Question

我正在使用MediaPlayer类开发App流音频。查看应用截图，我在这里做错了什么？请查看

package musicplayer.androidhive.com.musicplayer;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Random;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidBuildingMusicPlayerActivity extends Activity implements OnCompletionListener, SeekBar.OnSeekBarChangeListener {

private ImageButton btnPlay;
private ImageButton btnForward;
private ImageButton btnBackward;
private ImageButton btnNext;
private ImageButton btnPrevious;
private ImageButton btnPlaylist;
private ImageButton btnRepeat;
private ImageButton btnShuffle;
private SeekBar songProgressBar;
private TextView songTitleLabel;
private TextView songCurrentDurationLabel;
private TextView songTotalDurationLabel;
// Media Player
private  MediaPlayer mp;
// Handler to update UI timer, progress bar etc,.
private Handler mHandler = new Handler();;
private SongsManager songManager;
private Utilities utils;
private int seekForwardTime = 5000; // 5000 milliseconds
private int seekBackwardTime = 5000; // 5000 milliseconds
private int currentSongIndex = 0; 
private boolean isShuffle = false;
private boolean isRepeat = false;
private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();
Context thisActivity;


@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.player);

thisActivity = this;
// All player buttons
btnPlay = (ImageButton) findViewById(R.id.btnPlay);
btnForward = (ImageButton) findViewById(R.id.btnForward);
btnBackward = (ImageButton) findViewById(R.id.btnBackward);
btnNext = (ImageButton) findViewById(R.id.btnNext);
btnPrevious = (ImageButton) findViewById(R.id.btnPrevious);
btnPlaylist = (ImageButton) findViewById(R.id.btnPlaylist);
btnRepeat = (ImageButton) findViewById(R.id.btnRepeat);
btnShuffle = (ImageButton) findViewById(R.id.btnShuffle);
songProgressBar = (SeekBar) findViewById(R.id.songProgressBar);
songTitleLabel = (TextView) findViewById(R.id.songTitle);
songCurrentDurationLabel = (TextView) findViewById(R.id.songCurrentDurationLabel);
songTotalDurationLabel = (TextView) findViewById(R.id.songTotalDurationLabel);

// Mediaplayer
mp = new MediaPlayer();
songManager = new SongsManager();
utils = new Utilities();

// Listeners
songProgressBar.setOnSeekBarChangeListener(this); // Important
mp.setOnCompletionListener(this); // Important

// Getting all songs list
songsList = songManager.getPlayList();

// By default play first song
playSong(0);

/**
* Play button click event
* plays a song and changes button to pause image
* pauses a song and changes button to play image
* */
btnPlay.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// check for already playing
if(mp.isPlaying()){
if(mp!=null){
mp.pause();
// Changing button image to play button
btnPlay.setImageResource(R.drawable.btn_play);
}
}else{
// Resume song
if(mp!=null){

try{

mp.setDataSource(thisActivity,Uri.parse("http://208.109.189.86/files/song.mp3"));
mp.start();
// Changing button image to pause button
btnPlay.setImageResource(R.drawable.btn_pause);

} catch (Exception ex){

Log.e("MYAPP", "exception", ex);

}
}
}

}
});

/**
* Forward button click event
* Forwards song specified seconds
* */
btnForward.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// get current song position                
int currentPosition = mp.getCurrentPosition();
// check if seekForward time is lesser than song duration
if(currentPosition + seekForwardTime <= mp.getDuration()){
// forward song
mp.seekTo(currentPosition + seekForwardTime);
}else{
// forward to end position
mp.seekTo(mp.getDuration());
}
}
});

/**
* Backward button click event
* Backward song to specified seconds
* */
btnBackward.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// get current song position                
int currentPosition = mp.getCurrentPosition();
// check if seekBackward time is greater than 0 sec
if(currentPosition - seekBackwardTime >= 0){
// forward song
mp.seekTo(currentPosition - seekBackwardTime);
}else{
// backward to starting position
mp.seekTo(0);
}

}
});

/**
* Next button click event
* Plays next song by taking currentSongIndex + 1
* */
btnNext.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
// check if next song is there or not
if(currentSongIndex < (songsList.size() - 1)){
playSong(currentSongIndex + 1);
currentSongIndex = currentSongIndex + 1;
}else{
// play first song
playSong(0);
currentSongIndex = 0;
}

}
});

/**
* Back button click event
* Plays previous song by currentSongIndex - 1
* */
btnPrevious.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
if(currentSongIndex > 0){
playSong(currentSongIndex - 1);
currentSongIndex = currentSongIndex - 1;
}else{
// play last song
playSong(songsList.size() - 1);
currentSongIndex = songsList.size() - 1;
}

}
});

/**
* Button Click event for Repeat button
* Enables repeat flag to true
* */
btnRepeat.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
if(isRepeat){
isRepeat = false;
Toast.makeText(getApplicationContext(), "Repeat is OFF", Toast.LENGTH_SHORT).show();
btnRepeat.setImageResource(R.drawable.btn_repeat);
}else{
// make repeat to true
isRepeat = true;
Toast.makeText(getApplicationContext(), "Repeat is ON", Toast.LENGTH_SHORT).show();
// make shuffle to false
isShuffle = false;
btnRepeat.setImageResource(R.drawable.btn_repeat_focused);
btnShuffle.setImageResource(R.drawable.btn_shuffle);
}   
}
});

