我正在尝试通过JMF库为学校项目创建一个简单的mp3播放器,但我总是有这个错误。该文件的路径是正确的。
java.lang.NullPointerException
at javax.media.MediaLocator.<init>(MediaLocator.java:37)
at Mp3Player.run(Mp3Player.java:40)
这是我的代码:
import java.net.URL;
import javax.media.ControllerEvent;
import javax.media.ControllerListener;
import javax.media.EndOfMediaEvent;
import javax.media.Manager;
import javax.media.MediaLocator;
import javax.media.Player;
public class Mp3Player extends Thread {
private String filename;
Player player;
public Mp3Player(String mp3Filename) {
this.filename = mp3Filename;
}
public void run() {
try {
URL url = this.getClass().getClassLoader().getResource(filename);
MediaLocator locator = new MediaLocator(url);
player = Manager.createPlayer(locator);
player.addControllerListener(new ControllerListener() {
public void controllerUpdate(ControllerEvent event) {
if (event instanceof EndOfMediaEvent) {
player.stop();
player.close();
}
}
});
player.realize();
player.start();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new Mp3Player("C:\\Users\\Aziz\\Music\\music\\a.mp3").start();
}
}
答案 0 :(得分:0)
这个字符串URL url = this.getClass().getClassLoader().getResource(filename);
似乎很可疑。
尝试使用File
中具有方法java.io.*
:
toURL()
File f = new File ( filename );
MediaLocator locator = new MediaLocator ( f.toURL() );
player = Manager.createPlayer ( locator );