobuf的依赖包

// Generated by the protocol buffer compiler.  DO NOT EDIT!
// source: person.proto

package com.gp.lock.serizlizer.protobuf;

public final class PersonFactory {
    private PersonFactory() {
    }

    public static void registerAllExtensions(
            com.google.protobuf.ExtensionRegistryLite registry) {
    }

    public static void registerAllExtensions(
            com.google.protobuf.ExtensionRegistry registry) {
        registerAllExtensions(
                (com.google.protobuf.ExtensionRegistryLite) registry);
    }

    public interface PersonOrBuilder extends
            // @@protoc_insertion_point(interface_extends:Person)
            com.google.protobuf.MessageOrBuilder {

        /**
         * <code>optional int32 id = 1;</code>
         */
        int getId();

        /**
         * <code>optional string name = 2;</code>
         */
        String getName();

        /**
         * <code>optional string name = 2;</code>
         */
        com.google.protobuf.ByteString
        getNameBytes();

        /**
         * <code>optional int32 age = 3;</code>
         */
        int getAge();

        /**
         * <code>optional .Addr addr = 4;</code>
         */
        boolean hasAddr();

        /**
         * <code>optional .Addr addr = 4;</code>
         */
        Addr getAddr();

        /**
         * <code>optional .Addr addr = 4;</code>
         */
        AddrOrBuilder getAddrOrBuilder();
    }

    /**
     * Protobuf type {@code Person}
     */
    public static final class Person extends
            com.google.protobuf.GeneratedMessageV3 implements
            // @@protoc_insertion_point(message_implements:Person)
            PersonOrBuilder {
        // Use Person.newBuilder() to construct.
        private Person(com.google.protobuf.GeneratedMessageV3.Builder<?> builder) {
            super(builder);
        }

        private Person() {
            id_ = 0;
            name_ = "";
            age_ = 0;
        }

        @Override
        public final com.google.protobuf.UnknownFieldSet
        getUnknownFields() {
            return com.google.protobuf.UnknownFieldSet.getDefaultInstance();
        }

        private Person(
                com.google.protobuf.CodedInputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws com.google.protobuf.InvalidProtocolBufferException {
            this();
            int mutable_bitField0_ = 0;
            try {
                boolean done = false;
                while (!done) {
                    int tag = input.readTag();
                    switch (tag) {
                        case 0:
                            done = true;
                            break;
                        default: {
                            if (!input.skipField(tag)) {
                                done = true;
                            }
                            break;
                        }
                        case 8: {

                            id_ = input.readInt32();
                            break;
                        }
                        case 18: {
                            String s = input.readStringRequireUtf8();

                            name_ = s;
                            break;
                        }
                        case 24: {

                            age_ = input.readInt32();
                            break;
                        }
                        case 34: {
                            Addr.Builder subBuilder = null;
                            if (addr_ != null) {
                                subBuilder = addr_.toBuilder();
                            }
                            addr_ = input.readMessage(Addr.parser(), extensionRegistry);
                            if (subBuilder != null) {
                                subBuilder.mergeFrom(addr_);
                                addr_ = subBuilder.buildPartial();
                            }

                            break;
                        }
                    }
                }
            } catch (com.google.protobuf.InvalidProtocolBufferException e) {
                throw e.setUnfinishedMessage(this);
            } catch (java.io.IOException e) {
                throw new com.google.protobuf.InvalidProtocolBufferException(
                        e).setUnfinishedMessage(this);
            } finally {
                makeExtensionsImmutable();
            }
        }

        public static final com.google.protobuf.Descriptors.Descriptor
        getDescriptor() {
            return PersonFactory.internal_static_Person_descriptor;
        }

        protected FieldAccessorTable
        internalGetFieldAccessorTable() {
            return PersonFactory.internal_static_Person_fieldAccessorTable
                    .ensureFieldAccessorsInitialized(
                            Person.class, Builder.class);
        }

        public static final int ID_FIELD_NUMBER = 1;
        private int id_;

        /**
         * <code>optional int32 id = 1;</code>
         */
        public int getId() {
            return id_;
        }

        public static final int NAME_FIELD_NUMBER = 2;
        private volatile Object name_;

        /**
         * <code>optional string name = 2;</code>
         */
        public String getName() {
            Object ref = name_;
            if (ref instanceof String) {
                return (String) ref;
            } else {
                com.google.protobuf.ByteString bs =
                        (com.google.protobuf.ByteString) ref;
                String s = bs.toStringUtf8();
                name_ = s;
                return s;
            }
        }

        /**
         * <code>optional string name = 2;</code>
         */
        public com.google.protobuf.ByteString
        getNameBytes() {
            Object ref = name_;
            if (ref instanceof String) {
                com.google.protobuf.ByteString b =
                        com.google.protobuf.ByteString.copyFromUtf8(
                                (String) ref);
                name_ = b;
                return b;
            } else {
                return (com.google.protobuf.ByteString) ref;
            }
        }

        public static final int AGE_FIELD_NUMBER = 3;
        private int age_;

        /**
         * <code>optional int32 age = 3;</code>
         */
        public int getAge() {
            return age_;
        }

        public static final int ADDR_FIELD_NUMBER = 4;
        private Addr addr_;

        /**
         * <code>optional .Addr addr = 4;</code>
         */
        public boolean hasAddr() {
            return addr_ != null;
        }

        /**
         * <code>optional .Addr addr = 4;</code>
         */
        public Addr getAddr() {
            return addr_ == null ? Addr.getDefaultInstance() : addr_;
        }