/**
* Button Click event for Shuffle button
* Enables shuffle flag to true
* */
btnShuffle.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
if(isShuffle){
isShuffle = false;
Toast.makeText(getApplicationContext(), "Shuffle is OFF", Toast.LENGTH_SHORT).show();
btnShuffle.setImageResource(R.drawable.btn_shuffle);
}else{
// make repeat to true
isShuffle= true;
Toast.makeText(getApplicationContext(), "Shuffle is ON", Toast.LENGTH_SHORT).show();
// make shuffle to false
isRepeat = false;
btnShuffle.setImageResource(R.drawable.btn_shuffle_focused);
btnRepeat.setImageResource(R.drawable.btn_repeat);
}   
}
});

/**
* Button Click event for Play list click event
* Launches list activity which displays list of songs
* */
btnPlaylist.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
Intent i = new Intent(getApplicationContext(), PlayListActivity.class);
startActivityForResult(i, 100);         
}
});

}

/**
* Receiving song index from playlist view
* and play the song
* */
@Override
protected void onActivityResult(int requestCode,
         int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == 100){
currentSongIndex = data.getExtras().getInt("songIndex");
// play selected song
playSong(currentSongIndex);
}

}

/**
* Function to play a song
* @param songIndex - index of song
* */
public void  playSong(int songIndex){
// Play song
try {
mp.reset();
//mp.setDataSource(songsList.get(songIndex).get("songPath"));
String AudioFile = "http://208.109.189.86/files/song.mp3";
mp.setDataSource(this, Uri.parse(AudioFile));
mp.prepare();
mp.start();
// Displaying Song title
String songTitle = songsList.get(songIndex).get("songTitle");
songTitleLabel.setText(songTitle);

// Changing Button Image to pause image
btnPlay.setImageResource(R.drawable.btn_pause);

// set Progress bar values
songProgressBar.setProgress(0);
songProgressBar.setMax(100);

// Updating progress bar
updateProgressBar();            
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

/**
* Update timer on seekbar
* */
public void updateProgressBar() {
mHandler.postDelayed(mUpdateTimeTask, 100);        
}   

/**
* Background Runnable thread
* */
private Runnable mUpdateTimeTask = new Runnable() {
public void run() {
long totalDuration = mp.getDuration();
long currentDuration = mp.getCurrentPosition();

// Displaying Total Duration time
songTotalDurationLabel.setText(""+utils.milliSecondsToTimer(totalDuration));
// Displaying time completed playing
songCurrentDurationLabel.setText(""+utils.milliSecondsToTimer(currentDuration));

// Updating progress bar
int progress = (int)(utils.getProgressPercentage(currentDuration, totalDuration));
//Log.d("Progress", ""+progress);
songProgressBar.setProgress(progress);

// Running this thread after 100 milliseconds
mHandler.postDelayed(this, 100);
}
};

/**
* 
* */
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromTouch) {

}

/**
* When user starts moving the progress handler
* */
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// remove message Handler from updating progress bar
mHandler.removeCallbacks(mUpdateTimeTask);
}

/**
* When user stops moving the progress hanlder
* */
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
mHandler.removeCallbacks(mUpdateTimeTask);
int totalDuration = mp.getDuration();
int currentPosition = utils.progressToTimer(seekBar.getProgress(), totalDuration);

// forward or backward to certain seconds
mp.seekTo(currentPosition);

// update timer progress again
updateProgressBar();
}

/**
* On Song Playing completed
* if repeat is ON play same song again
* if shuffle is ON play random song
* */
@Override
public void onCompletion(MediaPlayer arg0) {

// check for repeat is ON or OFF
if(isRepeat){
// repeat is on play same song again
playSong(currentSongIndex);
} else if(isShuffle){
// shuffle is on - play a random song
Random rand = new Random();
currentSongIndex = rand.nextInt((songsList.size() - 1) - 0 + 1) + 0;
playSong(currentSongIndex);
} else{
// no repeat or shuffle ON - play next song
if(currentSongIndex < (songsList.size() - 1)){
playSong(currentSongIndex + 1);
currentSongIndex = currentSongIndex + 1;
}else{
// play first song
playSong(0);
currentSongIndex = 0;
}
}
}

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

}

异常屏幕截图： here

我尝试了setDataSource。

mediaPlayer.setDataSource（this，Uri.parse（myURL））;

我不知道这里出了什么问题。当我调用set数据源时，它会抛出错误。在logcat中，我可以看到像

这样的消息

D / MediaPlayer：无法在客户端打开文件，尝试服务器端

主要活动代码截图： here

我在清单中设置了互联网权限。

Answer 1

尝试使用MediaPlayer.create（），您也可能只想在玩家实际准备就绪后启动，例如：

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    MediaPlayer player = MediaPlayer.create(this, Uri.parse("http://www.urltofile.com/file.mp3"));
    player.setOnPreparedListener(new OnPreparedListener() { 
        @Override
        public void onPrepared(MediaPlayer mp) {
            mp.start();
        }
    });
}

Answer 2

您可以尝试这样做

MediaPlayer mp = new MediaPlayer(/*Your-Context*/);
mp.setDataSource(/*MP3 file's Url*/);
mp.setOnPreparedListener(new OnPreparedListener(){
    onPrepared(MediaPlayer mp){
        mp.start();
    }
});
mp.prepareAsync();

无法在android FileNotFoundException中创建媒体播放器

2 个答案: