Question

我正在使用Cloud9 IDE编写Java程序。我想用MP3音频文件实现某种工作。我下载并设置了MP3SPI。我编写了简单的测试程序，它使用了这个API。

import javax.sound.sampled.*;
import java.io.*;

public class testmp {


 public static void main(String[] args) {
  testPlay("../../tmp_mp3/Redfoo.mp3");
 }

 public static void testPlay(String filename) {
  try {
   File file = new File(filename);
   AudioInputStream in = AudioSystem.getAudioInputStream(file);
   AudioInputStream din = null;
   AudioFormat baseFormat = in .getFormat();
   AudioFormat decodedFormat = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
    baseFormat.getSampleRate(),
    16,
    baseFormat.getChannels(),
    baseFormat.getChannels() * 2,
    baseFormat.getSampleRate(),
    false);
   din = AudioSystem.getAudioInputStream(decodedFormat, in ); in .close();
  } catch (Exception e) {
   //Handle exception.
  }
 }

}

当我使用java testmp运行时，我会收到

java.awt.HeadlessException: 
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
        at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207)

我尝试打开无头模式：java -Djava.awt.headless=true testmp。接收：

java.awt.HeadlessException
        at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207)

此应用程序不需要使用显示器和/或键盘，所以我不明白，为什么它使用X11。我找到了this问题的解决方案，但是下载的文件存档了。

如何让它在终端中运行？我不需要播放MP3，我想修改音频数据（帧）并将其写入其他MP3文件。

完整错误堆栈跟踪：

java.awt.HeadlessException
        at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:207)
        at java.awt.Window.<init>(Window.java:535)
        at java.awt.Frame.<init>(Frame.java:420)
        at java.awt.Frame.<init>(Frame.java:385)
        at com.trend.iwss.jscan.runtime.BaseDialog.getActiveFrame(BaseDialog.java:75)
        at com.trend.iwss.jscan.runtime.AllowDialog.make(AllowDialog.java:32)
        at com.trend.iwss.jscan.runtime.PolicyRuntime.showAllowDialog(PolicyRuntime.java:325)
        at com.trend.iwss.jscan.runtime.PolicyRuntime.stopActionInner(PolicyRuntime.java:240)
        at com.trend.iwss.jscan.runtime.PolicyRuntime.stopAction(PolicyRuntime.java:172)
        at com.trend.iwss.jscan.runtime.FileIOPolicyRuntime.doStopAction(FileIOPolicyRuntime.java:281)
        at com.trend.iwss.jscan.runtime.FileIOPolicyRuntime._preFilter(FileIOPolicyRuntime.java:260)
        at com.trend.iwss.jscan.runtime.PolicyRuntime.preFilter(PolicyRuntime.java:132)
        at com.trend.iwss.jscan.runtime.FileIOPolicyRuntime.preFilter(FileIOPolicyRuntime.java:171)
        at com.sun.media.codec.audio.mp3.JS_MP3FileReader.getAudioInputStream(JS_MP3FileReader.java:113)
        at javax.sound.sampled.AudioSystem.getAudioInputStream(AudioSystem.java:1179)
        at testmp.testPlay(testmp.java:16)
        at testmp.main(testmp.java:9)

MP3SPI中的java.awt.HeadlessException

0 个答案: