但是当我启动应用程序时,我有一个错误无法启动活动(ru.vspr.MyMediaPlayerActivity) java.lang.IllegalStateException
我该怎么办呢？
源代码：http://www.mediafire.com/download/y1paremphr57mbz/MyMediaPlayer.zip
日志：
07-24 13:20:01.023 E/AndroIDRuntime(22997): FATAL EXCEPTION: main07-24 13:20:01.023 E/AndroIDRuntime(22997): java.lang.RuntimeException: Unable to start activity ComponentInfo{ru.vspr/ru.vspr.MyMediaPlayerActivity}: java.lang.IllegalStateException07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.ActivityThread.performlaunchActivity(ActivityThread.java:1956)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.ActivityThread.access0(ActivityThread.java:123)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.os.Handler.dispatchMessage(Handler.java:99)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.os.Looper.loop(Looper.java:137)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.ActivityThread.main(ActivityThread.java:4424)07-24 13:20:01.023 E/AndroIDRuntime(22997): at java.lang.reflect.Method.invokeNative(Native Method)07-24 13:20:01.023 E/AndroIDRuntime(22997): at java.lang.reflect.Method.invoke(Method.java:511)07-24 13:20:01.023 E/AndroIDRuntime(22997): at com.androID.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)07-24 13:20:01.023 E/AndroIDRuntime(22997): at com.androID.internal.os.ZygoteInit.main(ZygoteInit.java:551)07-24 13:20:01.023 E/AndroIDRuntime(22997): at dalvik.system.NativeStart.main(Native Method)07-24 13:20:01.023 E/AndroIDRuntime(22997): Caused by: java.lang.IllegalStateException07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.media.MediaPlayer._reset(Native Method)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.media.MediaPlayer.reset(MediaPlayer.java:1218)07-24 13:20:01.023 E/AndroIDRuntime(22997): at ru.vspr.MyMediaPlayerActivity.loadMusic(MyMediaPlayerActivity.java:156)07-24 13:20:01.023 E/AndroIDRuntime(22997): at ru.vspr.MyMediaPlayerActivity.loadTrack(MyMediaPlayerActivity.java:147)07-24 13:20:01.023 E/AndroIDRuntime(22997): at ru.vspr.MyMediaPlayerActivity.initialize(MyMediaPlayerActivity.java:100)07-24 13:20:01.023 E/AndroIDRuntime(22997): at ru.vspr.MyMediaPlayerActivity.onCreate(MyMediaPlayerActivity.java:58)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.Activity.performCreate(Activity.java:4492)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)07-24 13:20:01.023 E/AndroIDRuntime(22997): at androID.app.ActivityThread.performlaunchActivity(ActivityThread.java:1920)07-24 13:20:01.023 E/AndroIDRuntime(22997): ... 11 more package ru.vspr;import java.io.file;import java.io.fileDescriptor;import java.io.fileinputStream;import java.io.IOException;import java.util.ArrayList;import java.util.List;import java.util.Random;import androID.app.Activity;import androID.content.Context;import androID.content.res.AssetfileDescriptor;import androID.content.res.AssetManager;import androID.graphics.drawable.Drawable;import androID.media.audiofx.Visualizer;import androID.media.AudioManager;import androID.media.MediaPlayer;import androID.media.MediaPlayer.OnCompletionListener;import androID.os.Bundle;import androID.os.Environment;import androID.os.PowerManager;import androID.os.PowerManager.WakeLock;import androID.vIEw.Menu;import androID.vIEw.MenuItem;import androID.vIEw.VIEw;import androID.vIEw.Window;import androID.vIEw.WindowManager;import androID.Widget.button;import androID.Widget.ImageVIEw;import androID.Widget.Toast;import androID.util.Log;public class MyMediaPlayerActivity extends Activity implements OnCompletionListener { WakeLock wakeLock; private static final String[] EXTENSIONS = { ".mp3",".wav",".ogg" }; //Воспроизводимые форматы List<String> tracknames; //Названия воспроизводимых треков List<String> trackArtworks; //Обложки воспроизводимых треков file path; //Директория,откуда будет загружена музыка file path2; //Директория,откуда Р±СѓРґСѓС‚ загружены обложки треков button btnPlay; //Рта РєРЅРѕРїРєР° будет менять СЃРІРѕС‘ изображение РїСЂРё нажатии Random random; //Рспользовано для случайного воспроизведения boolean shuffle; //Случайное воспроизведение включено? boolean isTuning; int currentTrack; //Рндекс текущего