        /**
         * <code>optional .Addr addr = 4;</code>
         */
        public AddrOrBuilder getAddrOrBuilder() {
            return getAddr();
        }

        private byte memoizedIsInitialized = -1;

        public final boolean isInitialized() {
            byte isInitialized = memoizedIsInitialized;
            if (isInitialized == 1) return true;
            if (isInitialized == 0) return false;

            memoizedIsInitialized = 1;
            return true;
        }

        public void writeTo(com.google.protobuf.CodedOutputStream output)
                throws java.io.IOException {
            if (id_ != 0) {
                output.writeInt32(1, id_);
            }
            if (!getNameBytes().isEmpty()) {
                com.google.protobuf.GeneratedMessageV3.writeString(output, 2, name_);
            }
            if (age_ != 0) {
                output.writeInt32(3, age_);
            }
            if (addr_ != null) {
                output.writeMessage(4, getAddr());
            }
        }

        public int getSerializedSize() {
            int size = memoizedSize;
            if (size != -1) return size;

            size = 0;
            if (id_ != 0) {
                size += com.google.protobuf.CodedOutputStream
                        .computeInt32Size(1, id_);
            }
            if (!getNameBytes().isEmpty()) {
                size += com.google.protobuf.GeneratedMessageV3.computeStringSize(2, name_);
            }
            if (age_ != 0) {
                size += com.google.protobuf.CodedOutputStream
                        .computeInt32Size(3, age_);
            }
            if (addr_ != null) {
                size += com.google.protobuf.CodedOutputStream
                        .computeMessageSize(4, getAddr());
            }
            memoizedSize = size;
            return size;
        }

        private static final long serialVersionUID = 0L;

        @Override
        public boolean equals(final Object obj) {
            if (obj == this) {
                return true;
            }
            if (!(obj instanceof Person)) {
                return super.equals(obj);
            }
            Person other = (Person) obj;

            boolean result = true;
            result = result && (getId()
                    == other.getId());
            result = result && getName()
                    .equals(other.getName());
            result = result && (getAge()
                    == other.getAge());
            result = result && (hasAddr() == other.hasAddr());
            if (hasAddr()) {
                result = result && getAddr()
                        .equals(other.getAddr());
            }
            return result;
        }

        @Override
        public int hashCode() {
            if (memoizedHashCode != 0) {
                return memoizedHashCode;
            }
            int hash = 41;
            hash = (19 * hash) + getDescriptorForType().hashCode();
            hash = (37 * hash) + ID_FIELD_NUMBER;
            hash = (53 * hash) + getId();
            hash = (37 * hash) + NAME_FIELD_NUMBER;
            hash = (53 * hash) + getName().hashCode();
            hash = (37 * hash) + AGE_FIELD_NUMBER;
            hash = (53 * hash) + getAge();
            if (hasAddr()) {
                hash = (37 * hash) + ADDR_FIELD_NUMBER;
                hash = (53 * hash) + getAddr().hashCode();
            }
            hash = (29 * hash) + unknownFields.hashCode();
            memoizedHashCode = hash;
            return hash;
        }

        public static Person parseFrom(
                com.google.protobuf.ByteString data)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data);
        }

        public static Person parseFrom(
                com.google.protobuf.ByteString data,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data, extensionRegistry);
        }

        public static Person parseFrom(byte[] data)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data);
        }

        public static Person parseFrom(
                byte[] data,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data, extensionRegistry);
        }

        public static Person parseFrom(java.io.InputStream input)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input);
        }

        public static Person parseFrom(
                java.io.InputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input, extensionRegistry);
        }

        public static Person parseDelimitedFrom(java.io.InputStream input)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseDelimitedWithIOException(PARSER, input);
        }

        public static Person parseDelimitedFrom(
                java.io.InputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseDelimitedWithIOException(PARSER, input, extensionRegistry);
        }

        public static Person parseFrom(
                com.google.protobuf.CodedInputStream input)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input);
        }

        public static Person parseFrom(
                com.google.protobuf.CodedInputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input, extensionRegistry);
        }

        public Builder newBuilderForType() {
            return newBuilder();
        }

        public static Builder newBuilder() {
            return DEFAULT_INSTANCE.toBuilder();
        }

        public static Builder newBuilder(Person prototype) {
            return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
        }

        public Builder toBuilder() {
            return this == DEFAULT_INSTANCE
                    ? new Builder() : new Builder().mergeFrom(this);
        }

        @Override
        protected Builder newBuilderForType(
                BuilderParent parent) {
            Builder builder = new Builder(parent);
            return builder;
        }

        /**
         * Protobuf type {@code Person}
         */
        public static final class Builder extends
                com.google.protobuf.GeneratedMessageV3.Builder<Builder> implements
                // @@protoc_insertion_point(builder_implements:Person)
                PersonOrBuilder {
            public static final com.google.protobuf.Descriptors.Descriptor
            getDescriptor() {
                return PersonFactory.internal_static_Person_descriptor;
            }

            protected FieldAccessorTable
            internalGetFieldAccessorTable() {
                return PersonFactory.internal_static_Person_fieldAccessorTable
                        .ensureFieldAccessorsInitialized(
                                Person.class, Builder.class);
            }

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            private Builder() {
                maybeForceBuilderInitialization();
            }

            private Builder(
                    BuilderParent parent) {
                super(parent);
                maybeForceBuilderInitialization();
            }

            private void maybeForceBuilderInitialization() {
                if (com.google.protobuf.GeneratedMessageV3
                        .alwaysUseFieldBuilders) {
                }
            }

            public Builder clear() {
                super.clear();
                id_ = 0;

                name_ = "";

                age_ = 0;

                if (addrBuilder_ == null) {
                    addr_ = null;
                } else {
                    addr_ = null;
                    addrBuilder_ = null;
                }
                return this;
            }

            public com.google.protobuf.Descriptors.Descriptor
            getDescriptorForType() {
                return PersonFactory.internal_static_Person_descriptor;
            }

            public Person getDefaultInstanceForType() {
                return Person.getDefaultInstance();
            }

            public Person build() {
                Person result = buildPartial();
                if (!result.isInitialized()) {
                    throw newUninitializedMessageException(result);
                }
                return result;
            }

            public Person buildPartial() {
                Person result = new Person(this);
                result.id_ = id_;
                result.name_ = name_;
                result.age_ = age_;
                if (addrBuilder_ == null) {
                    result.addr_ = addr_;
                } else {
                    result.addr_ = addrBuilder_.build();
                }
                onBuilt();
                return result;
            }

            public Builder clone() {
                return (Builder) super.clone();
            }

            public Builder setField(
                    com.google.protobuf.Descriptors.FieldDescriptor field,
                    Object value) {
                return (Builder) super.setField(field, value);
            }

            public Builder clearField(
                    com.google.protobuf.Descriptors.FieldDescriptor field) {
                return (Builder) super.clearField(field);
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            public Builder clearOneof(
                    com.google.protobuf.Descriptors.OneofDescriptor oneof) {
                return (Builder) super.clearOneof(oneof);
            }

