我使用下面的方法播放錄製的聲音,它工作正常,但它爲什麼只播放一次,第二次單擊播放按鈕時,它什麼都不做,如何重置數據?Java聲音只播放一次?
// Write data to the OutputChannel.
public class Playback implements Runnable
{
SourceDataLine line;
Thread thread;
public void start()
{
errStr=null;
thread=new Thread(this);
thread.setName("Playback");
thread.start();
}
public void stop() { thread=null; }
private void shutDown(String message)
{
if ((errStr=message)!=null)
{
System.err.println(errStr);
samplingGraph.repaint();
}
if (thread!=null)
{
thread=null;
samplingGraph.stop();
if (Java_Sound.Running_In_All_Permissions_Mode) captB.setEnabled(true);
pausB.setEnabled(false);
playB.setText("Play");
}
}
public void run()
{
AudioFormat format=formatControls.getFormat(); // get an AudioInputStream of the desired format for playback
AudioInputStream playbackInputStream=AudioSystem.getAudioInputStream(format,audioInputStream);
if (playbackInputStream==null)
{
shutDown("Unable to convert stream of format "+audioInputStream+" to format "+format);
return;
}
SourceDataLine.Info info=new DataLine.Info(SourceDataLine.class,format); // define the required attributes for our line,and make sure a compatible line is supported.
if (AudioSystem.isLineSupported(info))
{
try // get and open the source data line for playback.
{
line=(SourceDataLine)AudioSystem.getLine(info);
line.open(format,bufSize);
}
catch (LineUnavailableException ex)
{
shutDown("Unable to open the line: "+ex);
return;
}
int frameSizeInBytes=format.getFrameSize(); // play back the captured audio data
int bufferLengthInFrames=line.getBufferSize()/8;
int bufferLengthInBytes=bufferLengthInFrames*frameSizeInBytes;
byte[] data=new byte[bufferLengthInBytes];
int numBytesRead=0;
line.start(); // start the source data line
while (thread!=null)
{
try
{
if ((numBytesRead=playbackInputStream.read(data))==-1) break;
int numBytesRemaining=numBytesRead;
while (numBytesRemaining>0) { numBytesRemaining-=line.write(data,0,numBytesRemaining); }
}
catch (Exception e)
{
shutDown("Error during playback: "+e);
break;
}
}
}
if (thread!=null) line.drain(); // we reached the end of the stream. Let the data play out,then stop and close the line.
line.stop();
line.close();
line=null;
shutDown(null);
}
}
經過我的測試,我發現這條線是造成問題
「if ((numBytesRead=playbackInputStream.read(data))==-1) break;
」
我第一次回放,有數據,它工作得很好,但第二次,它打破了。爲什麼?如何解決它?