1. 服务代码：

package com.rmicro.audiofocus;

import java.io.IOException;

import android.app.Service;

import android.content.Intent;

import android.media.AudioManager;

import android.media.AudioManager.OnAudioFocusChangeListener;

import android.media.MediaPlayer.OnPreparedListener;

import android.media.MediaPlayer;

import android.os.Bundle;

import android.os.IBinder;

import android.os.PowerManager;

import android.util.Log;

public class MusicService extends Service {

private AudioManager mAm;

private boolean isPlaymusic;

private String url;

private MediaPlayer mediaPlayer;

private static final int AUDIO_STREAM_TYPE = AudioManager.STREAM_MUSIC;

private static final int REQUEST_AUDIO_FOCUS_TYPE = AudioManager.AUDIOFOCUS_GAIN;

private int mAudioStatus = AUDIO_STATUS_IDLE;

public static final int AUDIO_STATUS_IDLE = 0;

public static final int AUDIO_STATUS_INITIALIZED = 1;

public static final int AUDIO_STATUS_PREPARING = 2;

public static final int AUDIO_STATUS_PREPARED = 3;

public static final int AUDIO_STATUS_STARTED = 4;

public static final int AUDIO_STATUS_PAUSED = 5;

public static final int AUDIO_STATUS_PLAYBACKCOMPLETED = 6;

public static final int AUDIO_STATUS_STOPED = 7;

private static final String TAG = "leo";

@Override

public void onCreate() {

super.onCreate();

mAm = (AudioManager) getSystemService(AUDIO_SERVICE);

}

@Override

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

// TODO Auto-generated method stub

if (intent != null) {

Bundle bundle = intent.getExtras();

if (bundle != null) {

isPlaymusic = bundle.getBoolean("isPlay", true);

url = bundle.getString("url");

if (isPlaymusic)

{

playAudio();

}

else

{

stopAudio();

// pauseAudio();

}

}

}

return super.onStartCommand(intent, flags, startId);

}

OnAudioFocusChangeListener afChangeListener = new OnAudioFocusChangeListener() {

public void onAudioFocusChange(int focusChange) {

Log.i(TAG, "onAudioFocusChange...");

dump();

if (focusChange == AudioManager.AUDIOFOCUS_GAIN) {

// 获得音频焦点

// Resume playback

startAudio();

}

else if (focusChange == AudioManager.AUDIOFOCUS_LOSS) {

// 长久的失去音频焦点，释放MediaPlayer

mAm.abandonAudioFocus(afChangeListener);

// Stop playback

stopAudio();

}

else if (focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT) {

// 暂时失去音频焦点，暂停播放等待重新获得音频焦点

// Pause playback

pauseAudio();

}

else if(focusChange == AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK)

{

// 失去音频焦点，无需停止播放，降低声音即可也可以暂停播放。

// lowerAudioVolume();

pauseAudio();

}

}

};

private boolean requestFocus() {

// Request audio focus for playback

int result = mAm.requestAudioFocus(afChangeListener,

// Use the music stream.

AUDIO_STREAM_TYPE,

// Request permanent focus.

REQUEST_AUDIO_FOCUS_TYPE);

Log.i("leo", "result="+result);

return result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED;

}

private void lowerAudioVolume()

{

Log.i(TAG, "lowerAudioVolume...");

dump();

if(mAudioStatus == AUDIO_STATUS_STARTED)

{

if (mediaPlayer != null) {

mediaPlayer.setVolume(0.1f, 0.1f);

}

}

}

MediaPlayer.OnCompletionListener completionListener = new MediaPlayer.OnCompletionListener() {

@Override

public void onCompletion(MediaPlayer player) {

if(!player.isLooping()){

mAm.abandonAudioFocus(afChangeListener);

mAudioStatus = AUDIO_STATUS_PLAYBACKCOMPLETED;

}

}

};

private void playAudio() {

Log.i(TAG, "playAudio...");

dump();

if (requestFocus()) {

if (mAudioStatus == AUDIO_STATUS_IDLE) {

Log.i("leo", "url="+url);

mediaPlayer = new MediaPlayer();

// mediaPlayer.reset();

// mAudioStatus = AUDIO_STATUS_IDLE;

