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Android 的进程间通信 Binder——AIDL的入门使用

Android 的进程间通信 Binder——AIDL的入门使用

作者: 在代码下成长 | 来源:发表于2017-11-28 15:39 被阅读177次

    进程间通信系列

    AIDL的入门使用(一)
    AIDL的入门使用(二)
    AIDL的入门使用(三)
    Messenger的入门使用

    目录

    image.png

    序言

    什么概念都省了,直接看怎么使用,主要分两部分,一个是服务端,一个是客户端。更多使用请持续关注。

    AIDL通信的服务端

    1、创建AIDL 的服务端的Moudle ;

    2、在aidl包下创建需要传递的对象Book类,并实现Parcelable 接口(使用Android Studio 的Parcelable 接口生成插件)

    package com.ljp.aidl_server.aidl;
    import android.os.Parcel;
    import android.os.Parcelable;
    /**
     * Created by yuxue on 2017/11/28.
     */
    public class Book implements Parcelable {
        public int id;
        public String name;
        public double price;
        //省略set 、get、构造、toString等方法
        @Override
        public int describeContents() {
            return 0;
        }
        @Override
        public void writeToParcel(Parcel dest, int flags) {
            dest.writeInt(this.id);
            dest.writeString(this.name);
            dest.writeDouble(this.price);
        }
        public Book() {
        }
        protected Book(Parcel in) {
            this.id = in.readInt();
            this.name = in.readString();
            this.price = in.readDouble();
        }
        public static final Parcelable.Creator<Book> CREATOR = new Parcelable.Creator<Book>() {
            @Override
            public Book createFromParcel(Parcel source) {
                return new Book(source);
            }
            @Override
            public Book[] newArray(int size) {
                return new Book[size];
            }
        };
    }
    

    3、鼠标右键单击aidl包——>new ——>AIDL——>AIDL File——>输入接口名称:IMyAidlInterface——>Finish

    image.png image.png image.png
    //Book.aidl文件
    package com.ljp.aidl_server.aidl;//在这里一定要标注包名,与 IMyAidlInterface.aidl文件中的包名相同,否则编译报错
    //注意  parcelable的p字母是小写   ,声明已序列化的类
    parcelable Book; 
    

    4、在新生成的aidl包上鼠标右键新建文件要传递的类名.adil文件,这里要传递的对象为Book类,因此新建Book.aidl,在Book.aidl文件中声明包名和已序列化对应的类。

    image.png image.png

    5、编写IMyAidlInterface.aidl文件,声明客户端调用AIDL的接口,编写好IMyAidlInterface.aidl文件以后 Build——>Make Project(一定要先Make Project以后编译器才不会报错)

    // IMyAidlInterface.aidl
    package com.ljp.aidl_server.aidl;
    // Declare any non-default types here with import statements
    import com.ljp.aidl_server.aidl.Book;//虽然在同一个包中,但还是要进行导包操作,否则会报错。
    interface IMyAidlInterface {
        /**
         * Demonstrates some basic types that you can use as parameters
         * and return values in AIDL.
         */
        void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat,
                double aDouble, String aString);
        //编写客户端可以调用的AIDL接口,
        void addBook(in Book book);//一定要加 in
        List<Book> getBooks();
        void setTag(in String tag);
        String getTag();
        void setNum(in int num);
        int getNum();
    }
    

    6、创建服务端的Service并编写内容,右键单击aidl包——>New ——> Service——> Service——>输入文件名AidlSerVerService,创建IMyAidlInterface.Stub的对象并在onBind方法中返回。(注:IMyAidlInterface.java文件有编译器在Make Project 过程中自动生成,即我们可以不编写前面的aidl文件,只需要编写IMyAidlInterface.java文件也是可以进行进程间通信的)

    image.png
    image.png
    package com.ljp.aidl_server.aidl;
    import android.app.Service;
    import android.content.Intent;
    import android.os.IBinder;
    import android.os.RemoteException;
    import android.text.TextUtils;
    import java.util.ArrayList;
    import java.util.List;
    public class AidlSerVerService extends Service {
        private List<Book> mBookList = new ArrayList<>();
        private String tag = "empty";
        private int num = -1;
        IMyAidlInterface.Stub stub_binder = new IMyAidlInterface.Stub() {//IMyAidlInterface.Stub实际为android.os.Binder 的子类并实现了com.ljp.aidl_server.aidl.IMyAidlInterface接口
            @Override
            public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, String aString) throws RemoteException {
            }
            @Override
            public void addBook(Book book) throws RemoteException {
                synchronized (this) {//同步操作,有可能有多个客户端共同访问
                    if (book != null) {
                        mBookList.add(book);
                    }
                }
            }
            @Override
            public List<Book> getBooks() throws RemoteException {
                return mBookList;
            }
            @Override
            public void setTag(String tag) throws RemoteException {
                synchronized (this) {
                    if (!TextUtils.isEmpty(tag)) {
                        AidlSerVerService.this.tag = tag;
                    }
                }
            }
            @Override
            public String getTag() throws RemoteException {
                return tag;
            }
            @Override
            public void setNum(int num) throws RemoteException {
                synchronized (this) {
                    AidlSerVerService.this.num = num;
                }
            }
            @Override
            public int getNum() throws RemoteException {
                return num;
            }
        };
        @Override
        public IBinder onBind(Intent intent) {
            // TODO: Return the communication channel to the service.
            return stub_binder;
        }
    }
    

    7、在AndroidMainfest文件中注册服务端的Service并对外暴露,至此服务端的代码就编写完成了。

            <!--process:单独为一个进程;enabled:启用;exported:对外暴露 ;
            注:服务端的包名为:com.ljp.aidl_server,客户端绑定Service的时候是使用程序的包名,不是使用AidlSerVerService类的包名  -->
            <service
                android:name=".aidl.AidlSerVerService"
                android:process=":remote"
                android:enabled="true"
                android:exported="true">
                <intent-filter >
                    <action android:name="server.aidl.service.action"/>
                </intent-filter>
            </service>
    

    AIDL通信的客户端

    1、将服务端 main文件夹下的aidl文件夹复制到客户端的main文件夹下,将服务端的Book类复制到客户端的对应包名下,然后Build——>Make Project ;

    image.png

    2、测试调用服务端的AIDL接口进行通信;

    package com.ljp.aidl_client;
    import android.content.ComponentName;
    import android.content.Intent;
    import android.content.ServiceConnection;
    import android.os.Bundle;
    import android.os.IBinder;
    import android.os.RemoteException;
    import android.support.v7.app.AppCompatActivity;
    import android.util.Log;
    import android.view.View;
    import com.ljp.aidl_server.aidl.Book;
    import com.ljp.aidl_server.aidl.IMyAidlInterface;
    import java.util.List;
    public class MainActivity extends AppCompatActivity {
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
        }
        private IMyAidlInterface mService_face;
        private static final String TAG = "Main_Client";
        ServiceConnection mConnection = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                Log.e(TAG, "onServiceConnected: ");
                mService_face = IMyAidlInterface.Stub.asInterface(service);
            }
            @Override
            public void onServiceDisconnected(ComponentName name) {
                Log.e(TAG, "onServiceDisconnected: ");
            }
        };
        public void bindAidlService(View view) {
            Intent intent_service = new Intent();
            intent_service.setPackage("com.ljp.aidl_server"); //设置需要绑定的服务端的包名,不是服务端Service的包名
            intent_service.setAction("server.aidl.service.action");//设置你所需调用服务的意图
            boolean successful = bindService(intent_service, mConnection, BIND_AUTO_CREATE);
            Log.e(TAG, "bindAidlService: successful=" + successful);
        }
        public void UnbindAidlService(View view) {
            if(mConnection!=null){
                unbindService(mConnection);
                Log.e(TAG, "UnbindAidlService: ");
            }
        }
        public void addBook_AidlService(View view) {
            try {
                if (mService_face != null) {
                    mService_face.addBook(new Book(0, "book0", 30.5));
                    Log.e(TAG, "addBook_AidlService: ");
                }
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
        public void getBooks_AidlService(View view) {
            try {
                if (mService_face != null) {
                    List<Book> books = mService_face.getBooks();
                    Log.e(TAG, "addBook_AidlService: books[0]=" + books.get(0));
                }
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
        public void setTag_AidlService(View view) {
            try {
                if (mService_face != null) {
                    mService_face.setTag("setTag_AidlService");
                    Log.e(TAG, "setTag_AidlService: ");
                }
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
        public void getTag_AidlService(View view) {
            try {
                if (mService_face != null) {
                    String tag = mService_face.getTag();
                    Log.e(TAG, "getTag_AidlService: tag=" + tag);
                }
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
        public void setNum_AidlService(View view) {
            try {
                if (mService_face != null) {
                    mService_face.setNum(27);
                    Log.e(TAG, "setNum_AidlService: ");
                }
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
        public void getNum_AidlService(View view) {
            try {
                if (mService_face != null) {
                    int num = mService_face.getNum();
                    Log.e(TAG, "getNum_AidlService: num=" + num);
                }
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
    }
    

