我试图制作可运行的JAR,但由于某种原因,我无法玩游戏。我做了一些研究,并通过命令提示符运行它来尝试查找错误,并在下面得到了此信息。所以很明显,我知道我只需要解决此问题。我是编程新手,所以不太确定这会告诉我什么。
Exception in thread "main" java.lang.NullPointerException
at java.base/java.util.Objects.requireNonNull(Unknown Source)
at java.desktop/javax.sound.sampled.AudioSystem.getAudioInputStream(Unknown Source)
at builder.AudioPlayer.playMenuSound(AudioPlayer.java:20)
at builder.Game.<init>(Game.java:56)
at builder.Game.main(Game.java:61)
package builder;
import java.io.File;
import java.io.IOException;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.FloatControl;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;
public class AudioPlayer {
private static Clip play;
public static void playMenuSound()
{
try {
//AudioInputStream menuSound = AudioSystem.getAudioInputStream(new File("src/res/introSong.wav")); //Take in audio from res folder
AudioInputStream menuSound = AudioSystem.getAudioInputStream(AudioPlayer.class.getClassLoader().getResourceAsStream("res/introSong.wav"));
play = AudioSystem.getClip(); //
play.open(menuSound); //Play the sound
FloatControl volume = (FloatControl) play.getControl(FloatControl.Type.MASTER_GAIN); //Get control of volume
volume.setValue(1.0f); //0.0 - 1.0 volume
play.loop(Clip.LOOP_CONTINUOUSLY); //Loop once clip is over
}catch (LineUnavailableException | IOException | UnsupportedAudioFileException e){
e.printStackTrace();
}
}
public static void playGameSound()
{
try {
//AudioInputStream gameSound = AudioSystem.getAudioInputStream(new File("src/res/inGame.wav")); //Take in audio from res folder
AudioInputStream gameSound = AudioSystem.getAudioInputStream(AudioPlayer.class.getClassLoader().getResourceAsStream("res/inGame.wav"));
play = AudioSystem.getClip(); //
play.open(gameSound); //Play the sound
FloatControl volume = (FloatControl) play.getControl(FloatControl.Type.MASTER_GAIN); //Get control of volume
volume.setValue(0.5f); //0.0 - 1.0 volume
play.loop(Clip.LOOP_CONTINUOUSLY); //Loop once clip is over
}catch (LineUnavailableException | IOException | UnsupportedAudioFileException e){
e.printStackTrace();
}
}
public static void stopMusic()
{
play.close(); //Stop music
}
}
您的声音文件inGame.wav
位于源目录内的目录res
中。
导出时,源将被编译并复制到JAR。
这导致声音文件位于JAR的子目录res
中。
您尝试读取文件inGame.wav
,但必须改为读取res/inGame.wav
。
第二个问题是系统无法在InputStream
上设置标记。可以通过将getResourceAsStream
更改为getResource()
来解决。
AudioInputStream menuSound = AudioSystem.getAudioInputStream(AudioPlayer.class.getClassLoader().getResource("res/inGame.wav"));