            public Builder setRepeatedField(
                    com.google.protobuf.Descriptors.FieldDescriptor field,
                    int index, Object value) {
                return (Builder) super.setRepeatedField(field, index, value);
            }

            public Builder addRepeatedField(
                    com.google.protobuf.Descriptors.FieldDescriptor field,
                    Object value) {
                return (Builder) super.addRepeatedField(field, value);
            }

            public Builder mergeFrom(com.google.protobuf.Message other) {
                if (other instanceof Person) {
                    return mergeFrom((Person) other);
                } else {
                    super.mergeFrom(other);
                    return this;
                }
            }

            public Builder mergeFrom(Person other) {
                if (other == Person.getDefaultInstance()) return this;
                if (other.getId() != 0) {
                    setId(other.getId());
                }
                if (!other.getName().isEmpty()) {
                    name_ = other.name_;
                    onChanged();
                }
                if (other.getAge() != 0) {
                    setAge(other.getAge());
                }
                if (other.hasAddr()) {
                    mergeAddr(other.getAddr());
                }
                onChanged();
                return this;
            }

            public final boolean isInitialized() {
                return true;
            }

            public Builder mergeFrom(
                    com.google.protobuf.CodedInputStream input,
                    com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                    throws java.io.IOException {
                Person parsedMessage = null;
                try {
                    parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
                } catch (com.google.protobuf.InvalidProtocolBufferException e) {
                    parsedMessage = (Person) e.getUnfinishedMessage();
                    throw e.unwrapIOException();
                } finally {
                    if (parsedMessage != null) {
                        mergeFrom(parsedMessage);
                    }
                }
                return this;
            }

            private int id_;

            /**
             * <code>optional int32 id = 1;</code>
             */
            public int getId() {
                return id_;
            }

            /**
             * <code>optional int32 id = 1;</code>
             */
            public Builder setId(int value) {

                id_ = value;
                onChanged();
                return this;
            }

            /**
             * <code>optional int32 id = 1;</code>
             */
            public Builder clearId() {

                id_ = 0;
                onChanged();
                return this;
            }

            private Object name_ = "";

            /**
             * <code>optional string name = 2;</code>
             */
            public String getName() {
                Object ref = name_;
                if (!(ref instanceof String)) {
                    com.google.protobuf.ByteString bs =
                            (com.google.protobuf.ByteString) ref;
                    String s = bs.toStringUtf8();
                    name_ = s;
                    return s;
                } else {
                    return (String) ref;
                }
            }

            /**
             * <code>optional string name = 2;</code>
             */
            public com.google.protobuf.ByteString
            getNameBytes() {
                Object ref = name_;
                if (ref instanceof String) {
                    com.google.protobuf.ByteString b =
                            com.google.protobuf.ByteString.copyFromUtf8(
                                    (String) ref);
                    name_ = b;
                    return b;
                } else {
                    return (com.google.protobuf.ByteString) ref;
                }
            }

            /**
             * <code>optional string name = 2;</code>
             */
            public Builder setName(
                    String value) {
                if (value == null) {
                    throw new NullPointerException();
                }

                name_ = value;
                onChanged();
                return this;
            }

            /**
             * <code>optional string name = 2;</code>
             */
            public Builder clearName() {

                name_ = getDefaultInstance().getName();
                onChanged();
                return this;
            }

            /**
             * <code>optional string name = 2;</code>
             */
            public Builder setNameBytes(
                    com.google.protobuf.ByteString value) {
                if (value == null) {
                    throw new NullPointerException();
                }
                checkByteStringIsUtf8(value);

                name_ = value;
                onChanged();
                return this;
            }

            private int age_;

            /**
             * <code>optional int32 age = 3;</code>
             */
            public int getAge() {
                return age_;
            }

            /**
             * <code>optional int32 age = 3;</code>
             */
            public Builder setAge(int value) {

                age_ = value;
                onChanged();
                return this;
            }

            /**
             * <code>optional int32 age = 3;</code>
             */
            public Builder clearAge() {

                age_ = 0;
                onChanged();
                return this;
            }

            private Addr addr_ = null;
            private com.google.protobuf.SingleFieldBuilderV3<
                    Addr, Addr.Builder, AddrOrBuilder> addrBuilder_;

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public boolean hasAddr() {
                return addrBuilder_ != null || addr_ != null;
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public Addr getAddr() {
                if (addrBuilder_ == null) {
                    return addr_ == null ? Addr.getDefaultInstance() : addr_;
                } else {
                    return addrBuilder_.getMessage();
                }
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public Builder setAddr(Addr value) {
                if (addrBuilder_ == null) {
                    if (value == null) {
                        throw new NullPointerException();
                    }
                    addr_ = value;
                    onChanged();
                } else {
                    addrBuilder_.setMessage(value);
                }

                return this;
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public Builder setAddr(
                    Addr.Builder builderForValue) {
                if (addrBuilder_ == null) {
                    addr_ = builderForValue.build();
                    onChanged();
                } else {
                    addrBuilder_.setMessage(builderForValue.build());
                }

                return this;
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public Builder mergeAddr(Addr value) {
                if (addrBuilder_ == null) {
                    if (addr_ != null) {
                        addr_ =
                                Addr.newBuilder(addr_).mergeFrom(value).buildPartial();
                    } else {
                        addr_ = value;
                    }
                    onChanged();
                } else {
                    addrBuilder_.mergeFrom(value);
                }

                return this;
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public Builder clearAddr() {
                if (addrBuilder_ == null) {
                    addr_ = null;
                    onChanged();
                } else {
                    addr_ = null;
                    addrBuilder_ = null;
                }

                return this;
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public Addr.Builder getAddrBuilder() {

                onChanged();
                return getAddrFieldBuilder().getBuilder();
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            public AddrOrBuilder getAddrOrBuilder() {
                if (addrBuilder_ != null) {
                    return addrBuilder_.getMessageOrBuilder();
                } else {
                    return addr_ == null ?
                            Addr.getDefaultInstance() : addr_;
                }
            }

