Android: 使用网页在媒体播放器中显示当前曲目信息
Android: Display current track Info in mediaplayer using webpage
我是一名学习者，正在开发一个 Android 应用程序来播放直播。除 1 个问题外，它工作正常。我想显示 webpge 上可用的当前播放曲目的标题。为此，我使用了 textView 并尝试使用 Asynchronous Task 并在该异步任务中调用了一个包含 Runnable 的方法，我可以使用该方法以 30 seconds.In runnable 的时间间隔更新 textView 的文本我调用了一个加载的方法一个网页并将其内容作为字符串提供。
问题：当它尝试更新 textView 的文本时，应用程序崩溃。提前致谢。
以下是我的代码：
import java.io.IOException;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Handler;
import java.net.URLConnection;
import java.net.URL;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import android.util.Log;
import java.net.MalformedURLException;
import android.widget.TextView;
import android.os.AsyncTask;
public class MusicAndroidActivity extends Activity {
static MediaPlayer mPlayer;
Button buttonPlay;
Button buttonStop;
Button buttonPause;
public TextView txtMessage;
private StringBuilder response;
private String text="***";
ProgressDialog progDailog;
private final static int INTERVAL = 1000 * 30; //2 minutes
Handler mHandler;
int length=0;
String url = "http://www.s8.voscast.com:9630/;stream.mp3";
private final Handler handler = new Handler();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
buttonStop = (Button) findViewById(R.id.stop);
txtMessage=(TextView)findViewById(R.id.txtMessage);
buttonStop.setEnabled(false);
buttonPause=(Button) findViewById(R.id.pause);
buttonPause.setEnabled(false);
buttonPlay = (Button) findViewById(R.id.play);
buttonPlay.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPlayer = new MediaPlayer();
mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
buttonPlay.setEnabled(false);
buttonStop.setEnabled(true);
buttonPause.setEnabled(true);
//txtMessage.setText("Loading...");
progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true);
mPlayer.setDataSource(url);
} catch (IllegalArgumentException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (SecurityException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
}
try {
mPlayer.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mPlayer) {
// TODO Auto-generated method stub
mPlayer.start();
progDailog.dismiss();
LoadWebPageASYNC task = new LoadWebPageASYNC();
task.execute(new String[]{"http://khilare.com/swltest/sms.html"});
}
});
mPlayer.prepareAsync();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} //catch (IOException e) {
//Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
//}
}
});
buttonStop.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.stop();
buttonPlay.setEnabled(true);
buttonStop.setEnabled(false);
buttonPause.setEnabled(false);
}
}
});
buttonPause.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.pause();
length=mPlayer.getCurrentPosition();
buttonPause.setText("Resume");
//buttonPlay.setEnabled(true);
buttonStop.setEnabled(true);
buttonPlay.setEnabled(false);
//sapp();
//getHTML();
//txtMessage.setText(text);
txtMessage.setText(text);
}
else {
//mPlayer.seekTo(length);
mPlayer.start();
// mPlayer.seekTo(length);
buttonPause.setText("Pause");
}
}
});
}
protected void onDestroy() {
super.onDestroy();
// TODO Auto-generated method stub
if (mPlayer != null) {
mPlayer.release();
mPlayer = null;
}
}
private class LoadWebPageASYNC extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
getHTML();
//sapp();
txtMessage.setText(text);
return null;
}
}
private void sapp()
{
//Runnable updater1 = new Runnable() {
handler.postDelayed(new Runnable() {
//@Override
public void run() {
getHTML();
txtMessage.setText(text);
}
}, INTERVAL);
/*public void run() {
getHTML();
txtMessage.setText(text);
}
};*/
//handler.post(updater1);
}
private void getHTML()
{
try {
URLConnection connection = new URL("http://khilare.com/swltest/sms.html").openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
line = br.readLine();
{
response.append(line);
}
text = response.toString();
//txtMessage.setText(text);
//Log.i("Output", text);
} catch (MalformedURLException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
} catch (IOException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
}
//textStreamed.setText(text);
}
}
这里是Logcat:
java.lang.SecurityException: Permission denial: writing to settings requires android.permission.WRITE_SETTINGS
at com.android.providers.settings.SettingsProvider.callFromPackage(SettingsProvider.java:645)
at android.content.ContentProvider$Transport.call(ContentProvider.java:279)
at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:273)
at android.os.Binder.execTransact(Binder.java:388)
at dalvik.system.NativeStart.run(Native Method)
