第二十天使用MediaPlayer+Service+Broadcast完成音乐播放器

1,封装歌曲的类

package com.example.service_music;

/**
 * ${FENG}
 * 2019-07-24
 */
public class Song {
    /** * 歌手 */
    private String singer;
    /** * 歌曲名 */
    private String song;
    /** * 歌曲的地址 */
    private String path;
    /** * 歌曲长度 */
    private int duration;
    /** * 歌曲的大小 */
    private long size;
    /** 当前歌曲的播放位置*/
    private int position;

    public int getPosition() {
        return position;
    }

    public void setPosition(int position) {
        this.position = position;
    }

    public String getSinger() {
        return singer;
    }

    public void setSinger(String singer) {
        this.singer = singer;
    }

    public String getSong() {
        return song;
    }

    public void setSong(String song) {
        this.song = song;
    }

    public String getPath() {
        return path;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public int getDuration() {
        return duration;
    }

    public void setDuration(int duration) {
        this.duration = duration;
    }

    public long getSize() {
        return size;
    }

    public void setSize(long size) {
        this.size = size;
    }

}

2 读取所有的歌曲

package com.example.service_music;

import android.content.Context;
import android.database.Cursor;
import android.provider.MediaStore;
import android.util.Log;
import android.widget.Toast;

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

/**
 * ${FENG}
 * 2019-07-24
 */
public class MusicUtils {
    private static final String TAG = "MusicUtils";

    /**
     * 扫描系统里面的音频文件，返回一个list集合
     */
    public static List<Song> getMusicData(Context context) {
        List<Song> list = new ArrayList<>();
        int i = 0;
        Cursor cursor = context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null, null);
        Log.i(TAG, "getMusicData: "+MediaStore.Audio.Media.EXTERNAL_CONTENT_URI.getPath());
        if (cursor != null) {
            while (cursor.moveToNext()) {
                Song song = new Song();
                song.setSong( cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME)));
                song.setSinger( cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST)));
                song.setPath(cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA)));
                song.setDuration( cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION)));
                song.setSize( cursor.getLong(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE)));
                song.setPosition(i);
                i++;
//                if (song.getSize() > 1000 * 800) {//过滤掉短音频
//                    // 分离出歌曲名和歌手
//                    if (song.getSong().contains("-")) {
//                        String[] str = song.getSong().split("-");
//                        song.setSinger( str[0]);
//                        song.setSong( str[1]);
//                    }
                    list.add(song);
//                }
            }
            // 释放资源
            cursor.close();
        }else{
            Toast.makeText(context, "没有找到文件", Toast.LENGTH_SHORT).show();
            Log.i(TAG, "getMusicData: 没有");
        }
        return list;
    }

    //格式化时间
    public static String formatTime(int time) {
        if (time / 1000 % 60 < 10) {
            return time / 1000 / 60 + ":0" + time / 1000 % 60;
        } else {
            return time / 1000 / 60 + ":" + time / 1000 % 60;
        }
    }
}

3 创建listview布局适配器

package com.example.service_music;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

/**
 * ${FENG}
 * 2019-07-24
 */
public class MyAdapter extends BaseAdapter {
    private Context context;
    private List<Song> list;
    private int position_flag = 0;



    public MyAdapter(MainActivity mainActivity, List<Song> list) {
        this.context = mainActivity;
        this.list = list;
    }

    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int i) {
        return list.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {

        ViewHolder holder = null;
        if (view == null) {
            holder = new ViewHolder();
            // 引入布局
            view = View.inflate(context, R.layout.list_item, null);
            // 实例化对象
            holder.song = (TextView) view.findViewById(R.id.item_mymusic_song);
            holder.singer = (TextView) view
                    .findViewById(R.id.item_mymusic_singer);
            holder.duration = (TextView) view
                    .findViewById(R.id.item_mymusic_duration);
            holder.position = (TextView) view
                    .findViewById(R.id.item_mymusic_postion);

            view.setTag(holder);
        } else {
            holder = (ViewHolder) view.getTag();
        }
        // 给控件赋值
        String string_song = list.get(i).getSong();
        if (string_song.length() >= 5
                && string_song.substring(string_song.length() - 4,
                string_song.length()).equals(".mp3")) {
            holder.song.setText(string_song.substring(0,
                    string_song.length() - 4).trim());
        } else {
            holder.song.setText(string_song.trim());
        }

        holder.singer.setText(list.get(i).getSinger().toString().trim());
        // 时间转换为时分秒
        int duration = list.get(i).getDuration();
        String time = MusicUtils.formatTime(duration);
        holder.duration.setText(time);

        return view;
    }

    class ViewHolder {
        TextView song;// 歌曲名
        TextView singer;// 歌手
        TextView duration;// 时长
        TextView position;// 序号
    }

