电台在线背景 - Android

时间：2014-06-10 14:33:58

标签： java android sdk radio

请帮我解决这个问题。我试图让一个无线电Android应用程序在后台运行，但我失败了。你能帮我吗...这是我的代码：

Background.java 

package com.ihacks.radiolumina;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Binder;
import android.content.Intent;
import android.os.IBinder;
import android.app.Service;
import java.io.IOException;

public class Background extends Service {
private static final String TAG = null;
MediaPlayer player;
public IBinder onBind(Intent arg0) {

    return null;
}
@Override
public void onCreate() {
    super.onCreate();        
    try {
        player.setDataSource("http://www.radiolumina.ro:9000/;stream.nsv");
        } catch (IllegalArgumentException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        } 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();
        }

}
public int onStartCommand(Intent intent, int flags, int startId) {
    player.start();
    return 1;
}

public void onStart(Intent intent, int startId) {
    // TO DO
}
public IBinder onUnBind(Intent arg0) {
    // TO DO Auto-generated method
    return null;
}

public void onStop() {

}
public void onPause() {

}
@Override
public void onDestroy() {
    player.stop();
    player.release();
}

@Override
public void onLowMemory() {

}
}

Ecran.java 

package com.ihacks.radiolumina;

import java.io.IOException;

import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnBufferingUpdateListener;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.content.Context;
import android.media.AudioManager;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.content.Intent;


public class Ecran extends Activity implements OnClickListener{
private Button btnStart, btnStop;
private ProgressBar progressBar;
private MediaPlayer player;
private SeekBar volumeSeekbar = null;
private AudioManager audioManager = null; 
Intent playbackServiceIntent;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setVolumeControlStream(AudioManager.STREAM_MUSIC);
    setContentView(R.layout.activity_ecran);        
    init();     
    initMediaPlayer();
    Intent svc=new Intent(this, com.ihacks.radiolumina.Background.class);
    startService(svc);
}


private void initMediaPlayer() {
    player = new MediaPlayer();
    try {
        player.setDataSource("http://www.radiolumina.ro:9000/;stream.nsv");
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (SecurityException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    player.setOnBufferingUpdateListener(new OnBufferingUpdateListener() {

        @Override
        public void onBufferingUpdate(MediaPlayer mp, int percent) {

            Log.d("Radio_Lumina", "Ecran.initMediaPlayer().new OnBufferingUpdateListener() {...}: "+percent);

        }
    });
}

private void init() {

    progressBar = (ProgressBar) findViewById(R.id.progressBar);

    btnStart = (Button) findViewById(R.id.btnStart);
    btnStop = (Button) findViewById(R.id.btnStop);

    btnStart.setOnClickListener(this);
    btnStop.setOnClickListener(this);

    progressBar.setVisibility(View.GONE);
    volumeSeekbar = (SeekBar)findViewById(R.id.seekBar1);
    audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    volumeSeekbar.setMax(audioManager
            .getStreamMaxVolume(AudioManager.STREAM_MUSIC));
    volumeSeekbar.setProgress(audioManager
            .getStreamVolume(AudioManager.STREAM_MUSIC));   
    volumeSeekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() 
    {
        @Override
        public void onStopTrackingTouch(SeekBar arg0) 
        {
        }

        @Override
        public void onStartTrackingTouch(SeekBar arg0) 
        {
        }

        @Override
        public void onProgressChanged(SeekBar arg0, int progress, boolean arg2) 
        {
            audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,
                    progress, 0);
        }
    });}
 @Override
    protected void onPause() {
        super.onPause();
        if (player.isPlaying()) {
            player.stop();
        }
       }

@Override
public void onClick(View v) {
    int id = v.getId();
    switch(id){
    case R.id.btnStart:
        startPlaying();

        break;
    case R.id.btnStop:
        stopPlaying();

        break;
    default:
        break;
    }
}

private void startPlaying() {
    btnStop.setEnabled(true);
    btnStart.setEnabled(false);

    progressBar.setVisibility(View.VISIBLE);

