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  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. /* Name of the class has to be "Main" only if the class is public. */
  8. class Ideone
  9. {
  10. 	private static Object obj = null;
  11. 	static void foo() {
  12. 		synchronized(obj) {
  13. 			System.out.println("Hello");
  14. 		}
  15. 	}
  16. 	public static void main (String[] args) throws java.lang.Exception
  17. 	{
  18. 		foo();
  19. 	}
  20. }
Runtime error #stdin #stdout #stderr 0.08s 380160KB
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stdin
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Standard input is empty
stdout
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Standard output is empty
stderr
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Exception in thread "main" java.lang.NullPointerException
	at Ideone.foo(Main.java:12)
	at Ideone.main(Main.java:18)
https://ideone.com/LKLQ3Z
language:
Java (HotSpot 12)
created:
10 years ago
visibility:
public

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