Android音频焦点处理服务
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