05-29 10:56:45.772 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:45.772 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:48.462 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:48.462 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.702 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.702 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.712 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.712 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:57:01.772 28164-28569/com.prgguru.example E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
at java.util.concurrent.FutureTask.run(FutureTask.java:239)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:5969)
at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:921)
at android.view.ViewGroup.invalidateChild(ViewGroup.java:4276)
at android.view.View.invalidate(View.java:10552)
at android.view.View.invalidate(View.java:10507)
at android.widget.TextView.checkForRelayout(TextView.java:6531)
at android.widget.TextView.setText(TextView.java:3789)
at android.widget.TextView.setText(TextView.java:3643)
at android.widget.TextView.setText(TextView.java:3618)
at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:158)
at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:152)
at android.os.AsyncTask.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
我明白了。
我使用了 TimeTask，它每 10 秒调用一个方法 UpdateGUI();。此方法“UpdateGUI();”进一步调用方法“getHTML();”，将网页内容加载到字符串文本。此方法还通过 myHandler 在
调用 myRunnable
myHandler.post(myRunnable);
和myRunnable设置textView的文本txtMessage
要完整了解流程，请阅读this Article
现在的代码是：
import java.io.IOException;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Handler;
import java.net.URLConnection;
import java.net.URL;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import android.util.Log;
import java.net.MalformedURLException;
import android.widget.TextView;
import java.util.TimerTask;
import java.util.Timer;
public class MusicAndroidActivity extends Activity {
static MediaPlayer mPlayer;
Button buttonPlay;
Button buttonStop;
Button buttonPause;
public TextView txtMessage;
private StringBuilder response;
private String text="***";
ProgressDialog progDailog;
final Handler myHandler = new Handler();
int length=0;
String url = "http://www.example.com:port/;stream.mp3";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
buttonStop = (Button) findViewById(R.id.stop);
txtMessage=(TextView)findViewById(R.id.txtMessage);
buttonStop.setEnabled(false);
buttonPause=(Button) findViewById(R.id.pause);
buttonPause.setEnabled(false);
buttonPlay = (Button) findViewById(R.id.play);
buttonPlay.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPlayer = new MediaPlayer();
mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
buttonPlay.setEnabled(false);
buttonStop.setEnabled(true);
buttonPause.setEnabled(true);
progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true);
mPlayer.setDataSource(url);
} catch (IllegalArgumentException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (SecurityException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
}
try {
mPlayer.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mPlayer) {
// TODO Auto-generated method stub
mPlayer.start();
progDailog.dismiss();
}
});
mPlayer.prepareAsync();
Timer myTimer = new Timer(); // Declared Timer
myTimer.schedule(new TimerTask() { // Started Time Task, it will repeat as per given duration (Ours is 1000 or 10 Second)
@Override
public void run() {
UpdateGUI(); // Called Method UdateGUI
} // v
}, 0, 10000); // After Every 10 Seconds
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
}
}
});
buttonStop.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.stop();
buttonPlay.setEnabled(true);
buttonStop.setEnabled(false);
buttonPause.setEnabled(false);
}
}
});
buttonPause.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.pause();
length=mPlayer.getCurrentPosition();
buttonPause.setText("Play");
buttonStop.setEnabled(true);
buttonPlay.setEnabled(false);
}
else {
mPlayer.start();
buttonPause.setText("Pause");
}
}
});
}
protected void onDestroy() {
super.onDestroy();
// TODO Auto-generated method stub
if (mPlayer != null) {
mPlayer.release();
mPlayer = null;
}
}
private void UpdateGUI() {
getHTML();
myHandler.post(myRunnable); // Posted MyRunnable to myHandler
}
final Runnable myRunnable = new Runnable() {
public void run() {
txtMessage.setText(text); //Set txtMessage's value to text (text is a string declared above)
}
};
private void getHTML()
{
try {
URLConnection connection = new URL("http://example.com/stats/index.php").openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
line = br.readLine();
{
response.append(line);
}
text = response.toString();
} catch (MalformedURLException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
} catch (IOException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
}
}
}
我是一名学习者，正在开发一个 Android 应用程序来播放直播。除 1 个问题外，它工作正常。我想显示 webpge 上可用的当前播放曲目的标题。为此，我使用了 textView 并尝试使用 Asynchronous Task 并在该异步任务中调用了一个包含 Runnable 的方法，我可以使用该方法以 30 seconds.In runnable 的时间间隔更新 textView 的文本我调用了一个加载的方法一个网页并将其内容作为字符串提供。
