behaviour of finally

[aruna sydu]

I have a program.

public class FinallyTest {
	static String str;
	/**
	 * @param args
	 */
	public static void main(String[] args) {		
		System.out.println(new FinallyTest().returnData());
	}
	
	public int returnData(){
		 try   {				
		  	return 1;				
			  }catch(Exception e){
			   e.printStackTrace();
			   return 2;
			 }finally {
			 return 3;				
			}	
	  }

}
    

In the above programme the output is 3 rather than 1.
When we use a return statement the control should be returned to main but how the output is 3 ???

[Campbell Ritchie]

Because the finally block is always executed. It returns 3.

[aruna sydu]

Hi Campbell Ritchie,

Thanks for answering.

In the same program in place of

return 1 ;

in try block if we have

System.exit(0);

The system is exiting with out executing the finally block.

Should the above scenario be considered a special case?


-Aruna.

[Henry Wong]

aruna sydu wrote:
In the same program in place of

return 1 ;

in try block if we have

System.exit(0);

The system is exiting with out executing the finally block.

Should the above scenario be considered a special case?

I think that it is safe to add the phrase, "unless the JVM terminates", to almost every guarantee in java...

Henry

[aruna sydu]

Hi Henry Wong,

Thanks for the answer.


-Aruna.

[Ernest Friedman-Hill]

I can't resist pointing out that this means that using "return" in a finally block is virtually always the wrong thing to do -- don't do it!

[Campbell Ritchie]

aruna sydu wrote:
Hi Campbell Ritchie,

. . . if we have [code]System.exit(0); The system is exiting with out executing the finally block.

Should the above scenario be considered a special case?


-Aruna.

Yes, (as Henry has already said), that probably is a special case because the try block is never completed. For other reasons for a finally not being executed, searchm and you find this thread (there are others, too)

[Vishwanath Dv]

Hi aruna,


It will not return 1 ,because finally block will always excute.
If you want the value to be returned as 1, then remove the finally block.