Question

我正在尝试打开音频文件，但它不起作用。我不知道它是操作系统还是别的什么，但当我在Windows上时，我没有这个问题。我得到一个NullPointerException这里是错误; 我尝试使用applet，bufferedInputStream，FileStream，AudioInputStream。什么都行不通。我在Linux上。

 Exception in thread "main" java.lang.NullPointerException
    at com.sun.media.sound.SoftMidiAudioFileReader.getAudioInputStream(SoftMidiAudioFileReader.java:130)
    at javax.sound.sampled.AudioSystem.getAudioInputStream(AudioSystem.java:1111)
    at com.base.engine.core.Audio.initAudio(Audio.java:29)
    at com.base.engine.core.Audio.<init>(Audio.java:18)
    at com.base.engine.game.Game.init(Game.java:43)
    at com.base.engine.core.Starter.init(Starter.java:19)
    at com.base.engine.core.Starter.run(Starter.java:43)
    at com.base.engine.core.Starter.start(Starter.java:27)
    at com.base.engine.game.Main.main(Main.java:11)

代码

package com.base.engine.core;


    import java.io.IOException;

    import javax.sound.sampled.AudioInputStream;
    import javax.sound.sampled.AudioSystem;
    import javax.sound.sampled.Clip;
    import javax.sound.sampled.LineUnavailableException;
    import javax.sound.sampled.UnsupportedAudioFileException;

    public class Audio {

        private Clip clip;
        private int fPos = 0;

        public Audio(String filename){
            initAudio(filename);
        }

        private void initAudio(String filename){
            try {
                clip = AudioSystem.getClip();
            } catch (LineUnavailableException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
                try {
                    AudioInputStream stream = AudioSystem.getAudioInputStream(Audio.class.getResourceAsStream("res/sounds/"+filename));
                    clip.open(stream);
                } catch (UnsupportedAudioFileException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (LineUnavailableException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

        }

        public void play(){
            clip.setFramePosition(0);
            clip.start();
            fPos = clip.getFramePosition();
        }

        public void playAt(int pos){
            clip.setFramePosition(pos);
            clip.start();
            fPos = clip.getFramePosition();
        }

        public void continuePlay(){
            clip.setFramePosition(fPos);
            clip.start();
            fPos = clip.getFramePosition();
        }

        public void stop(){
            fPos = clip.getFramePosition();
            clip.stop();
        }




    }

Answer 1

试试这个。如果File存在，则只能进一步。

File f = new File("D:\\folder\\file.mp3");
System.out.print(f.exists());

打开音频时出现NullPointerException

1 个答案: