IPC机制之Messenger示例（二）

IPC机制之AIDL传递基础类型数据（一）

IPC机制之AIDL传递Parcelable（三）

IPC机制之AIDL实现客户端回调（四）

Messenger的底层也是通过AIDL实现的，AIDL的讲解网上很多，这里不再祥诉，如果需要查看AIDL的示例可以查看我的前一篇文章
IPC机制之AIDL示例

下面我们直接上Messenger跨进程通信的 代码

Client#MainActivity.java

package com.messenger.wzf.clientmodule;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

import java.text.SimpleDateFormat;

public class MainActivity extends AppCompatActivity {

    private Messenger serverMessenger;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void startService(View view) {
        Intent intent = new Intent();
        intent.setClassName("com.messenger.wzf.messengersample", "com.messenger.wzf.messengersample.IPCService");
        bindService(intent, conn, BIND_AUTO_CREATE);
    }

    private ServiceConnection conn = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            serverMessenger = new Messenger(service);
            communicate();
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            serverMessenger = null;
        }
    };

    private void communicate() {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Message message = Message.obtain();
        Bundle msg = new Bundle();
        msg.putInt("message", 1);
        message.setData(msg);
        Log.i("info", "客户端发送消息1");
        message.what = 1;
        message.replyTo = messenger;
        if (serverMessenger != null) {
            try {
                serverMessenger.send(message);
            } catch (RemoteException e) {
                e.printStackTrace();
            }
        }
    }

    private Messenger messenger = new Messenger(new Handler() {
        @Override
        public void handleMessage(Message msg) {
            int a = msg.getData().getInt("message");
            Log.i("info", "客户端接收消息" + ++a);
            Message message = Message.obtain();
            Bundle bundle = new Bundle();
            bundle.putInt("message", ++a);
            message.setData(bundle);
            Log.i("info", "客户端发送消息" + a);
            message.what = 2;
            if (serverMessenger != null) {
                try {
                    serverMessenger.send(message);
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
            }
        }
    });

    @Override
    protected void onDestroy() {
        unbindService(conn);
        super.onDestroy();
    }
}

Server#IPCService.java

package com.messenger.wzf.messengersample;

import android.app.Service;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.support.annotation.Nullable;
import android.util.Log;

public class IPCService extends Service {

    private Messenger messenger = new Messenger(new Handler() {
        @Override
        public void handleMessage(Message msg) {
            int a = msg.getData().getInt("message");
            switch (msg.what) {
                case 1:
                    Log.i("info", "服务器接收消息" + ++a);
                    Messenger client = msg.replyTo;
                    if (client != null) {
                        Message reply = Message.obtain();
                        Bundle message = new Bundle();
                        message.putInt("message", ++a);
                        Log.i("info", "服务器发送消息" + a);
                        reply.setData(message);
                        try {
                            client.send(reply);
                        } catch (RemoteException e) {
                            e.printStackTrace();
                        }
                    }
                    break;
                case 2:
                    Log.i("info", "服务器接收消息" + ++a);
                    break;
            }
        }
    });

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return messenger.getBinder();
    }
}

Server#AndroidManifest

 <service
     android:name=".IPCService"
     android:exported="true" />

注意：

1. 服务端和客户端是2个Module，分别运行在不同进程中；
2. 服务端需要启动程序，但是不需要启动IPCService，可以由客户端去调用bindService的时候来启动IPCService。

源码下载