}

4 service中的代码

package com.example.service_broadcast_music.service;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
import android.widget.RemoteViews;

import com.example.service_broadcast_music.MusicUtils;
import com.example.service_broadcast_music.R;
import com.example.service_broadcast_music.Song;

import java.io.IOException;
import java.util.List;


public class MusicService extends Service {
    private MediaPlayer mediaPlayer;
    private Notification.Builder builder;
    private static final String TAG = "MusicService";
    private List<Song> listSong;
    private int index;
    public MusicService() {
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mediaPlayer = new MediaPlayer();
        listSong = MusicUtils.getMusicData(this);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {

        NotificationManager  manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        builder = new Notification.Builder(this);
        builder.setSmallIcon(R.mipmap.ic_launcher);

        //自定义广播中的布局
        RemoteViews views = new RemoteViews(getPackageName(),R.layout.notifi_layout);

        //第一个按钮的点击逻辑
        /**
         * 通过一个PendingIntent 发送一个intent.
         * getBroadcast的方法是跳往广播的一个intent.
         * getBroadcast的参数,1,上下文,2是请求码唯一即可,3,intent对象,4,PendingIntent的创建方式.
         * setOnClickPendingIntent.这个方法可以给组件设置一个点击事件.参数:1,组件id,2pendingIntent对象
         * 也就是点击以后要跳转到何方.
         */
        Intent intent1 = new Intent();
        intent1.setAction("com.notify.pause");
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this,800,intent1,PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.pause,pendingIntent);

        Intent intent2 = new Intent();
        intent2.setAction("com.notify.restart");
        PendingIntent pendingIntent2 = PendingIntent.getBroadcast(this,810,intent2,PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.restart,pendingIntent2);

        Intent intent3 = new Intent();
        intent1.setAction("com.notify.nav");
        PendingIntent pendingIntent3 = PendingIntent.getBroadcast(this,820,intent1,PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.nav,pendingIntent3);

        Intent intent4 = new Intent();
        intent1.setAction("com.notify.next");
        PendingIntent pendingIntent4 = PendingIntent.getBroadcast(this,830,intent1,PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.next,pendingIntent4);

        //设置通知的布局
        builder.setCustomContentView(views);
        //开始一个前台服务
        startForeground(1,builder.build());
        return super.onStartCommand(intent, flags, startId);
    }

    //中间人对象
    public  class MusicBinder extends Binder{
        public void callPlay(int position){
            playSong(position);
        }
        public void callPause(){
            pause();
        }
        public void callPlayNextSong(){
            //播放下一首
            playNextSong();
        }

        public void callPlayNavSong(){
            //播放上一首
            playNavSong();
        }

        public void callRestart(){
            restart();
        }

    }
    private void restart() {
        mediaPlayer.start();
    }

    private void pause() {
        if(mediaPlayer.isPlaying()){
            mediaPlayer.pause();
        }
    }


    @Override
    public IBinder onBind(Intent intent) {
        return new MusicBinder();
    }

    //播放一个歌曲
    private void playSong(int position) {
        if(mediaPlayer.isPlaying()){
            mediaPlayer.stop();
        }
        //先重置
        mediaPlayer.reset();
        //取到点击歌曲文件的位置
        Song song = listSong.get(position);
        try {
            mediaPlayer.setDataSource(song.getPath());
//            mediaPlayer.prepare();
            mediaPlayer.prepareAsync();
            mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mp) {
                    mediaPlayer.start();
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    private void playNextSong() {
        //防止索引越界
        if(++index > listSong.size()-1){
            index = 0;
        }
        playSong(index);
    }


    //播放上一首
    private void playNavSong() {
       if (--index < 0){
           index = 0;
       }
        playSong(index);
    }

    public void updateNotification(){

    }

}

5 service中通知的布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:orientation="horizontal"
    android:layout_height="match_parent">

   <Button
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:id="@+id/pause"
       android:text="暂停"
       />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/restart"
        android:text="继续播放"
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/nav"
        android:text="上一首"
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/next"
        android:text="下一首"
        />


</LinearLayout>

6 广播的内容

package com.example.service_broadcast_music.broadcast;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

import com.example.service_broadcast_music.MainActivity;

public class MyReceiver extends BroadcastReceiver {
    private static final String TAG = "MyReceiver";

    @Override
    public void onReceive(Context context, Intent intent) {
        String action = intent.getAction();
        Log.i(TAG, "onReceive: "+action);
        /**
         *  通知状态栏里面的广播.
         *  根据通知栏里面广播的类型,来发送一个空消息.
         *  MainActivity接受到消息以后,根据what的值不同,
         *  去调用service里面不同的播放逻辑.
         */
        if (action.equals("com.notify.pause")){
            MainActivity.handler.sendEmptyMessage(110);
        }else if(action.equals("com.notify.restart")){
            MainActivity.handler.sendEmptyMessage(120);
        }else if(action.equals("com.notify.nav")){
            MainActivity.handler.sendEmptyMessage(130);
        }else if(action.equals("com.notify.next")){
            MainActivity.handler.sendEmptyMessage(140);
        }
    }
}

