Android MediaPlayer音频播放器封装示例浅析

public class SimpleAudioPlayer {
    private static SimpleAudioPlayer sInstance;
    private MediaPlayer mMediaPlayer;
    private Context mContext;
    private boolean mIsPrepared = false;
    private int mDuration; // 音频总时长
    private int mCurPosition; // 当前播放位置
    private OnStateChangeListener mOnStateChangeListener;
    private OnErrorListener mOnErrorListener;
    // 单例模式
    public static SimpleAudioPlayer getInstance(Context context) {
        if (sInstance == null) {
            synchronized (SimpleAudioPlayer.class) {
                if (sInstance == null) {
                    sInstance = new SimpleAudioPlayer(context.getApplicationContext());
                }
            }
        }
        return sInstance;
    }
    private SimpleAudioPlayer(Context context) {
        mContext = context;
        mMediaPlayer = new MediaPlayer();
        mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(MediaPlayer mp) {
                mIsPrepared = true;
                mDuration = mp.getDuration();
                if (mOnStateChangeListener != null) {
                    mOnStateChangeListener.onPrepared();
                }
            }
        });
        mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mp) {
                if (mOnStateChangeListener != null) {
                    mOnStateChangeListener.onComplete();
                }
            }
        });
        mMediaPlayer.setOnErrorListener(new MediaPlayer.OnErrorListener() {
            @Override
            public boolean onError(MediaPlayer mp, int what, int extra) {
                mIsPrepared = false;
                if (mOnErrorListener != null) {
                    mOnErrorListener.onError(what, extra);
                }
                return false;
            }
        });
        mMediaPlayer.setOnSeekCompleteListener(new MediaPlayer.OnSeekCompleteListener() {
            @Override
            public void onSeekComplete(MediaPlayer mp) {
                if (mOnStateChangeListener != null) {
                    mOnStateChangeListener.onSeekComplete();
                }
            }
        });
    }
    public void setOnStateChangeListener(OnStateChangeListener listener) {
        mOnStateChangeListener = listener;
    }
    public void setOnErrorListener(OnErrorListener listener) {
        mOnErrorListener = listener;
    }
    public void play(String url) {
        if (TextUtils.isEmpty(url)) {
            return;
        }
        if (!NetworkUtil.isConnected(mContext)) { // 检查网络状态
            if (mOnErrorListener != null) {
                mOnErrorListener.onError(ERROR_NETWORK_DISCONNECTED, "Network disconnected");
            }
            return;
        }
        try {
            mMediaPlayer.reset();
            mMediaPlayer.setDataSource(url);
            mMediaPlayer.prepareAsync();
        } catch (IOException e) {
            e.printStackTrace();
            mIsPrepared = false;
        }
    }
    public void pause() {
        if (mMediaPlayer.isPlaying()) {
            mMediaPlayer.pause();
            if (mOnStateChangeListener != null) {
                mOnStateChangeListener.onPause();
            }
        }
    }
    public void resume() {
        if (mIsPrepared && !mMediaPlayer.isPlaying()) {
            mMediaPlayer.start();
            if (mOnStateChangeListener != null) {
                mOnStateChangeListener.onResume();
            }
        }
    }
    public void stop() {
        if (mMediaPlayer.isPlaying() || mIsPrepared) {
            mMediaPlayer.stop();
            mIsPrepared = false;
            if (mOnStateChangeListener != null) {
                mOnStateChangeListener.onStop();
            }
        }
    }

SimpleAudioPlayer player = SimpleAudioPlayer.getInstance(context);