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几天来,我一直在尝试为我在 android 上运行的 4.x 版本的应用程序流式音频找到解决方案,但没有找到。我认为这个类与我需要的应用程序非常相似。但不幸的是我是这门编程语言的初学者,很难找到解决方案,所以我请求帮助我使用这个类。

package com.testestreaming;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.content.Context;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.ProgressBar;
import android.widget.TextView;

/**
 * MediaPlayer does not yet support streaming from external URLs so this class provides a pseudo-streaming function
 * by downloading the content incrementally & playing as soon as we get enough audio in our temporary storage.
 */
public class MainActivity extends Activity {

    private static final int INTIAL_KB_BUFFER =  96*10/8;//assume 96kbps*10secs/8bits per byte
    private TextView textStreamed;
    private ImageButton playButton;
    private ProgressBar progressBar;

    //  Track for display by progressBar
    private long mediaLengthInKb, mediaLengthInSeconds;
    private int totalKbRead = 0;

    // Create Handler to call View updates on the main UI thread.
    private final Handler handler = new Handler();
    private MediaPlayer mediaPlayer;
    private File downloadingMediaFile;
    private boolean isInterrupted;
    private Context context;
    private int counter = 0;

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void StreamingMediaPlayer(Context context, TextView textStreamed, ImageButton    playButton, Button streamButton, ProgressBar progressBar){
        this.context = context;
        this.textStreamed = textStreamed;
        this.playButton = playButton;
        this.progressBar = progressBar;
    }

    /*
    Progressivly download the media to a temporary location and update the MediaPlayer as new content becomes available.
    */
    public void startStreaming(final String mediaUrl, long mediaLengthInKb, long mediaLengthInSeconds) throws IOException {

        this.mediaLengthInKb = mediaLengthInKb;
        this.mediaLengthInSeconds = mediaLengthInSeconds;

        Runnable r = new Runnable() {   
            public void run() {   
                try {   
                    downloadAudioIncrement(mediaUrl);
                } catch (IOException e) {
                    Log.e(getClass().getName(), "Unable to initialize the MediaPlayer for fileUrl=" + mediaUrl, e);
                    return;
                }   
            }   
        };
        new Thread(r).start();
    }

    /**  
     * Download the url stream to a temporary location and then call the setDataSource  
     * for that local file
     */  
    public void downloadAudioIncrement(String mediaUrl) throws IOException {

        URLConnection cn = new URL(mediaUrl).openConnection();   
        cn.connect();   
        InputStream stream = cn.getInputStream();
        if (stream == null) {
            Log.e(getClass().getName(), "Unable to create InputStream for mediaUrl:" + mediaUrl);
        }

        downloadingMediaFile = new File(context.getCacheDir(),"downloadingMedia.dat");

        // Just in case a prior deletion failed because our code crashed or something, we also delete any previously 
        // downloaded file to ensure we start fresh.  If you use this code, always delete 
        // no longer used downloads else you'll quickly fill up your hard disk memory.  Of course, you can also 
        // store any previously downloaded file in a separate data cache for instant replay if you wanted as well.
        if (downloadingMediaFile.exists()) {
            downloadingMediaFile.delete();
        }

        @SuppressWarnings("resource")
        FileOutputStream out = new FileOutputStream(downloadingMediaFile);   
        byte buf[] = new byte[16384];
        int totalBytesRead = 0, incrementalBytesRead = 0;
        do {
            int numread = stream.read(buf);   
            if (numread <= 0)   
                break;   
            out.write(buf, 0, numread);
            totalBytesRead += numread;
            incrementalBytesRead += numread;
            totalKbRead = totalBytesRead/1000;

            testMediaBuffer();
            fireDataLoadUpdate();
        } while (validateNotInterrupted());   
            stream.close();
        if (validateNotInterrupted()) {
            fireDataFullyLoaded();
        }
    }  

    private boolean validateNotInterrupted() {
        if (isInterrupted) {
            if (mediaPlayer != null) {
                mediaPlayer.pause();
                //mediaPlayer.release();
            }
            return false;
        } else {
            return true;
        }
    }


