error: non-static variable this cannot be referenced from a static context

Question

I am having problem with this code:

package javaapplication16; import java.io.InputStream; import javax.swing.JOptionPane; import sun.audio.AudioPlayer; import sun.audio.AudioStream; public class JavaApplication16 { public static void main(String[] args) { NewJFrame n = new NewJFrame(); n.setVisible(true); InputStream is; is = this.getClass().getClassLoader().getResourceAsStream("samp.wav"); try { AudioStream audioStream; audioStream = new AudioStream(is); AudioPlayer.player.start(audioStream); } catch (Exception e) { JOptionPane.showMessageDialog(null, e); } } }

It is saying that

error: non-static variable this cannot be referenced from a static context is = this.getClass().getClassLoader().getResourceAsStream("samp.wav");

If I make the InputStream variable static then its telling me illegal start of expression. I have also removed the this keyword. Still the problem is not solving. How can fix it?

What would this be without an instance?

Dave Newton
– Dave Newton

2012-11-27 21:39:59 +00:00
Commented Nov 27, 2012 at 21:39 — Dave Newton
– Dave Newton, Commented Nov 27, 2012 at 21:39

Guido Simone · Accepted Answer · 2012-11-27 21:40:46Z

4

Just avoid the problem, like so:

JavaApplication16.class.getClassLoader().getResourceAsStream("samp.wav");

answered Nov 27, 2012 at 21:40

Guido Simone

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3 Comments

Tushar Monirul Over a year ago

owao! ! ! the error has gone. Now I can understand it. But when I run the program its giving me another exception error: java.lang.NullPointerException why?

Guido Simone Over a year ago

@Tushar I recommend you accept one of these answers to finish this question. Then submit the new problem as a new question.

Nathan Hughes Over a year ago

@Tushar: probably it can't find the wav file. getResourceAsStream returns null if the file isn't present. also: 1) I agree with Guido's comment, 2) asking people to explain an exception without showing them a stacktrace is unreasonable.

mbelow · Accepted Answer · 2012-11-27 21:42:23Z

To accomplish this, use a class literal instead:

 is = JavaApplication16.class.getClassLoader().getResourceAsStream("samp.wav");

djechlin · Accepted Answer · 2012-11-27 21:45:56Z

you cant use this keyword inside a static method. this keyword can only be used Within an instance method or a constructor. this is a reference to the current object.

try:

 is = YourClassName.class.getClassLoader().getResourceAsStream("samp.wav");

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