    测试结果如下:

    image.png

    IMyAidlInterface.java 文件详解,实际有用的是这个文件,有编写的aidl文件经过编译器自动生成(注:可以单独编写该文件那就不需要aidl文件了)

    package com.ljp.aidl_server.aidl;
    public interface IMyAidlInterface extends android.os.IInterface {
        /**
         * Stub是存根,Proxy是代理,Stub是服务端实现的存根,而Proxy则是Stub的代理。
         * Local-side IPC implementation stub class.
         */
        public static abstract class Stub extends android.os.Binder implements com.ljp.aidl_server.aidl.IMyAidlInterface {
            //Binder的唯一标识,一般使用类名标识
            private static final java.lang.String DESCRIPTOR = "com.ljp.aidl_server.aidl.IMyAidlInterface";
            /**
             * Construct the stub at attach it to the interface.
             */
            public Stub() {
                this.attachInterface(this, DESCRIPTOR);
            }
            /**
             * 将服务端的Binder对象转换为客户端需要的AIDL接口类型的对象,
             * 如果在同一个进程下的话,那么asInterface()将返回服务端的Stub对象本身,因为此时根本不需要跨进称通信,那么直接调用Stub对象的接口就可以了,返回的实现就是服务端的Stub实现,也就是根本没有跨进程通信;
             * 如果不是同一个进程,那么asInterface()返回是Stub.Proxy对象,该对象持有着远程的Binder引用(服务端),因为现在需要跨进程通信,所以如果调用Stub.Proxy的接口的话,那么它们都将是IPC调用,它会通过调用Stub.Proxy的transact方法去与服务端通信
             * Cast an IBinder object into an com.ljp.aidl_server.aidl.IMyAidlInterface interface,generating a proxy if needed.
             *
             * @param obj
             * @return 若位于同一进程中则返回的是服务端的Stub对象本身,否则返回的是系统封装后的Stub.Proxy对象
             */
            public static com.ljp.aidl_server.aidl.IMyAidlInterface asInterface(android.os.IBinder obj) {
                if ((obj == null)) {
                    return null;
                }
                android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
                if (((iin != null) && (iin instanceof com.ljp.aidl_server.aidl.IMyAidlInterface))) {
                    return ((com.ljp.aidl_server.aidl.IMyAidlInterface) iin);
                }
                return new com.ljp.aidl_server.aidl.IMyAidlInterface.Stub.Proxy(obj);
            }
            /**
             * 返回当前的Binder对象,在客户端连接成功时使用:IMyAidlInterface iMyAidlInterface = IMyAidlInterface.Stub.asInterface(service);
             * 检索与此接口相关联的绑定器对象。您必须使用这个而不是普通的cast,这样代理对象才能返回正确的结果。
             *
             * @return
             */
            @Override
            public android.os.IBinder asBinder() {
                return this;
            }
            /**
             * 运行在服务端的Binder线程池中,当客户端发起跨进程请求时,远程请求会通过底层封装后交由此方法处理
             * 默认实现是返回false的存根。您将希望覆盖此操作,以完成事务的适当解组。 如果你想调用这个,调用交易()。
             *
             * @param code
             * @param data
             * @param reply
             * @param flags
             * @return 如果返回false客户端就会请求失败可用作权限验证
             * @throws android.os.RemoteException
             */
            @Override
            public boolean onTransact(int code, android.os.Parcel data, android.os.Parcel reply, int flags) throws android.os.RemoteException {
                switch (code) {
                    case INTERFACE_TRANSACTION: {
                        reply.writeString(DESCRIPTOR);
                        return true;
                    }
                    case TRANSACTION_basicTypes: {
                        data.enforceInterface(DESCRIPTOR);
                        int _arg0;
                        _arg0 = data.readInt();
                        long _arg1;
                        _arg1 = data.readLong();
                        boolean _arg2;
                        _arg2 = (0 != data.readInt());
                        float _arg3;
                        _arg3 = data.readFloat();
                        double _arg4;
                        _arg4 = data.readDouble();
                        java.lang.String _arg5;
                        _arg5 = data.readString();
                        this.basicTypes(_arg0, _arg1, _arg2, _arg3, _arg4, _arg5);
                        reply.writeNoException();
                        return true;
                    }
                    case TRANSACTION_addBook: {
                        data.enforceInterface(DESCRIPTOR);
                        com.ljp.aidl_server.aidl.Book _arg0;
                        if ((0 != data.readInt())) {
                            _arg0 = com.ljp.aidl_server.aidl.Book.CREATOR.createFromParcel(data);//调用Book类中的Parcelable的工厂方法生成一个Book对象,下同
                        } else {
                            _arg0 = null;
                        }
                        this.addBook(_arg0);
                        reply.writeNoException();
                        return true;
                    }
                    case TRANSACTION_getBooks: {
                        data.enforceInterface(DESCRIPTOR);
                        java.util.List<com.ljp.aidl_server.aidl.Book> _result = this.getBooks();
                        reply.writeNoException();
                        reply.writeTypedList(_result);