            /**
             * <code>optional .Addr addr = 4;</code>
             */
            private com.google.protobuf.SingleFieldBuilderV3<
                    Addr, Addr.Builder, AddrOrBuilder>
            getAddrFieldBuilder() {
                if (addrBuilder_ == null) {
                    addrBuilder_ = new com.google.protobuf.SingleFieldBuilderV3<
                            Addr, Addr.Builder, AddrOrBuilder>(
                            getAddr(),
                            getParentForChildren(),
                            isClean());
                    addr_ = null;
                }
                return addrBuilder_;
            }

            public final Builder setUnknownFields(
                    final com.google.protobuf.UnknownFieldSet unknownFields) {
                return this;
            }

            public final Builder mergeUnknownFields(
                    final com.google.protobuf.UnknownFieldSet unknownFields) {
                return this;
            }


            // @@protoc_insertion_point(builder_scope:Person)
        }

        // @@protoc_insertion_point(class_scope:Person)
        private static final Person DEFAULT_INSTANCE;

        static {
            DEFAULT_INSTANCE = new Person();
        }

        public static Person getDefaultInstance() {
            return DEFAULT_INSTANCE;
        }

        private static final com.google.protobuf.Parser<Person>
                PARSER = new com.google.protobuf.AbstractParser<Person>() {
            public Person parsePartialFrom(
                    com.google.protobuf.CodedInputStream input,
                    com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                    throws com.google.protobuf.InvalidProtocolBufferException {
                return new Person(input, extensionRegistry);
            }
        };

        public static com.google.protobuf.Parser<Person> parser() {
            return PARSER;
        }

        @Override
        public com.google.protobuf.Parser<Person> getParserForType() {
            return PARSER;
        }

        public Person getDefaultInstanceForType() {
            return DEFAULT_INSTANCE;
        }

    }

    public interface AddrOrBuilder extends
            // @@protoc_insertion_point(interface_extends:Addr)
            com.google.protobuf.MessageOrBuilder {

        /**
         * <code>optional string contry = 1;</code>
         */
        String getContry();

        /**
         * <code>optional string contry = 1;</code>
         */
        com.google.protobuf.ByteString
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        /**
         * <code>optional string city = 2;</code>
         */
        String getCity();

        /**
         * <code>optional string city = 2;</code>
         */
        com.google.protobuf.ByteString
        getCityBytes();
    }

    /**
     * Protobuf type {@code Addr}
     */
    public static final class Addr extends
            com.google.protobuf.GeneratedMessageV3 implements
            // @@protoc_insertion_point(message_implements:Addr)
            AddrOrBuilder {
        // Use Addr.newBuilder() to construct.
        private Addr(com.google.protobuf.GeneratedMessageV3.Builder<?> builder) {
            super(builder);
        }

        private Addr() {
            contry_ = "";
            city_ = "";
        }

        @Override
        public final com.google.protobuf.UnknownFieldSet
        getUnknownFields() {
            return com.google.protobuf.UnknownFieldSet.getDefaultInstance();
        }

        private Addr(
                com.google.protobuf.CodedInputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws com.google.protobuf.InvalidProtocolBufferException {
            this();
            int mutable_bitField0_ = 0;
            try {
                boolean done = false;
                while (!done) {
                    int tag = input.readTag();
                    switch (tag) {
                        case 0:
                            done = true;
                            break;
                        default: {
                            if (!input.skipField(tag)) {
                                done = true;
                            }
                            break;
                        }
                        case 10: {
                            String s = input.readStringRequireUtf8();

                            contry_ = s;
                            break;
                        }
                        case 18: {
                            String s = input.readStringRequireUtf8();

                            city_ = s;
                            break;
                        }
                    }
                }
            } catch (com.google.protobuf.InvalidProtocolBufferException e) {
                throw e.setUnfinishedMessage(this);
            } catch (java.io.IOException e) {
                throw new com.google.protobuf.InvalidProtocolBufferException(
                        e).setUnfinishedMessage(this);
            } finally {
                makeExtensionsImmutable();
            }
        }

        public static final com.google.protobuf.Descriptors.Descriptor
        getDescriptor() {
            return PersonFactory.internal_static_Addr_descriptor;
        }

        protected FieldAccessorTable
        internalGetFieldAccessorTable() {
            return PersonFactory.internal_static_Addr_fieldAccessorTable
                    .ensureFieldAccessorsInitialized(
                            Addr.class, Builder.class);
        }

        public static final int CONTRY_FIELD_NUMBER = 1;
        private volatile Object contry_;

        /**
         * <code>optional string contry = 1;</code>
         */
        public String getContry() {
            Object ref = contry_;
            if (ref instanceof String) {
                return (String) ref;
            } else {
                com.google.protobuf.ByteString bs =
                        (com.google.protobuf.ByteString) ref;
                String s = bs.toStringUtf8();
                contry_ = s;
                return s;
            }
        }

        /**
         * <code>optional string contry = 1;</code>
         */
        public com.google.protobuf.ByteString
        getContryBytes() {
            Object ref = contry_;
            if (ref instanceof String) {
                com.google.protobuf.ByteString b =
                        com.google.protobuf.ByteString.copyFromUtf8(
                                (String) ref);
                contry_ = b;
                return b;
            } else {
                return (com.google.protobuf.ByteString) ref;
            }
        }

        public static final int CITY_FIELD_NUMBER = 2;
        private volatile Object city_;

        /**
         * <code>optional string city = 2;</code>
         */
        public String getCity() {
            Object ref = city_;
            if (ref instanceof String) {
                return (String) ref;
            } else {
                com.google.protobuf.ByteString bs =
                        (com.google.protobuf.ByteString) ref;
                String s = bs.toStringUtf8();
                city_ = s;
                return s;
            }
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        /**
         * <code>optional string city = 2;</code>
         */
        public com.google.protobuf.ByteString
        getCityBytes() {
            Object ref = city_;
            if (ref instanceof String) {
                com.google.protobuf.ByteString b =
                        com.google.protobuf.ByteString.copyFromUtf8(
                                (String) ref);
                city_ = b;
                return b;
            } else {
                return (com.google.protobuf.ByteString) ref;
            }
        }

        private byte memoizedIsInitialized = -1;

        public final boolean isInitialized() {
            byte isInitialized = memoizedIsInitialized;
            if (isInitialized == 1) return true;
            if (isInitialized == 0) return false;

            memoizedIsInitialized = 1;
            return true;
        }

        public void writeTo(com.google.protobuf.CodedOutputStream output)
                throws java.io.IOException {
            if (!getContryBytes().isEmpty()) {
                com.google.protobuf.GeneratedMessageV3.writeString(output, 1, contry_);
            }
            if (!getCityBytes().isEmpty()) {
                com.google.protobuf.GeneratedMessageV3.writeString(output, 2, city_);
            }
        }

        public int getSerializedSize() {
            int size = memoizedSize;
            if (size != -1) return size;

            size = 0;
            if (!getContryBytes().isEmpty()) {
                size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, contry_);
            }
            if (!getCityBytes().isEmpty()) {
                size += com.google.protobuf.GeneratedMessageV3.computeStringSize(2, city_);
            }
            memoizedSize = size;
            return size;
        }

        private static final long serialVersionUID = 0L;