7 MainActivity中的代码

package com.example.service_broadcast_music;

import android.Manifest;
import android.app.Service;
import android.content.ComponentName;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.ServiceConnection;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListView;

import com.example.service_broadcast_music.broadcast.MyReceiver;
import com.example.service_broadcast_music.service.MusicService;

import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private static final String TAG = "MainActivity";
    private ListView lv;
    private Button pause;
    private Button restart;
    private Button nav;
    private Button next;
    private Song song;
    private List<Song> listSong;
    private int index;
    private ServiceConnection connection;

    //注意这个handler就是,广播中用到的handle.是静态的.
    public static Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            Log.i(TAG, "handleMessage:"+msg.what);
            if(msg.what == 110){
                binder.callPause();
            }else if(msg.what == 120){
                binder.callRestart();
            }else if(msg.what == 130){
                binder.callPlayNavSong();
            }else if(msg.what == 140){
                binder.callPlayNextSong();
            }

        }
    };

    public static MusicService.MusicBinder binder;

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

        //初始化所有组件
        initView();

        //动态注册广播
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction("com.notify.pause");
        intentFilter.addAction("com.notify.restart");
        intentFilter.addAction("com.notify.next");
        intentFilter.addAction("com.notify.nav");
        MyReceiver myReceiver = new MyReceiver();
        registerReceiver(myReceiver,intentFilter);

        //请求授权
        requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},100);

        //listview的监听事件
        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Log.i(TAG, "onItemClick: ");
                binder.callPlay(position);
                //根据歌曲的索引来从list中查到歌曲的位置
                index = position;
            }
        });


        //启动服务
        Intent intent = new Intent(this, MusicService.class);
        startService(intent);
        connection = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                binder =  (MusicService.MusicBinder)(service);
            }
            @Override
            public void onServiceDisconnected(ComponentName name) {
            }
        };
        //绑定服务
        bindService(intent,connection, Service.BIND_AUTO_CREATE);
    }


    @Override
    public void onClick(View v) {
        int id = v.getId();
        switch (id){
            case R.id.pause:
                binder.callPause();
                break;
            case R.id.restart:
                binder.callRestart();
                break;
            case R.id.nav:
                binder.callPlayNavSong();
                break;
            case R.id.next:
                if(++index > listSong.size() - 1){
                    index = 0;
                }
                binder.callPlayNextSong();
                break;
        }
    }


    private void initView() {
        lv = findViewById(R.id.lv);
        pause = findViewById(R.id.pause);
        pause.setOnClickListener(this);
        restart = findViewById(R.id.restart);
        restart.setOnClickListener(this);
        nav = findViewById(R.id.nav);
        nav.setOnClickListener(this);
        next = findViewById(R.id.next);
        next.setOnClickListener(this);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if(requestCode == 100 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
           initAdapter();
        }else{
            //结束当前App
            finish();
        }
    }

    //初始化适配器
    public void initAdapter(){
        listSong = MusicUtils.getMusicData(this);
        MyAdapter myAdapter = new MyAdapter(this, listSong);
        lv.setAdapter(myAdapter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (connection != null){
            unbindService(connection);
        }
    }
}

8 MainActivity中的布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/lv"
        android:layout_weight="8"
        android:layout_width="match_parent"
        android:layout_height="0dp">

    </ListView>

    <LinearLayout
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:layout_height="0dp">
        <Button
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:id="@+id/pause"
            android:text="暂停"
            />
        <Button
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:id="@+id/restart"
            android:text="继续播放"
            />
        <Button
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:id="@+id/nav"
            android:text="上一首"
            />
        <Button
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:id="@+id/next"
            android:text="下一首"
            />

    </LinearLayout>


</LinearLayout>

9 listView的布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="60dp"
    android:orientation="horizontal">

    <TextView
        android:id="@+id/item_mymusic_postion"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_alignBottom="@+id/item_mymusic_singer"
        android:layout_gravity="center_vertical"
        android:gravity="center"
        android:layout_margin="10dp"
        android:text="1"
        android:textSize="18sp" />

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="60dp">

        <TextView
            android:id="@+id/item_mymusic_song"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:ellipsize="end"
            android:maxLines="1"
            android:layout_marginRight="10dp"
            android:layout_marginTop="5dp"
            android:text="歌曲名"
            android:textSize="18sp" />

        <TextView
            android:id="@+id/item_mymusic_singer"
            android:layout_width="wrap_content"
            android:layout_height="30dp"
            android:layout_alignParentBottom="true"
            android:layout_alignParentLeft="true"
            android:layout_toLeftOf="@+id/item_mymusic_duration"
            android:gravity="bottom"
            android:text="歌手"
            android:ellipsize="end"
            android:maxLines="1"
            android:layout_marginBottom="5dp"
            android:textSize="16sp" />

        <TextView
            android:id="@+id/item_mymusic_duration"
            android:layout_width="wrap_content"
            android:layout_height="30dp"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:gravity="bottom"
            android:layout_marginRight="5dp"
            android:layout_marginBottom="5dp"
            android:text="歌曲时间"
            android:textSize="16sp" />

    </RelativeLayout>


</LinearLayout>

10 清单文件

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

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

    <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">
        <receiver
            android:name=".broadcast.MyReceiver"
            android:enabled="true"
            android:exported="true"></receiver>

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