问题：当它尝试更新 textView 的文本时，应用程序崩溃。提前致谢。
以下是我的代码：
import java.io.IOException;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Handler;
import java.net.URLConnection;
import java.net.URL;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import android.util.Log;
import java.net.MalformedURLException;
import android.widget.TextView;
import android.os.AsyncTask;
public class MusicAndroidActivity extends Activity {
static MediaPlayer mPlayer;
Button buttonPlay;
Button buttonStop;
Button buttonPause;
public TextView txtMessage;
private StringBuilder response;
private String text="***";
ProgressDialog progDailog;
private final static int INTERVAL = 1000 * 30; //2 minutes
Handler mHandler;
int length=0;
String url = "http://www.s8.voscast.com:9630/;stream.mp3";
private final Handler handler = new Handler();
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
buttonStop = (Button) findViewById(R.id.stop);
txtMessage=(TextView)findViewById(R.id.txtMessage);
buttonStop.setEnabled(false);
buttonPause=(Button) findViewById(R.id.pause);
buttonPause.setEnabled(false);
buttonPlay = (Button) findViewById(R.id.play);
buttonPlay.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPlayer = new MediaPlayer();
mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
buttonPlay.setEnabled(false);
buttonStop.setEnabled(true);
buttonPause.setEnabled(true);
//txtMessage.setText("Loading...");
progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true);
mPlayer.setDataSource(url);
} catch (IllegalArgumentException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (SecurityException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
}
try {
mPlayer.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mPlayer) {
// TODO Auto-generated method stub
mPlayer.start();
progDailog.dismiss();
LoadWebPageASYNC task = new LoadWebPageASYNC();
task.execute(new String[]{"http://khilare.com/swltest/sms.html"});
}
});
mPlayer.prepareAsync();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} //catch (IOException e) {
//Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
//}
}
});
buttonStop.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.stop();
buttonPlay.setEnabled(true);
buttonStop.setEnabled(false);
buttonPause.setEnabled(false);
}
}
});
buttonPause.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.pause();
length=mPlayer.getCurrentPosition();
buttonPause.setText("Resume");
//buttonPlay.setEnabled(true);
buttonStop.setEnabled(true);
buttonPlay.setEnabled(false);
//sapp();
//getHTML();
//txtMessage.setText(text);
txtMessage.setText(text);
}
else {
//mPlayer.seekTo(length);
mPlayer.start();
// mPlayer.seekTo(length);
buttonPause.setText("Pause");
}
}
});
}
protected void onDestroy() {
super.onDestroy();
// TODO Auto-generated method stub
if (mPlayer != null) {
mPlayer.release();
mPlayer = null;
}
}
private class LoadWebPageASYNC extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
getHTML();
//sapp();
txtMessage.setText(text);
return null;
}
}
private void sapp()
{
//Runnable updater1 = new Runnable() {
handler.postDelayed(new Runnable() {
//@Override
public void run() {
getHTML();
txtMessage.setText(text);
}
}, INTERVAL);
/*public void run() {
getHTML();
txtMessage.setText(text);
}
};*/
//handler.post(updater1);
}
private void getHTML()
{
try {
URLConnection connection = new URL("http://khilare.com/swltest/sms.html").openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
line = br.readLine();
{
response.append(line);
}
text = response.toString();
//txtMessage.setText(text);
//Log.i("Output", text);
} catch (MalformedURLException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
} catch (IOException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
}
//textStreamed.setText(text);
}
}
这里是Logcat:
java.lang.SecurityException: Permission denial: writing to settings requires android.permission.WRITE_SETTINGS
at com.android.providers.settings.SettingsProvider.callFromPackage(SettingsProvider.java:645)
at android.content.ContentProvider$Transport.call(ContentProvider.java:279)
at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:273)
at android.os.Binder.execTransact(Binder.java:388)
at dalvik.system.NativeStart.run(Native Method)
05-29 10:56:45.772 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:45.772 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:48.462 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:48.462 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.702 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.702 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.712 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:56:50.712 302-302/? E/Parcel﹕ Reading a NULL string not supported here.