    //playSeekBar.setVisibility(View.VISIBLE);

    player.prepareAsync();

    player.setOnPreparedListener(new OnPreparedListener() {

        public void onPrepared(MediaPlayer mp) {

            progressBar.setVisibility(View.GONE);
            Log.v("Radio_Lumina", "Ecran.startPlaying().new OnPreparedListener() {...}: Start of radio");
            player.start();
        }
    });
    startService(playbackServiceIntent);

}

private void stopPlaying() {
    if (player.isPlaying()) {
        player.stop();
        player.release();
        initMediaPlayer();
    }

    btnStart.setEnabled(true);
    btnStop.setEnabled(false);
    //playSeekBar.setVisibility(View.INVISIBLE);
    stopService(playbackServiceIntent);
}

}

的AndroidManifest.xml 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.ihacks.radiolumina"
android:versionCode="1"
android:versionName="2.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="19" />
<permission android:name="android.permission.INTERNET"></permission>
<uses-permission android:name="android.permission.INTERNET" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/FullscreenTheme" >
    <activity
        android:name="com.ihacks.radiolumina.Ecran"
        android:configChanges="orientation|keyboardHidden|screenSize"
        android:label="@string/app_name"
        android:theme="@style/FullscreenTheme" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <service android:name="Background"></service>
</application>

</manifest>

这是日志：

10:21:16.394: I/Process(2009): Sending signal. PID: 2009 SIG: 9
06-10 10:21:29.334: D/dalvikvm(2057): GC_FOR_ALLOC freed 61K, 5% free 2882K/3028K, paused 34ms, total 36ms
06-10 10:21:29.334: I/dalvikvm-heap(2057): Grow heap (frag case) to 4.329MB for 1507216-byte allocation
06-10 10:21:29.384: D/dalvikvm(2057): GC_FOR_ALLOC freed 2K, 4% free 4351K/4500K, paused 43ms, total 43ms
06-10 10:21:29.664: D/dalvikvm(2057): GC_FOR_ALLOC freed <1K, 4% free 4611K/4760K, paused 23ms, total 24ms
06-10 10:21:29.664: I/dalvikvm-heap(2057): Grow heap (frag case) to 5.953MB for 1440016-byte allocation
06-10 10:21:29.704: D/dalvikvm(2057): GC_FOR_ALLOC freed <1K, 3% free 6017K/6168K, paused 35ms, total 35ms
06-10 10:21:30.244: D/AndroidRuntime(2057): Shutting down VM
06-10 10:21:30.244: W/dalvikvm(2057): threadid=1: thread exiting with uncaught exception (group=0xb3aceba8)
06-10 10:21:30.254: E/AndroidRuntime(2057): FATAL EXCEPTION: main
06-10 10:21:30.254: E/AndroidRuntime(2057): Process: com.ihacks.radiolumina, PID: 2057
06-10 10:21:30.254: E/AndroidRuntime(2057): java.lang.RuntimeException: Unable to create service com.ihacks.radiolumina.Background: java.lang.NullPointerException
06-10 10:21:30.254: E/AndroidRuntime(2057):     at android.app.ActivityThread.handleCreateService(ActivityThread.java:2582)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at android.app.ActivityThread.access$1800(ActivityThread.java:135)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at android.os.Handler.dispatchMessage(Handler.java:102)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at android.os.Looper.loop(Looper.java:136)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at android.app.ActivityThread.main(ActivityThread.java:5017)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at java.lang.reflect.Method.invokeNative(Native Method)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at java.lang.reflect.Method.invoke(Method.java:515)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at dalvik.system.NativeStart.main(Native Method)
06-10 10:21:30.254: E/AndroidRuntime(2057): Caused by: java.lang.NullPointerException
06-10 10:21:30.254: E/AndroidRuntime(2057):     at com.ihacks.radiolumina.Background.onCreate(Background.java:24)
06-10 10:21:30.254: E/AndroidRuntime(2057):     at android.app.ActivityThread.handleCreateService(ActivityThread.java:2572)
06-10 10:21:30.254: E/AndroidRuntime(2057):     ... 10 more
06-10 10:26:30.654: I/Process(2057): Sending signal. PID: 2057 SIG: 9
你能帮帮我吗...我是绝望的;我也尝试用Fragments创建这个应用程序，但我可以将所有应用程序都放在一个应用程序中。

