In Java, will the code in the finally block be called and run after a return statement is executed?

 

The answer to this question is a simple yes – the code in a finally block will take precedence over the return statement. Take a look at the code below to confirm this fact:

Code that shows finally runs after return

class SomeClass
{
    public static void main(String args[]) 
    { 
        // call the proveIt method and print the return value
    	System.out.println(SomeClass.proveIt()); 
    }

    public static int proveIt()
    {
    	try {  
            	return 1;  
    	}  
    	finally {  
    	    System.out.println("finally block is run 
            before method returns.");
    	}
    }
}

　　

Running the code above gives us this output:

finally block is run before method returns.
1

　　

From the output above, you can see that the finally block is executed before control is returned to the “System.out.println(SomeClass.proveIt());” statement – which is why the “1” is output after the “finally block is run before method returns.” text.

 

Very unique situations when finally will not run after return

The finally block will not be called after return in a couple of unique scenarios: if System.exit() is called first, or if the JVM crashes.

What if there is a return statement in the finally block as well?

If you have a return statement in both the finally block and the try block, then you could be in for a surprise. Anything that is returned in the finally block will actuallyoverride any exception or returned value that is inside the try/catch block. Here is an example that will help clarify what we are talking about:

public static int getANumber(){
    try{
        return 7;
    } finally {
        return 43;
    }
}

　　

The code above will actually return the “43” instead of the “7”, because the return value in the finally block (“43″) will override the return value in the try block (“7″).

Also, if the finally block returns a value, it will override any exception thrown in the try/catch block. Here is an example:

public static int getANumber(){
    try{
        throw new NoSuchFieldException();
    } finally {
        return 43;
    }
}

　　

A return statement in the finally block is a bad idea

Running the method above will return a “43” and the exception in the try block will not be thrown. This is why it is considered to be a very bad idea to have a return statement inside the finally block.