трека MediaPlayer mediaPlayer; //Плеер Visualizer mVisualizer; //Визуализатор для него VisualizerVIEw mVisualizerVIEw; //VIEw для визуализатора @OverrIDe public voID onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); requestwindowFeature(Window.FEATURE_NO_Title); setVolumeControlStream(AudioManager.STREAM_MUSIC);// PowerManager powerManager = (PowerManager) getSystemService(Context.POWER_SERVICE);// wakeLock = powerManager.newWakeLock(PowerManager.FulL_WAKE_LOCK,"Powered by YOBA Engine"); setContentVIEw(R.layout.main); initialize(); } @OverrIDe public voID onResume(){ super.onResume(); wakeLock.acquire(); } @OverrIDe public voID onPause(){ super.onPause(); wakeLock.release(); if(mediaPlayer != null){ if(isPlaying()){ pause(); isTuning = false; btnPlay.setBackgroundResource(R.drawable.play); } if(isFinishing()){ dispose(); finish(); } } else{ if(isFinishing()){ finish(); } } } private voID initialize(){ btnPlay = (button) findVIEwByID(R.ID.btnPlay); btnPlay.setBackgroundResource(R.drawable.play); tracknames = new ArrayList<String>(); trackArtworks = new ArrayList<String>(); currentTrack = 0; shuffle = false; isTuning = false; random = new Random(); mediaPlayer = new MediaPlayer(); addTracks(getTracks()); loadTrack(); } //Generate a String Array that represents all of the files found private String[] getTracks(){ if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED) || Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED_READ_ONLY)){ path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC); path2 = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES); String[] temp = path.List(); return temp; } else{ Toast.makeText(getBaseContext(),"SD Card is either mounted elsewhere or is unusable",Toast.LENGTH_LONG).show(); } return null; } //Adds the playable files to the tracknames List private voID addTracks(String[] temp){ if(temp != null){ for(int i = 0; i < temp.length; i++){ //Only accept files that have one of the extensions in the EXTENSIONS array if(trackChecker(temp[i])){ tracknames.add(temp[i]); trackArtworks.add(temp[i].substring(0,temp[i].length()-4)); } } Toast.makeText(getBaseContext(),"Loaded " + Integer.toString(tracknames.size()) + " Tracks",Toast.LENGTH_SHORT).show(); } } //Checks to make sure that the track to be loaded has a correct extenson private boolean trackChecker(String trackToTest){ for(int j = 0; j < EXTENSIONS.length; j++){ if(trackToTest.contains(EXTENSIONS[j])){ return true; } } return false; } //Loads the track by calling loadMusic private voID loadTrack(){ if(mediaPlayer != null){ dispose(); } if(tracknames.size() > 0){ loadMusic(); } } //loads a Music instance using either a built in asset or an external resource private voID loadMusic(){ try{ fileinputStream fis = new fileinputStream(new file(path,tracknames.get(currentTrack))); fileDescriptor fileDescriptor = fis.getFD(); mediaPlayer.setDataSource(fileDescriptor); mediaPlayer.prepare(); mediaPlayer.setonCompletionListener(this); // setupVisualizerFxAndUI(); } catch(IOException e){ e.printstacktrace(); Toast.makeText(getBaseContext(),"Error Loading " + tracknames.get(currentTrack),Toast.LENGTH_LONG).show(); }// return null; } @OverrIDe public boolean onCreateOptionsMenu(Menu menu){ super.onCreateOptionsMenu(menu); createMenu(menu); return true; } @OverrIDe public boolean onoptionsItemSelected(MenuItem item){ switch(item.getItemID()){ case 0: //Set LooPing synchronized(this){ if(isLooPing()){ setLooPing(false); Toast.makeText(getBaseContext(),"Playing Tracks Sequentially",Toast.LENGTH_SHORT).show(); } else{ setLooPing(true); Toast.makeText(getBaseContext(),"LooPing " + tracknames.get(currentTrack),Toast.LENGTH_SHORT).show(); } } return true; case 1: //Set Shuffle synchronized(this){ if(shuffle){ setShuffle(false); } else{ setShuffle(true); } } return true; case 2: //Stop Music synchronized(this){ switchTracks(); btnPlay.setBackgroundResource(R.drawable.play); } return true; default: return false; } } private voID createMenu(Menu menu){ MenuItem miLooPing = menu.add(0,"LooPing");{ miLooPing.setIcon(R.drawable.looPing); } MenuItem miShuffle = menu.add(0,1,"Shuffle");{ miShuffle.setIcon(R.drawable.shuffle); } MenuItem miStop = menu.add(0,2,"Stop");{ miStop.setIcon(R.drawable.stop); } } public voID click(VIEw vIEw){ int ID = vIEw.getID(); switch(ID){ case R.ID.btnPlay: synchronized(this){ if(isTuning){ isTuning = false; btnPlay.setBackgroundResource(R.drawable.play); pause(); } else{ isTuning = true; btnPlay.setBackgroundResource(R.drawable.pause); playTrack(); } } return; case R.ID.btnPrevIoUs: setTrack(0); loadTrack(); playTrack(); return; case R.ID.btnNext: setTrack(1); loadTrack(); playTrack(); return; default: return; } } private voID setTrack(int direction){ if(direction == 0){ currentTrack--; if(currentTrack < 0){ currentTrack = tracknames.size()-1; } } else if(direction == 1){ currentTrack++; if(currentTrack > tracknames.size()-1){ currentTrack = 0; } } if(shuffle){ int temp = random.nextInt(tracknames.size()); while(true){ if(temp != currentTrack){ currentTrack = temp; break; } temp++; if(temp > tracknames.size()-1){ temp = 0; } } } } //Plays the Track private voID playTrack(){ if(isTuning && mediaPlayer != null){ play(); Toast.makeText(getBaseContext(),"Playing " + tracknames.get(currentTrack).substring(0,tracknames.get(currentTrack).length()-4),Toast.LENGTH_SHORT).show(); } } //Simply sets shuffle to isShuffle and then displays a message for confirmation private voID setShuffle(boolean isShuffle) { shuffle = isShuffle; if(shuffle){ Toast.makeText(getBaseContext(),"Shuffle On",Toast.LENGTH_SHORT).show(); } else{ Toast.makeText(getBaseContext(),"Shuffle Off",Toast.LENGTH_SHORT).show(); } } public voID onCompletion(MediaPlayer mediaPlayer) { synchronized(this){ } } public voID play() { if(mediaPlayer.isPlaying()){ return; } try{ synchronized(this){ mediaPlayer.start(); } } catch(IllegalStateException ex){ ex.printstacktrace(); } } public voID stop() { mediaPlayer.stop(); synchronized(this){ } } public voID switchTracks(){ mediaPlayer.seekTo(0); mediaPlayer.pause(); } public voID pause() { mediaPlayer.pause(); } public boolean isPlaying() { return mediaPlayer.isPlaying(); } public boolean isLooPing() { return mediaPlayer.isLooPing(); } public voID setLooPing(boolean isLooPing) { mediaPlayer.setLooPing(isLooPing); } public voID setVolume(float volumeleft,float volumeRight) { mediaPlayer.setVolume(volumeleft,volumeRight); } public voID dispose() { if(mediaPlayer.isPlaying()){ stop(); } mediaPlayer.release(); } public voID setupVisualizerFxAndUI() { mVisualizerVIEw = new VisualizerVIEw(this); mVisualizerVIEw = (VisualizerVIEw) findVIEwByID(R.ID.visualizerVIEw); mVisualizer = new Visualizer(mediaPlayer.getAudioSessionID()); mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]); mVisualizer.setDataCaptureListener(new Visualizer.OnDataCaptureListener() { public voID onWaveFormDataCapture(Visualizer visualizer,byte[] bytes,int samplingRate) { mVisualizerVIEw.updateVisualizer(bytes); } public voID onfftDataCapture(Visualizer visualizer,int samplingRate) {} },Visualizer.getMaxCaptureRate() / 1,true,false); }} 附：在收到此错误之前,当我按“播放”按钮时,会有声音,但不是可视化.有没有办法来解决这个问题？
P.P.S对不起我的英文
解决方法java.lang.IllegalStateException
在VM未处于正确状态时尝试执行 *** 作时抛出.
http://developer.android.com/reference/java/lang/IllegalStateException.html
07-24 12:49:27.054 E/AndroIDRuntime(21733): Caused by: java.lang.IllegalStateException 07-24 12:49:27.054 E/AndroIDRuntime(21733): at androID.media.MediaPlayer.setDataSource(Native Method) 07-24 12:49:27.054 E/AndroIDRuntime(21733): at androID.media.MediaPlayer.setDataSource(MediaPlayer.java:889)
你应该调用reset()使其恢复到空闲状态.只有这样才能调用setDataSource()
编辑：
您应该将其余代码放在onCompletion中
public voID onCompletion(MediaPlayer mediaPlayer) { try { mediaPlayer.reset(); mediaPlayer.setDataSource(path.getabsolutePath()); mediaPlayer.prepare(); mediaPlayer.setonCompletionListener(this); mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); } catch (IllegalArgumentException 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(); } } 总结 以上是内存溢出为你收集整理的(android)启动我的应用程序时出现错误java.lang.IllegalStateException全部内容，希望文章能够帮你解决(android)启动我的应用程序时出现错误java.lang.IllegalStateException所遇到的程序开发问题。
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