修改

此代码有效，但不适用于后台;我还删除了Background.java：

Ecran.java     包com.ihacks.radiolumina; 

import java.io.IOException;

import android.app.Activity;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnBufferingUpdateListener;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ProgressBar;
import android.content.Context;
import android.media.AudioManager;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.content.Intent;


public class Ecran extends Activity implements OnClickListener{
private Button btnStart, btnStop;
private ProgressBar progressBar;
private MediaPlayer player;
private SeekBar volumeSeekbar = null;
private AudioManager audioManager = null; 
Intent playbackServiceIntent;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setVolumeControlStream(AudioManager.STREAM_MUSIC);
    setContentView(R.layout.activity_ecran);        
    init();     
    initMediaPlayer();
}


private void initMediaPlayer() {
    player = new MediaPlayer();
    try {
        player.setDataSource("http://www.radiolumina.ro:9000/;stream.nsv");
    } catch (IllegalArgumentException e) {
        e.printStackTrace();
    } catch (SecurityException e) {
        e.printStackTrace();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    player.setOnBufferingUpdateListener(new OnBufferingUpdateListener() {

        @Override
        public void onBufferingUpdate(MediaPlayer mp, int percent) {

            Log.d("Radio_Lumina", "Ecran.initMediaPlayer().new OnBufferingUpdateListener() {...}: "+percent);

        }
    });
}

private void init() {

    progressBar = (ProgressBar) findViewById(R.id.progressBar);

    btnStart = (Button) findViewById(R.id.btnStart);
    btnStop = (Button) findViewById(R.id.btnStop);

    btnStart.setOnClickListener(this);
    btnStop.setOnClickListener(this);

    progressBar.setVisibility(View.GONE);
    volumeSeekbar = (SeekBar)findViewById(R.id.seekBar1);
    audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    volumeSeekbar.setMax(audioManager
            .getStreamMaxVolume(AudioManager.STREAM_MUSIC));
    volumeSeekbar.setProgress(audioManager
            .getStreamVolume(AudioManager.STREAM_MUSIC));   
    volumeSeekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() 
    {
        @Override
        public void onStopTrackingTouch(SeekBar arg0) 
        {
        }

        @Override
        public void onStartTrackingTouch(SeekBar arg0) 
        {
        }

        @Override
        public void onProgressChanged(SeekBar arg0, int progress, boolean arg2) 
        {
            audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,
                    progress, 0);
        }
    });}
 @Override
    protected void onPause() {
        super.onPause();
        if (player.isPlaying()) {
            player.stop();
        }
       }

@Override
public void onClick(View v) {
    int id = v.getId();
    switch(id){
    case R.id.btnStart:
        startPlaying();

        break;
    case R.id.btnStop:
        stopPlaying();

        break;
    default:
        break;
    }
}

private void startPlaying() {
    btnStop.setEnabled(true);
    btnStart.setEnabled(false);

    progressBar.setVisibility(View.VISIBLE);

    //playSeekBar.setVisibility(View.VISIBLE);

    player.prepareAsync();

    player.setOnPreparedListener(new OnPreparedListener() {

        public void onPrepared(MediaPlayer mp) {

            progressBar.setVisibility(View.GONE);
            Log.v("Radio_Lumina", "Ecran.startPlaying().new OnPreparedListener() {...}: Start of radio");
            player.start();
        }
    });


}

private void stopPlaying() {
    if (player.isPlaying()) {
        player.stop();
        player.release();
        initMediaPlayer();
    }

    btnStart.setEnabled(true);
    btnStop.setEnabled(false);
    //playSeekBar.setVisibility(View.INVISIBLE);

}

}

干杯， 阿德里安

1 个答案:

答案 0 :(得分：1)

  

背景：java.lang.NullPointerException

代码中的某处有一个NullPointerException。它将在您的日志中，通读它。

如果还建议阅读this article on how to debug small programs。

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