        @Override
        public boolean equals(final Object obj) {
            if (obj == this) {
                return true;
            }
            if (!(obj instanceof Addr)) {
                return super.equals(obj);
            }
            Addr other = (Addr) obj;

            boolean result = true;
            result = result && getContry()
                    .equals(other.getContry());
            result = result && getCity()
                    .equals(other.getCity());
            return result;
        }

        @Override
        public int hashCode() {
            if (memoizedHashCode != 0) {
                return memoizedHashCode;
            }
            int hash = 41;
            hash = (19 * hash) + getDescriptorForType().hashCode();
            hash = (37 * hash) + CONTRY_FIELD_NUMBER;
            hash = (53 * hash) + getContry().hashCode();
            hash = (37 * hash) + CITY_FIELD_NUMBER;
            hash = (53 * hash) + getCity().hashCode();
            hash = (29 * hash) + unknownFields.hashCode();
            memoizedHashCode = hash;
            return hash;
        }

        public static Addr parseFrom(
                com.google.protobuf.ByteString data)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data);
        }

        public static Addr parseFrom(
                com.google.protobuf.ByteString data,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data, extensionRegistry);
        }

        public static Addr parseFrom(byte[] data)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data);
        }

        public static Addr parseFrom(
                byte[] data,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws com.google.protobuf.InvalidProtocolBufferException {
            return PARSER.parseFrom(data, extensionRegistry);
        }

        public static Addr parseFrom(java.io.InputStream input)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input);
        }

        public static Addr parseFrom(
                java.io.InputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input, extensionRegistry);
        }

        public static Addr parseDelimitedFrom(java.io.InputStream input)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseDelimitedWithIOException(PARSER, input);
        }

        public static Addr parseDelimitedFrom(
                java.io.InputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseDelimitedWithIOException(PARSER, input, extensionRegistry);
        }

        public static Addr parseFrom(
                com.google.protobuf.CodedInputStream input)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input);
        }

        public static Addr parseFrom(
                com.google.protobuf.CodedInputStream input,
                com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                throws java.io.IOException {
            return com.google.protobuf.GeneratedMessageV3
                    .parseWithIOException(PARSER, input, extensionRegistry);
        }

        public Builder newBuilderForType() {
            return newBuilder();
        }

        public static Builder newBuilder() {
            return DEFAULT_INSTANCE.toBuilder();
        }

        public static Builder newBuilder(Addr prototype) {
            return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
        }

        public Builder toBuilder() {
            return this == DEFAULT_INSTANCE
                    ? new Builder() : new Builder().mergeFrom(this);
        }

        @Override
        protected Builder newBuilderForType(
                BuilderParent parent) {
            Builder builder = new Builder(parent);
            return builder;
        }

        /**
         * Protobuf type {@code Addr}
         */
        public static final class Builder extends
                com.google.protobuf.GeneratedMessageV3.Builder<Builder> implements
                // @@protoc_insertion_point(builder_implements:Addr)
                AddrOrBuilder {
            public static final com.google.protobuf.Descriptors.Descriptor
            getDescriptor() {
                return PersonFactory.internal_static_Addr_descriptor;
            }

            protected FieldAccessorTable
            internalGetFieldAccessorTable() {
                return PersonFactory.internal_static_Addr_fieldAccessorTable
                        .ensureFieldAccessorsInitialized(
                                Addr.class, Builder.class);
            }

            // Construct using com.gp.lock.serizlizer.protobuf.PersonFactory.Addr.newBuilder()
            private Builder() {
                maybeForceBuilderInitialization();
            }

            private Builder(
                    BuilderParent parent) {
                super(parent);
                maybeForceBuilderInitialization();
            }

            private void maybeForceBuilderInitialization() {
                if (com.google.protobuf.GeneratedMessageV3
                        .alwaysUseFieldBuilders) {
                }
            }

            public Builder clear() {
                super.clear();
                contry_ = "";

                city_ = "";

                return this;
            }

            public com.google.protobuf.Descriptors.Descriptor
            getDescriptorForType() {
                return PersonFactory.internal_static_Addr_descriptor;
            }

            public Addr getDefaultInstanceForType() {
                return Addr.getDefaultInstance();
            }

            public Addr build() {
                Addr result = buildPartial();
                if (!result.isInitialized()) {
                    throw newUninitializedMessageException(result);
                }
                return result;
            }

            public Addr buildPartial() {
                Addr result = new Addr(this);
                result.contry_ = contry_;
                result.city_ = city_;
                onBuilt();
                return result;
            }

            public Builder clone() {
                return (Builder) super.clone();
            }

            public Builder setField(
                    com.google.protobuf.Descriptors.FieldDescriptor field,
                    Object value) {
                return (Builder) super.setField(field, value);
            }

            public Builder clearField(
                    com.google.protobuf.Descriptors.FieldDescriptor field) {
                return (Builder) super.clearField(field);
            }

            public Builder clearOneof(
                    com.google.protobuf.Descriptors.OneofDescriptor oneof) {
                return (Builder) super.clearOneof(oneof);
            }

            public Builder setRepeatedField(
                    com.google.protobuf.Descriptors.FieldDescriptor field,
                    int index, Object value) {
                return (Builder) super.setRepeatedField(field, index, value);
            }

            public Builder addRepeatedField(
                    com.google.protobuf.Descriptors.FieldDescriptor field,
                    Object value) {
                return (Builder) super.addRepeatedField(field, value);
            }

