序列化和反序列化

把对象转换为字节序列的过程称为对象的序列化。把字节序列恢复为对象的过程称为对象的反序列化。简单说就是为了保存在内存中的各种对象的状态，并且可以把保存的对象状态再读出来。

当两个进程在进行远程通信时，彼此可以发送各种类型的数据。无论是何种类型的数据，都会以二进制序列的形式在网络上传送。发送方需要把这个Java对象转换为字节序列，才能在网络上传送；接收方则需要把字节序列再恢复为Java对象。

在 JADE开发过程中， Agent 之间的通信的消息主要有三种：String, Java Serializable Object, Ontology Object.

JADE 发送/接收基于Java序列化对象,一般需要如下几个操作：

定义一个类
实现 Serializable接口
ACLMessage 的 setContentObject() 方法设置发送内容
ACLMessage 的 getContentObject() 方法接收内容

简单示例

创建一个 Human 类

package cn.bcrab.agent;

import java.io.Serializable;

public class Human implements Serializable {

    String name;
    int age;
    String gender;

    Human(String name, int age, String gender){
        this.name = name;
        this.age = age;
        this.gender = gender;
    }

    public String toString(){
        return "name: "+ name + "age: " + age + "gender: " + gender;
    }

}

发送类 Sender.java

package cn.bcrab.agent;

import jade.core.AID;
import jade.core.Agent;
import jade.lang.acl.ACLMessage;

import java.io.IOException;

public class Sender extends Agent {

    @Override
    protected void setup() {
        try {
            ACLMessage msg = new ACLMessage(ACLMessage.INFORM);
            msg.setContent("hello world");
            AID a = new AID("Receiver", AID.ISLOCALNAME);
            msg.addReceiver(a);
            Human human = new Human("Bruce", 18, "Man");
            msg.setContentObject(human);
            msg.setLanguage("JavaSerialization");
            send(msg);
            
        } catch (IOException e) {
            e.printStackTrace();
        }
        doDelete();
    }
}

接收类 Receiver.java

package cn.bcrab.agent;

import jade.core.Agent;
import jade.core.behaviours.CyclicBehaviour;
import jade.lang.acl.ACLMessage;
import jade.lang.acl.UnreadableException;

public class Receiver extends Agent{
    @Override
    protected void setup() {

        addBehaviour(new CyclicBehaviour(this) {
            @Override
            public void action() {
                try {
                    ACLMessage msg = blockingReceive();
                    System.out.println(getLocalName() + " receive msg :" + msg);
                    if ("JavaSerialization".equals(msg.getLanguage())){
                        Human human = (Human)msg.getContentObject();
                        System.out.println(getLocalName() + " 获取Java对象");
                        System.out.println(human.getClass().getName());
                        System.out.println(human.toString());
                    }
                }catch (UnreadableException e) {
                    System.err.println(getLocalName() + " catched exception " + e.getMessage());
                }
                block();
            }
        });
    }
}

先启动 Receiver, 再启动Sender。
运行结果：

Receiver receive msg :(INFORM
 :sender  ( agent-identifier :name a@Platform  :addresses (sequence http://DESKTOP-KQ727CJ:7778/acc ))
 :receiver  (set ( agent-identifier :name Receiver@Platform ) )
:X-JADE-Encoding Base64
 :content  "rO0ABXNyABRjbi5iY3JhYi5hZ2VudC5IdW1hbuz3L9Sc9EeXAgADSQADYWdlTAAGZ2VuZGVydAASTGphdmEvbGFuZy9TdHJpbmc7TAAEbmFtZXEAfgABeHAAAAASdAADTWFudAAFQnJ1Y2U=" 
 :language  JavaSerialization )
Receiver 获取Java对象
cn.bcrab.agent.Human
name: Bruceage: 18gender: Man