    /**
     * Test whether we need to transfer buffered data to the MediaPlayer.
     * Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
     */  
    private void  testMediaBuffer() {
        Runnable updater = new Runnable() {
            public void run() {
                if (mediaPlayer == null) {
                    //  Only create the MediaPlayer once we have the minimum buffered data
                    if ( totalKbRead >= INTIAL_KB_BUFFER) {
                        try {
                            startMediaPlayer();
                        } catch (Exception e) {
                            Log.e(getClass().getName(), "Error copying buffered conent.", e);               
                        }
                    }
                } else if ( mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000 ){ 
                    //  NOTE:  The media player has stopped at the end so transfer any existing buffered data
                    //  We test for < 1second of data because the media player can stop when there is still
                    //  a few milliseconds of data left to play
                    transferBufferToMediaPlayer();
                }
            }
        };
        handler.post(updater);
    }

    private void startMediaPlayer() {
        try {   
            File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");

            // We double buffer the data to avoid potential read/write errors that could happen if the 
            // download thread attempted to write at the same time the MediaPlayer was trying to read.
            // For example, we can't guarantee that the MediaPlayer won't open a file for playing and leave it locked while 
            // the media is playing.  This would permanently deadlock the file download.  To avoid such a deadloack, 
            // we move the currently loaded data to a temporary buffer file that we start playing while the remaining 
            // data downloads.  
            moveFile(downloadingMediaFile,bufferedFile);

            Log.e(getClass().getName(),"Buffered File path: " + bufferedFile.getAbsolutePath());
            Log.e(getClass().getName(),"Buffered File length: " + bufferedFile.length()+"");

            mediaPlayer = createMediaPlayer(bufferedFile);

            // We have pre-loaded enough content and started the MediaPlayer so update the buttons & progress meters.
            mediaPlayer.start();
            startPlayProgressUpdater();         
            playButton.setEnabled(true);
        } catch (IOException e) {
            Log.e(getClass().getName(), "Error initializing the MediaPlayer.", e);
            return;
        }   
    }

    private MediaPlayer createMediaPlayer(File mediaFile)
    throws IOException {
        MediaPlayer mPlayer = new MediaPlayer();
        mPlayer.setOnErrorListener(
                new MediaPlayer.OnErrorListener() {
                    public boolean onError(MediaPlayer mp, int what, int extra) {
                        Log.e(getClass().getName(), "Error in MediaPlayer: (" + what +") with extra (" +extra +")" );
                        return false;
                    }
                });

        //  It appears that for security/permission reasons, it is better to pass a FileDescriptor rather than a direct path to the File.
        //  Also I have seen errors such as "PVMFErrNotSupported" and "Prepare failed.: status=0x1" if a file path String is passed to
        //  setDataSource().  So unless otherwise noted, we use a FileDescriptor here.
        @SuppressWarnings("resource")
        FileInputStream fis = new FileInputStream(mediaFile);
        mPlayer.setDataSource(fis.getFD());
        mPlayer.prepare();
        return mPlayer;
    }

    /**
     * Transfer buffered data to the MediaPlayer.
     * NOTE: Interacting with a MediaPlayer on a non-main UI thread can cause thread-lock and crashes so 
     * this method should always be called using a Handler.
     */  
    private void transferBufferToMediaPlayer() {
        try {
            // First determine if we need to restart the player after transferring data...e.g. perhaps the user pressed pause
            boolean wasPlaying = mediaPlayer.isPlaying();
            int curPosition = mediaPlayer.getCurrentPosition();

            // Copy the currently downloaded content to a new buffered File.  Store the old File for deleting later. 
            File oldBufferedFile = new File(context.getCacheDir(),"playingMedia" + counter + ".dat");
            File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");

            //  This may be the last buffered File so ask that it be delete on exit.  If it's already deleted, then this won't mean anything.  If you want to 
            // keep and track fully downloaded files for later use, write caching code and please send me a copy.
            bufferedFile.deleteOnExit();   
            moveFile(downloadingMediaFile,bufferedFile);

            // Pause the current player now as we are about to create and start a new one.  So far (Android v1.5),
            // this always happens so quickly that the user never realized we've stopped the player and started a new one
            mediaPlayer.pause();

            // Create a new MediaPlayer rather than try to re-prepare the prior one.
            mediaPlayer = createMediaPlayer(bufferedFile);
            mediaPlayer.seekTo(curPosition);

            //  Restart if at end of prior buffered content or mediaPlayer was previously playing.  
            //  NOTE:  We test for < 1second of data because the media player can stop when there is still
            //  a few milliseconds of data left to play
            boolean atEndOfFile = mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000;
            if (wasPlaying || atEndOfFile){
                mediaPlayer.start();
            }

            // Lastly delete the previously playing buffered File as it's no longer needed.
            oldBufferedFile.delete();

