Android service is explicitly started, implicitly started, bound service, local client calls remote server music files

Project catalog:

app-MainActivity

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    private String otherPackage;

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

        findViewById(R.id.button).setOnClickListener(this);
        findViewById(R.id.button2).setOnClickListener(this);
        findViewById(R.id.button3).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.button:
                otherPackage="com.example.app1";
                break;
            case R.id.button2:
                otherPackage="com.example.app2";
                break;
            case R.id.button3:
                otherPackage="com.example.app3";
                break;
        }
        Intent intent=getPackageManager().getLaunchIntentForPackage(otherPackage);
        if(intent==null){
            Toast.makeText(this, "not this app", Toast.LENGTH_SHORT).show();
        }else{
            startActivity(intent);
        }
    }
}

app1-MainActivity

package com.example.app1;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

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

        findViewById(R.id.button).setOnClickListener(this);
        findViewById(R.id.button2).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Intent intent;
        switch (v.getId()){
            case R.id.button:
                Toast.makeText(this, "play music", Toast.LENGTH_SHORT).show();
                intent=new Intent(MainActivity.this,MyService.class);
                startService(intent);
                findViewById(R.id.button).setEnabled(false);
                findViewById(R.id.button2).setEnabled(true);
                break;
            case R.id.button2:
                Toast.makeText(this, "stop music", Toast.LENGTH_SHORT).show();
                intent=new Intent(MainActivity.this,MyService.class);
                stopService(intent);
                findViewById(R.id.button).setEnabled(true);
                findViewById(R.id.button2).setEnabled(false);
                break;
        }
    }
}

MyService

package com.example.app1;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;

public class MyService extends Service {
    MediaPlayer mp;
    public MyService() {
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mp=MediaPlayer.create(getApplicationContext(),R.raw.cc);
        mp.start();
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mp.stop();
    }
}

app2-MainActivity

package com.example.app2;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

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

        findViewById(R.id.button).setOnClickListener(this);
        findViewById(R.id.button2).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Intent intent;
        switch (v.getId()){
            case R.id.button:
                Toast.makeText(this, "play music", Toast.LENGTH_SHORT).show();
                /*intent=new Intent(MainActivity.this,MyService.class);*/
                intent=new Intent("com.zlm.MAS");
                intent.setPackage("com.example.app2");
                startService(intent);
                findViewById(R.id.button).setEnabled(false);
                findViewById(R.id.button2).setEnabled(true);
                break;
            case R.id.button2:
                Toast.makeText(this, "stop music", Toast.LENGTH_SHORT).show();
                /*intent=new Intent(MainActivity.this,MyService.class);*/
                intent=new Intent("com.zlm.MAS");
                intent.setPackage("com.example.app2");
                stopService(intent);
                findViewById(R.id.button).setEnabled(true);
                findViewById(R.id.button2).setEnabled(false);
                break;
        }
    }
}

MyService

package com.example.app2;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;

public class MyService extends Service {
    MediaPlayer mp;
    public MyService() {
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mp=MediaPlayer.create(getApplicationContext(),R.raw.cc);
        mp.start();
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        throw new UnsupportedOperationException("Not yet implemented");
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mp.stop();
    }
}

Manifestos

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.app2">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name=".MyService" android:enabled="true" android:exported="true">
            <intent-filter>
                <action android:name="com.zlm.MAS"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>
        </service>
    </application>

</manifest>

app3-MainActivity

package com.example.app3;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final ServiceConnection conn=new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                MyService.PlayBinder playBinder= (MyService.PlayBinder) service;
                playBinder.MyMethod();
            }
            @Override
            public void onServiceDisconnected(ComponentName name) {
            }
        };
        Intent intent=new Intent("com.zlm.MPS");
        intent.setPackage("com.example.app3");
        bindService(intent,conn,BIND_AUTO_CREATE);
    }
}

MyService

package com.example.app3;

import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Binder;
import android.os.IBinder;

public class MyService extends Service {
    private MediaPlayer mp;

    public  class PlayBinder extends Binder {
        public  void MyMethod(){
            mp=MediaPlayer.create(getApplicationContext(),R.raw.cc);
            mp.start();
        }
    }
    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        //throw new UnsupportedOperationException("Not yet implemented");
        return  new PlayBinder();
    }
    @Override
    public void onDestroy(){
        if(mp!=null){
            mp.stop();
            mp.release();
        }
        super.onDestroy();
    }
}