05-29 10:57:01.772 28164-28569/com.prgguru.example E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
at java.util.concurrent.FutureTask.run(FutureTask.java:239)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:5969)
at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:921)
at android.view.ViewGroup.invalidateChild(ViewGroup.java:4276)
at android.view.View.invalidate(View.java:10552)
at android.view.View.invalidate(View.java:10507)
at android.widget.TextView.checkForRelayout(TextView.java:6531)
at android.widget.TextView.setText(TextView.java:3789)
at android.widget.TextView.setText(TextView.java:3643)
at android.widget.TextView.setText(TextView.java:3618)
at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:158)
at com.prgguru.example.MusicAndroidActivity$LoadWebPageASYNC.doInBackground(MusicAndroidActivity.java:152)
at android.os.AsyncTask.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask.run(FutureTask.java:234)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
at java.lang.Thread.run(Thread.java:841)
我明白了。
我使用了 TimeTask，它每 10 秒调用一个方法 UpdateGUI();。此方法“UpdateGUI();”进一步调用方法“getHTML();”，将网页内容加载到字符串文本。此方法还通过 myHandler 在
调用 myRunnablemyHandler.post(myRunnable);
和myRunnable设置textView的文本txtMessage
要完整了解流程，请阅读this Article
现在的代码是：
import java.io.IOException;
import android.app.Activity;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.app.ProgressDialog;
import android.media.MediaPlayer.OnPreparedListener;
import android.os.Handler;
import java.net.URLConnection;
import java.net.URL;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import android.util.Log;
import java.net.MalformedURLException;
import android.widget.TextView;
import java.util.TimerTask;
import java.util.Timer;
public class MusicAndroidActivity extends Activity {
static MediaPlayer mPlayer;
Button buttonPlay;
Button buttonStop;
Button buttonPause;
public TextView txtMessage;
private StringBuilder response;
private String text="***";
ProgressDialog progDailog;
final Handler myHandler = new Handler();
int length=0;
String url = "http://www.example.com:port/;stream.mp3";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
buttonStop = (Button) findViewById(R.id.stop);
txtMessage=(TextView)findViewById(R.id.txtMessage);
buttonStop.setEnabled(false);
buttonPause=(Button) findViewById(R.id.pause);
buttonPause.setEnabled(false);
buttonPlay = (Button) findViewById(R.id.play);
buttonPlay.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPlayer = new MediaPlayer();
mPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
try {
buttonPlay.setEnabled(false);
buttonStop.setEnabled(true);
buttonPause.setEnabled(true);
progDailog = ProgressDialog.show(MusicAndroidActivity.this, "", "Buffering ... \n It can take upto 1 Minute, depending upon your internet speed", true);
mPlayer.setDataSource(url);
} catch (IllegalArgumentException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (SecurityException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
}
try {
mPlayer.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mPlayer) {
// TODO Auto-generated method stub
mPlayer.start();
progDailog.dismiss();
}
});
mPlayer.prepareAsync();
Timer myTimer = new Timer(); // Declared Timer
myTimer.schedule(new TimerTask() { // Started Time Task, it will repeat as per given duration (Ours is 1000 or 10 Second)
@Override
public void run() {
UpdateGUI(); // Called Method UdateGUI
} // v
}, 0, 10000); // After Every 10 Seconds
} catch (IllegalStateException e) {
Toast.makeText(getApplicationContext(), "You might not set the URI correctly!", Toast.LENGTH_LONG).show();
}
}
});
buttonStop.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.stop();
buttonPlay.setEnabled(true);
buttonStop.setEnabled(false);
buttonPause.setEnabled(false);
}
}
});
buttonPause.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
if(mPlayer!=null && mPlayer.isPlaying()){
mPlayer.pause();
length=mPlayer.getCurrentPosition();
buttonPause.setText("Play");
buttonStop.setEnabled(true);
buttonPlay.setEnabled(false);
}
else {
mPlayer.start();
buttonPause.setText("Pause");
}
}
});
}
protected void onDestroy() {
super.onDestroy();
// TODO Auto-generated method stub
if (mPlayer != null) {
mPlayer.release();
mPlayer = null;
}
}
private void UpdateGUI() {
getHTML();
myHandler.post(myRunnable); // Posted MyRunnable to myHandler
}
final Runnable myRunnable = new Runnable() {
public void run() {
txtMessage.setText(text); //Set txtMessage's value to text (text is a string declared above)
}
};
private void getHTML()
{
try {
URLConnection connection = new URL("http://example.com/stats/index.php").openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
InputStream responseStream = connection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(responseStream));
response = new StringBuilder();
String line;
line = br.readLine();
{
response.append(line);
}
text = response.toString();
} catch (MalformedURLException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
} catch (IOException e) {
txtMessage.setText(e.getMessage());
e.printStackTrace();
}
}
}