[SOLVED] Java common Try/Finally block around different code blocks

Java common Try/Finally block around different code blocks - code style

I have the same if() { try { < SOME CODE > } finally { } } else {} block that I use in 3 methods.

The only thing that's different in each method is < SOME CODE >.

Are there any coding patterns that I can use to "DRY" my code? Ideally would like to extract the if() { try { } finally { } } else {} to some common structure and pass the < SOME CODE > to it. Is that possible in Java?

Thanks

Solution

You could introduce a common method to factor out the common part.

Then according to your requirements you could do :

1) if the 3 methods are in the same class : extracting each set of statements of the try bodies in 3 specific methods and pass this method as a Runnable parameter in the common method.
For example :

public void commonMethod(Runnable methodToInvoke){

     if() {
            try { methodToInvoke.run() } finally { } 
     } 
     else {}
}

And call it by passing the 3 extracted methods :

commonMethod(this::methodFoo);
commonMethod(this::methodBar);
commonMethod(this::methodFooBar);

2) if the 3 methods are in distinct classes : introducing an interface that the 3 classes will implement and make the common method accept a parameter of this interface.

For example with a Processing interface introduced :

public void commonMethod(Processing processing){

     if() {
            try { processing.doThat() } finally { } 
     } 
     else {}
}

And call it by passing the 3 implementations of the Processing interface :

commonMethod(foo);
commonMethod(bar);
commonMethod(fooBar);