Manifestos

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.app3">
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <service
            android:name=".MyService"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="com.zlm.MPS"/>
                <category android:name="android.intent.category.DEFAULT"/>
            </intent-filter>
        </service>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

app4_1-Manifestos

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.app4_1">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <service
            android:name=".MusicPlayService"
            android:enabled="true"
            android:exported="true"
            android:process=":remote">
            <intent-filter>
                <action android:name="com.zlm.MusicService"/>
            </intent-filter>
        </service>

        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MusicPlayService

package com.example.app4_1;
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import android.widget.Toast;

import java.io.IOException;

public class MusicPlayService extends Service {
    private MediaPlayer mPlayer;

    IBinder iBinder = new IRemoteService.Stub() {  
        @Override
        public void play() throws RemoteException {
            if(!mPlayer.isPlaying()){
                mPlayer.start();
            }
        }
        @Override
        public void stop() throws RemoteException {
            if(mPlayer.isPlaying()){
                mPlayer.stop();
                try{
                    mPlayer.prepare();
                }catch (IOException e){
                    e.printStackTrace();
                }
                mPlayer.seekTo(0);
            }
        }
    };
    @Override
    public void onCreate() {
        super.onCreate();
        if(mPlayer==null){
            mPlayer = MediaPlayer.create(this, R.raw.cc);
            mPlayer.setLooping(true);
        }
    }
    @Override
    public IBinder onBind(Intent intent) {  
        Toast.makeText(this, "服务已绑定！", Toast.LENGTH_SHORT).show();
        return iBinder;  
    }
    @Override
    public boolean onUnbind(Intent intent) {
        if (mPlayer!=null){
            mPlayer.stop();
            mPlayer.release();
        }
        return super.onUnbind(intent);
    }
}

IRemoteService.aidl

// IRemoteService.aidl
package com.example.app4_1;

// Declare any non-default types here with import statements

interface IRemoteService {
    /**
     * 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);*/
            void play();
            void stop();
}

app4_2-Manifestos

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.app4_2">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

MainActivity

package com.example.app4_2;

import androidx.appcompat.app.AppCompatActivity;

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.view.View;
import android.widget.Button;

import com.example.app4_1.IRemoteService;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    Button btn1;
    Button btn2;
    //服务端项目包名，需要查看服务端项目清单文件
    public static final String PACKAGE="com.example.app4_1";
    //服务端项目里定义的意图动作名，需要查看服务端项目清单文件
    public static final String ACTION = "com.zlm.MusicService";
    private boolean isBinded=false;
    private IRemoteService mServer;
    private ServiceConnection conn = new ServiceConnection() {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            //建立服务连接时的远程服务代理对象
            mServer = IRemoteService.Stub.asInterface(service);
            isBinded=true;
        }
        @Override
        public void onServiceDisconnected(ComponentName name) {
            isBinded=false;
            mServer=null;
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn1=findViewById(R.id.btn1);btn1.setOnClickListener(this);
        btn2=findViewById(R.id.btn2);btn2.setOnClickListener(this);
        Intent intent = new Intent(ACTION);
        intent.setPackage(PACKAGE); //隐式调用需要指定服务端项目的包名
        bindService(intent,conn,BIND_AUTO_CREATE);
    }
    @Override
    public void onClick(View v) {  //监听器接口方法
        int id = v.getId();
        switch (id){
            case R.id.btn1:
                try {
                    mServer.play();  //调用服务接口方法
                    btn1.setEnabled(false);btn2.setEnabled(true);
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
                break;
            case R.id.btn2:
                try {
                    mServer.stop();   //调用服务接口方法
                    btn2.setEnabled(false);btn1.setEnabled(true);
                } catch (RemoteException e) {
                    e.printStackTrace();
                }
        }
    }
    @Override
    protected void onDestroy() {
        if(isBinded){
            unbindService(conn);  //取消绑定
            mServer = null;
            isBinded=false;
        }
        super.onDestroy();
    }
}

IRemoteService.aidl

// IRemoteService.aidl
package com.example.app4_1;

// Declare any non-default types here with import statements

interface IRemoteService {
    /**
     * 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);*/
            void play();
            void stop();
}