            public Builder mergeFrom(com.google.protobuf.Message other) {
                if (other instanceof Addr) {
                    return mergeFrom((Addr) other);
                } else {
                    super.mergeFrom(other);
                    return this;
                }
            }

            public Builder mergeFrom(Addr other) {
                if (other == Addr.getDefaultInstance()) return this;
                if (!other.getContry().isEmpty()) {
                    contry_ = other.contry_;
                    onChanged();
                }
                if (!other.getCity().isEmpty()) {
                    city_ = other.city_;
                    onChanged();
                }
                onChanged();
                return this;
            }

            public final boolean isInitialized() {
                return true;
            }

            public Builder mergeFrom(
                    com.google.protobuf.CodedInputStream input,
                    com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                    throws java.io.IOException {
                Addr parsedMessage = null;
                try {
                    parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
                } catch (com.google.protobuf.InvalidProtocolBufferException e) {
                    parsedMessage = (Addr) e.getUnfinishedMessage();
                    throw e.unwrapIOException();
                } finally {
                    if (parsedMessage != null) {
                        mergeFrom(parsedMessage);
                    }
                }
                return this;
            }

            private Object contry_ = "";

            /**
             * <code>optional string contry = 1;</code>
             */
            public String getContry() {
                Object ref = contry_;
                if (!(ref instanceof String)) {
                    com.google.protobuf.ByteString bs =
                            (com.google.protobuf.ByteString) ref;
                    String s = bs.toStringUtf8();
                    contry_ = s;
                    return s;
                } else {
                    return (String) ref;
                }
            }

            /**
             * <code>optional string contry = 1;</code>
             */
            public com.google.protobuf.ByteString
            getContryBytes() {
                Object ref = contry_;
                if (ref instanceof String) {
                    com.google.protobuf.ByteString b =
                            com.google.protobuf.ByteString.copyFromUtf8(
                                    (String) ref);
                    contry_ = b;
                    return b;
                } else {
                    return (com.google.protobuf.ByteString) ref;
                }
            }

            /**
             * <code>optional string contry = 1;</code>
             */
            public Builder setContry(
                    String value) {
                if (value == null) {
                    throw new NullPointerException();
                }

                contry_ = value;
                onChanged();
                return this;
            }

            /**
             * <code>optional string contry = 1;</code>
             */
            public Builder clearContry() {

                contry_ = getDefaultInstance().getContry();
                onChanged();
                return this;
            }

            /**
             * <code>optional string contry = 1;</code>
             */
            public Builder setContryBytes(
                    com.google.protobuf.ByteString value) {
                if (value == null) {
                    throw new NullPointerException();
                }
                checkByteStringIsUtf8(value);

                contry_ = value;
                onChanged();
                return this;
            }

            private Object city_ = "";

            /**
             * <code>optional string city = 2;</code>
             */
            public String getCity() {
                Object ref = city_;
                if (!(ref instanceof String)) {
                    com.google.protobuf.ByteString bs =
                            (com.google.protobuf.ByteString) ref;
                    String s = bs.toStringUtf8();
                    city_ = s;
                    return s;
                } else {
                    return (String) ref;
                }
            }

            /**
             * <code>optional string city = 2;</code>
             */
            public com.google.protobuf.ByteString
            getCityBytes() {
                Object ref = city_;
                if (ref instanceof String) {
                    com.google.protobuf.ByteString b =
                            com.google.protobuf.ByteString.copyFromUtf8(
                                    (String) ref);
                    city_ = b;
                    return b;
                } else {
                    return (com.google.protobuf.ByteString) ref;
                }
            }

            /**
             * <code>optional string city = 2;</code>
             */
            public Builder setCity(
                    String value) {
                if (value == null) {
                    throw new NullPointerException();
                }

                city_ = value;
                onChanged();
                return this;
            }

            /**
             * <code>optional string city = 2;</code>
             */
            public Builder clearCity() {

                city_ = getDefaultInstance().getCity();
                onChanged();
                return this;
            }

            /**
             * <code>optional string city = 2;</code>
             */
            public Builder setCityBytes(
                    com.google.protobuf.ByteString value) {
                if (value == null) {
                    throw new NullPointerException();
                }
                checkByteStringIsUtf8(value);

                city_ = value;
                onChanged();
                return this;
            }

            public final Builder setUnknownFields(
                    final com.google.protobuf.UnknownFieldSet unknownFields) {
                return this;
            }

            public final Builder mergeUnknownFields(
                    final com.google.protobuf.UnknownFieldSet unknownFields) {
                return this;
            }


            // @@protoc_insertion_point(builder_scope:Addr)
        }

        // @@protoc_insertion_point(class_scope:Addr)
        private static final Addr DEFAULT_INSTANCE;

        static {
            DEFAULT_INSTANCE = new Addr();
        }

        public static Addr getDefaultInstance() {
            return DEFAULT_INSTANCE;
        }

        private static final com.google.protobuf.Parser<Addr>
                PARSER = new com.google.protobuf.AbstractParser<Addr>() {
            public Addr parsePartialFrom(
                    com.google.protobuf.CodedInputStream input,
                    com.google.protobuf.ExtensionRegistryLite extensionRegistry)
                    throws com.google.protobuf.InvalidProtocolBufferException {
                return new Addr(input, extensionRegistry);
            }
        };

        public static com.google.protobuf.Parser<Addr> parser() {
            return PARSER;
        }

        @Override
        public com.google.protobuf.Parser<Addr> getParserForType() {
            return PARSER;
        }

        public Addr getDefaultInstanceForType() {
            return DEFAULT_INSTANCE;
        }

    }

    private static final com.google.protobuf.Descriptors.Descriptor
            internal_static_Person_descriptor;
    private static final
    com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
            internal_static_Person_fieldAccessorTable;
    private static final com.google.protobuf.Descriptors.Descriptor
            internal_static_Addr_descriptor;
    private static final
    com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
            internal_static_Addr_fieldAccessorTable;

    public static com.google.protobuf.Descriptors.FileDescriptor
    getDescriptor() {
        return descriptor;
    }

    private static com.google.protobuf.Descriptors.FileDescriptor
            descriptor;

    static {
        String[] descriptorData = {
                "\n\014person.proto\"D\n\006Person\022\n\n\002id\030\001 \001(\005\022\014\n\004" +
                        "name\030\002 \001(\t\022\013\n\003age\030\003 \001(\005\022\023\n\004addr\030\004 \001(\0132\005." +
                        "Addr\"$\n\004Addr\022\016\n\006contry\030\001 \001(\t\022\014\n\004city\030\002 \001" +
                        "(\tB0\n\037com.gp.lock.serizlizer.protobufB\rP" +
                        "ersonFactoryb\006proto3"
        };
        com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
                new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
                    public com.google.protobuf.ExtensionRegistry assignDescriptors(
                            com.google.protobuf.Descriptors.FileDescriptor root) {
                        descriptor = root;
                        return null;
                    }
                };
        com.google.protobuf.Descriptors.FileDescriptor
                .internalBuildGeneratedFileFrom(descriptorData,
                        new com.google.protobuf.Descriptors.FileDescriptor[]{
                        }, assigner);
        internal_static_Person_descriptor =
                getDescriptor().getMessageTypes().get(0);
        internal_static_Person_fieldAccessorTable = new
                com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
                internal_static_Person_descriptor,
                new String[]{"Id", "Name", "Age", "Addr",});
        internal_static_Addr_descriptor =
                getDescriptor().getMessageTypes().get(1);
        internal_static_Addr_fieldAccessorTable = new
                com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
                internal_static_Addr_descriptor,
                new String[]{"Contry", "City",});
    }

    // @@protoc_insertion_point(outer_class_scope)
}

package com.gp.lock.serizlizer.protobuf;

import java.net.ServerSocket;
import java.net.Socket;

public class Server {

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub
        ServerSocket serverSock = new ServerSocket(3030);
        while (true) {
            Socket sock = serverSock.accept();
            byte[] msg = new byte[256];
            sock.getInputStream().read(msg);
            int msgBodyLen = msg[0];
            System.out.println("msg body len:" + msgBodyLen);
            byte[] msgbody = new byte[msgBodyLen];
            System.arraycopy(msg, 1, msgbody, 0, msgBodyLen);

            System.out.println("msgbody = " + new String(msgbody));
            PersonFactory.Person person = PersonFactory.Person.parseFrom(msgbody);

            System.out.println("Receive:");
            System.out.println(person);
        }

    }

}

package com.gp.lock.serizlizer.protobuf;

import com.gp.lock.serizlizer.protobuf.PersonFactory.Addr;
import com.gp.lock.serizlizer.protobuf.PersonFactory.Person;

import java.net.Socket;

public class Client {

    public static void main(String[] args) throws Exception {
        Socket socket = new Socket("127.0.0.1", 3030);

        Person.Builder person = Person.newBuilder();

        Addr.Builder addr = Addr.newBuilder();
        addr.setContry("china").setCity("shenzhen");

        person.setId(1).setAge(12).setName("ccf");
        person.setAddr(addr);

        byte[] messageBody = person.build().toByteArray();

        System.out.println("messageBody = " + new String(messageBody));
        int headerLen = 1;
        byte[] message = new byte[headerLen + messageBody.length];
        message[0] = (byte) messageBody.length;
        System.arraycopy(messageBody, 0, message, 1, messageBody.length);
        System.out.println("msg len:" + message.length);
        socket.getOutputStream().write(message);
    }

}

结果

"C:\Program Files\Java\jdk1.8.0_211\bin\java.exe" -Dvisualvm.id=443604366717400 "-javaagent:D:\DevelopTools\IDEA\IntelliJ IDEA 2019.2.2\lib\idea_rt.jar=12578:D:\DevelopTools\IDEA\IntelliJ IDEA 2019.2.2\bin" -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Java\jdk1.8.0_211\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_211\jre\lib\rt.jar;E:\CODE\Architecture\serializer\target\classes;C:\Users\zwz\.m2\repository\com\thoughtworks\xstream\xstream\1.4.10\xstream-1.4.10.jar;C:\Users\zwz\.m2\repository\xmlpull\xmlpull\1.1.3.1\xmlpull-1.1.3.1.jar;C:\Users\zwz\.m2\repository\xpp3\xpp3_min\1.1.4c\xpp3_min-1.1.4c.jar;C:\Users\zwz\.m2\repository\com\alibaba\fastjson\1.2.31\fastjson-1.2.31.jar;C:\Users\zwz\.m2\repository\io\netty\netty-all\4.1.45.Final\netty-all-4.1.45.Final.jar;C:\Users\zwz\.m2\repository\junit\junit\4.12\junit-4.12.jar;C:\Users\zwz\.m2\repository\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;C:\Users\zwz\.m2\repository\com\google\protobuf\protobuf-java\3.7.1\protobuf-java-3.7.1.jar" com.gp.lock.serizlizer.protobuf.Server
msg body len:28
msgbody =���ccf�"�
�chinashenzhen
Receive:
id: 1
name: "ccf"
age: 12
addr {
  contry: "china"
  city: "shenzhen"
}

7.3 protostuff

protostuff是一个基于protobuf实现的序列化方法，它较于protobuf最明显的好处是，在几乎不损耗性能的情况下做到了不用我们写.proto文件来实现序列化。

package com.gp.lock.serizlizer.protobuf;

import com.dyuproject.protostuff.LinkedBuffer;
import com.dyuproject.protostuff.ProtostuffIOUtil;
import com.dyuproject.protostuff.runtime.RuntimeSchema;

import java.util.ArrayList;
import java.util.List;

public class ProtostuffTest {

    static RuntimeSchema<Po> poSchema = RuntimeSchema.createFrom(Po.class);

    private static byte[] decode(Po po) {
        return ProtostuffIOUtil.toByteArray(po, poSchema, LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE));
    }

    private static Po ecode(byte[] bytes) {
        Po po = poSchema.newMessage();
        ProtostuffIOUtil.mergeFrom(bytes, po, poSchema);
        return po;
    }

    public static void main(String[] args) {
        InnerPo innerPo = new InnerPo(1, "InnerPo1");
        List<String> list = new ArrayList<String>();
        list.add("a");
        list.add("b");
        Po po = new Po(1, "Fong", "备注", 24, new int[]{1, 2, 3, 4}, innerPo, list);
        byte[] bytes = decode(po);
        System.out.println(bytes.length);
        Po newPo = ecode(bytes);
        System.out.println(newPo);
    }

