How do you pass an executable block as a parameter in Java?

Question

Is there a way to pass an executable block as a parameter to a static method? Is it possible at all? For example I have this method

public static void someMethod(boolean flag, Block block1, BLock block2) {     //some other code     if(flag)         block1.execute();     else block2.execute();     //some other code } 

or something like that. It's actually more complicated than this, I just simplified the question. I am trying to refactor my project and I created a generic utility class that contains static methods that my classes use.

Answer 1

You can use Runnable objects:

public static void someMethod(boolean flag, Runnable block1, Runnable block2) {     //some other code     if(flag)         block1.run();     else block2.run();     //some other code } 

Then you can call it with:

Runnable r1 = new Runnable() {     @Override     public void run() {         . . .     } }; Runnable r2 = . . . someMethod(flag, r1, r2); 

EDIT (sorry, @Bohemian): in Java 8, the calling code can be simplified using lambdas:

someMethod(flag, () -> { /* block 1 */ }, () -> { /* block 2 */ }); 

You'd still declare someMethod the same way. The lambda syntax just simplifies how to create and pass the Runnables.