        }catch (Exception e) {
            Log.e(getClass().getName(), "Error updating to newly loaded content.", e);                  
        }
    }

    private void fireDataLoadUpdate() {
        Runnable updater = new Runnable() {
            public void run() {
                textStreamed.setText((totalKbRead + " Kb read"));
                float loadProgress = ((float)totalKbRead/(float)mediaLengthInKb);
                progressBar.setSecondaryProgress((int)(loadProgress*100));
            }
        };
        handler.post(updater);
    }

    private void fireDataFullyLoaded() {
        Runnable updater = new Runnable() { 
            public void run() {
                transferBufferToMediaPlayer();

                // Delete the downloaded File as it's now been transferred to the currently playing buffer file.
                downloadingMediaFile.delete();
                textStreamed.setText(("Audio full loaded: " + totalKbRead + " Kb read"));
            }
        };
        handler.post(updater);
    }

    public MediaPlayer getMediaPlayer() {
        return mediaPlayer;
    }

    public void startPlayProgressUpdater() {
        float progress = (((float)mediaPlayer.getCurrentPosition()/1000)/mediaLengthInSeconds);
        progressBar.setProgress((int)(progress*100));

        if (mediaPlayer.isPlaying()) {
            Runnable notification = new Runnable() {
                public void run() {
                    startPlayProgressUpdater();
                }
            };
            handler.postDelayed(notification,1000);
        }
    }    

    public void interrupt() {
        playButton.setEnabled(false);
        isInterrupted = true;
        validateNotInterrupted();
    }

    /**
     *  Move the file in oldLocation to newLocation.
     */
    public void moveFile(File oldLocation, File newLocation)
    throws IOException {

        if ( oldLocation.exists( )) {
            BufferedInputStream  reader = new BufferedInputStream( new FileInputStream(oldLocation) );
            BufferedOutputStream  writer = new BufferedOutputStream( new FileOutputStream(newLocation, false));
            try {
                byte[]  buff = new byte[8192];
                int numChars;
                while ( (numChars = reader.read(  buff, 0, buff.length ) ) != -1) {
                    writer.write( buff, 0, numChars );
                }
            } catch( IOException ex ) {
                throw new IOException("IOException when transferring " + oldLocation.getPath() + " to " + newLocation.getPath());
            } finally {
                try {
                    if ( reader != null ){                      
                        writer.close();
                        reader.close();
                    }
                } catch( IOException ex ){
                    Log.e(getClass().getName(),"Error closing files when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() ); 
                }
            }
        } else {
            throw new IOException("Old location does not exist when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
        }
    }
}

我需要一个可以播放此网址的播放器:

Streaming: http://69.64.48.96:9880

一个简单的应用程序,只有一个按钮播放和停止。我使用 MediaPlayer 做了另一个应用程序,但仅适用于 2.x 和 3.x 版本,4.x 不起作用 然后我会尝试使用此类但不知道如何将其称为播放按钮。

我试过了:

public void onClick () {
    try {
        startStreaming ("http://69.64.48.96:9880", 50, 10);
    } Catch (IOException e) {
        e.printStackTrace ();
    }
}

但它不应该是这样,因为当我调用播放按钮时会关闭应用程序。

这是我的初始应用程序,但不适用于 android 4.x。

import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Toast;
import java.io.IOException;

public class Main extends Activity  implements OnPreparedListener{
    public String url = "http://69.64.48.96:9880/";
    public MediaPlayer player = new MediaPlayer();

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        play();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void stop(){
        Toast.makeText(getApplicationContext(), "Finalizando...", Toast.LENGTH_SHORT).show();
        if(player.isPlaying()){
            player.stop();
            player.reset();
        }
    }

    public void play(){

        if(player.isPlaying()){
            Toast.makeText(getApplicationContext(), "Já está em execução!", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(getApplicationContext(), "Preparando...", Toast.LENGTH_SHORT).show();
            player.setAudioStreamType(AudioManager.STREAM_MUSIC);
            player.setAudioStreamType(AudioManager.STREAM_NOTIFICATION);
            try {
                player.setDataSource(url);
            } catch (IllegalArgumentException e) {
                e.printStackTrace();
            } catch (SecurityException e) {
                e.printStackTrace();
            } catch (IllegalStateException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                player.setOnPreparedListener(this);
                player.prepareAsync();
            } catch (IllegalStateException e) {
                e.printStackTrace();
            }
        }
    }

    public void onPrepared(MediaPlayer mp) {
        mp.start();
    }

    public void onClick(View v){
        final int id = v.getId();
        switch (id){
        case R.id.btnPlay:
            play();
            break;
        case R.id.btnStop:
            stop();
            break;
        }
    }
}
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