                        return true;
                    }
                    case TRANSACTION_setTag: {
                        data.enforceInterface(DESCRIPTOR);
                        java.lang.String _arg0;
                        _arg0 = data.readString();
                        this.setTag(_arg0);
                        reply.writeNoException();
                        return true;
                    }
                    case TRANSACTION_getTag: {
                        data.enforceInterface(DESCRIPTOR);
                        java.lang.String _result = this.getTag();
                        reply.writeNoException();
                        reply.writeString(_result);
                        return true;
                    }
                    case TRANSACTION_setNum: {
                        data.enforceInterface(DESCRIPTOR);
                        int _arg0;
                        _arg0 = data.readInt();
                        this.setNum(_arg0);
                        reply.writeNoException();
                        return true;
                    }
                    case TRANSACTION_getNum: {
                        data.enforceInterface(DESCRIPTOR);
                        int _result = this.getNum();
                        reply.writeNoException();
                        reply.writeInt(_result);
                        return true;
                    }
                }
                return super.onTransact(code, data, reply, flags);
            }
            /**
             * 一个运行在客户端的代理,持有服务端的Binder应用
             * Stub是存根,Proxy是代理,Stub是服务端实现的存根,而Proxy则是Stub的代理。
             */
            private static class Proxy implements com.ljp.aidl_server.aidl.IMyAidlInterface {
                private android.os.IBinder mRemote;
                Proxy(android.os.IBinder remote) {
                    mRemote = remote;
                }
                @Override
                public android.os.IBinder asBinder() {
                    return mRemote;
                }
                public java.lang.String getInterfaceDescriptor() {
                    return DESCRIPTOR;
                }
                /**
                 * Demonstrates some basic types that you can use as parameters
                 * and return values in AIDL.
                 */
                @Override
                public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, java.lang.String aString) throws android.os.RemoteException {
                    android.os.Parcel _data = android.os.Parcel.obtain();
                    android.os.Parcel _reply = android.os.Parcel.obtain();
                    try {
                        _data.writeInterfaceToken(DESCRIPTOR);
                        _data.writeInt(anInt);
                        _data.writeLong(aLong);
                        _data.writeInt(((aBoolean) ? (1) : (0)));
                        _data.writeFloat(aFloat);
                        _data.writeDouble(aDouble);
                        _data.writeString(aString);
                        mRemote.transact(Stub.TRANSACTION_basicTypes, _data, _reply, 0);
                        _reply.readException();
                    } finally {
                        _reply.recycle();
                        _data.recycle();
                    }
                }
                @Override
                public void addBook(com.ljp.aidl_server.aidl.Book book) throws android.os.RemoteException {
                    android.os.Parcel _data = android.os.Parcel.obtain();
                    android.os.Parcel _reply = android.os.Parcel.obtain();
                    try {
                        _data.writeInterfaceToken(DESCRIPTOR);
                        if ((book != null)) {
                            _data.writeInt(1);
                            book.writeToParcel(_data, 0);
                        } else {
                            _data.writeInt(0);
                        }
                        mRemote.transact(Stub.TRANSACTION_addBook, _data, _reply, 0);
                        _reply.readException();
                    } finally {
                        _reply.recycle();
                        _data.recycle();
                    }
                }
                @Override
                public java.util.List<com.ljp.aidl_server.aidl.Book> getBooks() throws android.os.RemoteException {
                    android.os.Parcel _data = android.os.Parcel.obtain();
                    android.os.Parcel _reply = android.os.Parcel.obtain();
                    java.util.List<com.ljp.aidl_server.aidl.Book> _result;
                    try {
                        _data.writeInterfaceToken(DESCRIPTOR);
                        mRemote.transact(Stub.TRANSACTION_getBooks, _data, _reply, 0);
                        _reply.readException();
                        _result = _reply.createTypedArrayList(com.ljp.aidl_server.aidl.Book.CREATOR);
                    } finally {
                        _reply.recycle();
                        _data.recycle();
                    }
                    return _result;
                }
                @Override
                public void setTag(java.lang.String tag) throws android.os.RemoteException {
                    android.os.Parcel _data = android.os.Parcel.obtain();
                    android.os.Parcel _reply = android.os.Parcel.obtain();
                    try {
                        _data.writeInterfaceToken(DESCRIPTOR);
                        _data.writeString(tag);
                        mRemote.transact(Stub.TRANSACTION_setTag, _data, _reply, 0);
                        _reply.readException();
                    } finally {
                        _reply.recycle();
                        _data.recycle();
                    }
                }
                @Override
                public java.lang.String getTag() throws android.os.RemoteException {
                    android.os.Parcel _data = android.os.Parcel.obtain();
                    android.os.Parcel _reply = android.os.Parcel.obtain();
                    java.lang.String _result;
                    try {
                        _data.writeInterfaceToken(DESCRIPTOR);
                        mRemote.transact(Stub.TRANSACTION_getTag, _data, _reply, 0);
                        _reply.readException();
                        _result = _reply.readString();
                    } finally {
                        _reply.recycle();
                        _data.recycle();
                    }
                    return _result;
                }
                @Override
                public void setNum(int num) throws android.os.RemoteException {
                    android.os.Parcel _data = android.os.Parcel.obtain();
                    android.os.Parcel _reply = android.os.Parcel.obtain();
                    try {
                        _data.writeInterfaceToken(DESCRIPTOR);
                        _data.writeInt(num);
                        mRemote.transact(Stub.TRANSACTION_setNum, _data, _reply, 0);
                        _reply.readException();
                    } finally {
                        _reply.recycle();
                        _data.recycle();
                    }
                }
                @Override
                public int getNum() throws android.os.RemoteException {
                    android.os.Parcel _data = android.os.Parcel.obtain();
                    android.os.Parcel _reply = android.os.Parcel.obtain();
                    int _result;
                    try {
                        _data.writeInterfaceToken(DESCRIPTOR);
                        mRemote.transact(Stub.TRANSACTION_getNum, _data, _reply, 0);
                        _reply.readException();
                        _result = _reply.readInt();
                    } finally {
                        _reply.recycle();
                        _data.recycle();
                    }
                    return _result;
                }
            }
            //声明binder接口的方法的ID,用于标志方法
            static final int TRANSACTION_basicTypes = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
            static final int TRANSACTION_addBook = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1);
            static final int TRANSACTION_getBooks = (android.os.IBinder.FIRST_CALL_TRANSACTION + 2);
            static final int TRANSACTION_setTag = (android.os.IBinder.FIRST_CALL_TRANSACTION + 3);
            static final int TRANSACTION_getTag = (android.os.IBinder.FIRST_CALL_TRANSACTION + 4);
            static final int TRANSACTION_setNum = (android.os.IBinder.FIRST_CALL_TRANSACTION + 5);
            static final int TRANSACTION_getNum = (android.os.IBinder.FIRST_CALL_TRANSACTION + 6);
        }
        /**
         * Demonstrates some basic types that you can use as parameters
         * and return values in AIDL.
         */
        public void basicTypes(int anInt, long aLong, boolean aBoolean, float aFloat, double aDouble, java.lang.String aString) throws android.os.RemoteException;
        //下面是Binder 通信的接口
        public void addBook(com.ljp.aidl_server.aidl.Book book) throws android.os.RemoteException;
        public java.util.List<com.ljp.aidl_server.aidl.Book> getBooks() throws android.os.RemoteException;
        public void setTag(java.lang.String tag) throws android.os.RemoteException;
        public java.lang.String getTag() throws android.os.RemoteException;
        public void setNum(int num) throws android.os.RemoteException;
        public int getNum() throws android.os.RemoteException;
    }
    

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        在代码下成长:@MiBoy 我也是这段时间温习下进程间通信

      本文标题:Android 的进程间通信 Binder——AIDL的入门使用

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