}

运行结果

65
id:1
name:Fong
remark:备注
age:24
array:[1, 2, 3, 4]
innerPo:1-InnerPo1
more:[a, b]

模式

package com.asiainfo.dacp.brokerframe.protocol.rpc;

import com.dyuproject.protostuff.LinkedBuffer;
import com.dyuproject.protostuff.ProtobufIOUtil;
import com.dyuproject.protostuff.Schema;
import com.dyuproject.protostuff.runtime.RuntimeSchema;
import org.objenesis.Objenesis;
import org.objenesis.ObjenesisStd;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @description: Protostuff 序列化与反序列化工具
 * @date : 2020/6/11 17:02
 * @author: zwz
 */
public class SerializationUtil {

    private static Map<Class<?>, Schema<?>> cacheSchema = new ConcurrentHashMap<>();

    private static Objenesis objenesis = new ObjenesisStd(true);

    public SerializationUtil() {
    }

    private static <T> Schema<T> getSchema(Class<T> cls) {
        Schema<T> schema = (Schema<T>) cacheSchema.get(cls);
        if (schema == null) {
            schema = RuntimeSchema.createFrom(cls);
            cacheSchema.put(cls, schema);
        }
        return schema;
    }

    public static <T> byte[] serialize(T obj) {
        Class<T> cls = (Class<T>) obj.getClass();
        LinkedBuffer buffer = LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE);
        try {
            Schema<T> schema = getSchema(cls);
            //序列化：把 obj 按照 schema 模式 写入到 buffer
            return ProtobufIOUtil.toByteArray(obj, schema, buffer);
        } catch (Exception e) {
            throw new IllegalStateException(e.getMessage(), e);
        } finally {
            buffer.clear();
        }
    }

    public static <T> T deserialized(byte[] data, Class<T> cls) {
        try {
            T message = objenesis.newInstance(cls);
            Schema<T> schema = getSchema(cls);
            //反序列化：将 data 按 schema 模式重建实例 message
            ProtobufIOUtil.mergeFrom(data, message, schema);
            return message;
        } catch (Exception e) {
            throw new IllegalStateException(e.getMessage(), e);
        }
    }
}

7.4 Protocol Buffer 的性能好，主要体现在序列化后的数据体积小 & 序列化速度快，最终使得传输效率高，其原因如下：

序列化速度快的原因：

编码 / 解码方式简单（只需要简单的数学运算 = 位移等等）
采用 Protocol Buffer 自身的框架代码和编译器共同完成

序列化后的数据量体积小（即数据压缩效果好）的原因：

采用了独特的编码方式，如 Varint、Zigzag 编码方式等等
采用 T - L - V 的数据存储方式：减少了分隔符的使用 & 数据存储得紧凑

8. 序列化技术选型

技术层面

序列化空间开销，也就是序列化产生的结果大小，这个影响到传输的性能
序列化过程中消耗的时长，序列化消耗时间过长影响到业务的响应时间
序列化协议是否支持跨平台，跨语言。因为现在的架构更加灵活，如果存在异构系统通信需求，那么这个是必须要考虑的
可扩展性/兼容性，在实际业务开发中，系统往往需要随着需求的快速迭代来实现快速更新，这就要求我们采用的序列化协议基于良好的可扩展性/兼容性，比如在现有的序列化数据结构中新增一个业务字段，不会影响到现有的服务
技术的流行程度，越流行的技术意味着使用的公司多，那么很多坑都已经淌过并且得到了解决，技术解决方案也相对成熟
学习难度和易用性

选型建议

对性能要求不高的场景，可以采用基于 XML 的 SOAP 协议
对性能和间接性有比较高要求的场景，那么 Hessian、Protobuf、Thrift、Avro 都可以。
基于前后端分离，或者独立的对外的 api 服务，选用 JSON 是比较好的，对于调试、可读性都很不错
Avro 设计理念偏于动态类型语言，那么这类的场景使用 Avro 是可以的

序列化

1. 序列化的意义

2. 优劣指标：

3. JDK的序列化：

3.1 一个类只要实现了 java.io.Serializable 接口，那就可以被序列化

3.2 通过输出流 java.io.ObjectOutputStream 和对象输入流 java.io.ObjectInputStream 来实现

3.3 实例

4. 高阶认识

4.1 serialVersionUID 的作用

4.2 静态变量序列化

4.3 父类的序列化

4.4 Transient

5. 序列化实现深拷贝

6. 常见的序列化技术

6.1 使用 JAVA 进行序列化有他的优点，也有他的缺点

6.2 XML 序列化框架

6.3 JSON 序列化

6.4 Hessian 序列化框架

7. Protobuf（Protocol Buffer）序列化框架

7.1 简介

7.2 使用实例

7.3 protostuff

7.4 Protocol Buffer 的性能好，主要体现在序列化后的数据体积小 & 序列化速度快，最终使得传输效率高，其原因如下：

8. 序列化技术选型

技术层面

选型建议

相关文章

网友评论

延伸阅读

深度阅读

栏目导航

热点阅读

序列化

1. 序列化的意义

2. 优劣指标：

3. JDK的序列化：

3.1 一个类只要实现了 java.io.Serializable 接口，那就可以被序列化

3.2 通过输出流 java.io.ObjectOutputStream 和对象输入流 java.io.ObjectInputStream 来实现

3.3 实例

4. 高阶认识

4.1 serialVersionUID 的作用

4.2 静态变量序列化

4.3 父类的序列化

4.4 Transient

5. 序列化实现深拷贝

6. 常见的序列化技术

6.1 使用 JAVA 进行序列化有他的优点，也有他的缺点

6.2 XML 序列化框架

6.3 JSON 序列化

6.4 Hessian 序列化框架

7. Protobuf（Protocol Buffer） 序列化框架

7.1 简介

7.2 使用实例

7.3 protostuff

7.4 Protocol Buffer 的性能好，主要体现在 序列化后的数据体积小 & 序列化速度快，最终使得传输效率高，其原因如下：

8. 序列化技术选型

技术层面

选型建议

相关文章

网友评论

延伸阅读

深度阅读

栏目导航

热点阅读

7. Protobuf（Protocol Buffer）序列化框架

7.4 Protocol Buffer 的性能好，主要体现在序列化后的数据体积小 & 序列化速度快，最终使得传输效率高，其原因如下：