// 设置音频流的类型

mediaPlayer.setAudioStreamType(AUDIO_STREAM_TYPE);

// 设置播放完成监听

mediaPlayer.setOnCompletionListener(completionListener);

//设定CUP锁定

mediaPlayer.setWakeMode(getApplicationContext(),

PowerManager.PARTIAL_WAKE_LOCK);

try {

mediaPlayer.setDataSource(url);

} catch (IllegalArgumentException e) {

// TODO Auto-generated catch block

e.printStackTrace();

Log.i(TAG, "set data source error");

} catch (SecurityException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IllegalStateException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

mAudioStatus = AUDIO_STATUS_INITIALIZED;

// 设置文件装载监听

mediaPlayer.setOnPreparedListener(new OnPreparedListener() {

@Override

public void onPrepared(MediaPlayer mp) {

// 装载完毕 开始播放流媒体

mAudioStatus = AUDIO_STATUS_PREPARED;

startAudio();

}

});

}

if(mAudioStatus == AUDIO_STATUS_INITIALIZED

|| mAudioStatus == AUDIO_STATUS_STOPED )

{

//通过同步的方式装载媒体资源

//mediaPlayer.prepare();

//mAudioStatus = AUDIO_STATUS_PREPARED;

// 通过异步的方式装载媒体资源

mediaPlayer.prepareAsync();

mAudioStatus = AUDIO_STATUS_PREPARING;

}

startAudio();

}

}

@Override

public void onDestroy() {

super.onDestroy();

releaseAudio();

}

@Override

public IBinder onBind(Intent arg0) {

// TODO Auto-generated method stub

return null;

}

private void dump()

{

Log.i(TAG, "current audio status is = "+audioStatusToString());

}

private String audioStatusToString()

{

switch(mAudioStatus)

{

case AUDIO_STATUS_IDLE:

return "audio_idle";

case AUDIO_STATUS_INITIALIZED:

return "audio_initialized";

case AUDIO_STATUS_PREPARING:

return "audio_preparing";

case AUDIO_STATUS_PREPARED:

return "audio_prepared";

case AUDIO_STATUS_STARTED:

return "audio_started";

case AUDIO_STATUS_PAUSED:

return "audio_paused";

case AUDIO_STATUS_PLAYBACKCOMPLETED:

return "audio_playbackcompleted";

case AUDIO_STATUS_STOPED:

return "audio_stoped";

}

return "audio_null";

}

private void startAudio()

{

Log.i(TAG, "startAudio...");

dump();

if(mAudioStatus == AUDIO_STATUS_PAUSED

|| mAudioStatus == AUDIO_STATUS_PREPARED

|| mAudioStatus == AUDIO_STATUS_PLAYBACKCOMPLETED)

{

if (mediaPlayer != null) {

mediaPlayer.start();

mAudioStatus = AUDIO_STATUS_STARTED;

// 还原音量

mediaPlayer.setVolume(1.0f, 1.0f);

}

}

}

private void pauseAudio() {

Log.i(TAG, "pauseAudio...");

dump();

if(mAudioStatus == AUDIO_STATUS_STARTED)

{

if (mediaPlayer != null && mediaPlayer.isPlaying()) {

mediaPlayer.pause();

mAudioStatus = AUDIO_STATUS_PAUSED;

}

}

else

{

Log.i("leo", "resumeAudio error, current audio status = "+mAudioStatus);

}

}

private void stopAudio() {

Log.i(TAG, "stopAudio...");

dump();

if(mAudioStatus == AUDIO_STATUS_PREPARED

|| mAudioStatus == AUDIO_STATUS_STARTED

|| mAudioStatus == AUDIO_STATUS_PAUSED

|| mAudioStatus == AUDIO_STATUS_PLAYBACKCOMPLETED )

{

if (mediaPlayer != null) {

mediaPlayer.stop();

mAudioStatus = AUDIO_STATUS_STOPED;

}

}

}

private void releaseAudio()

{

Log.i(TAG, "releaseAudio...");

dump();

mAm.abandonAudioFocus(afChangeListener);

if (mediaPlayer != null)

{

mediaPlayer.release();

mAudioStatus = AUDIO_STATUS_IDLE;

mediaPlayer = null;

}

}

}

2. AndroidManifest.xml配置

添加服务