Can you set a method to a variable? [closed]

Question

Is it possible to do something like this in Java

private ? /* (I dont know what Class to use) */ shortcutToMethod = redundantMethod(game.getGraphics());

So instead of calling redundantMethod(game.getGraphics().doThisMethod());

I could just do shortCutToMethod.doThisMethod();

Is this possible?

Answer 1

In Java, there are various ways. If you take a look at java.util.function package, you can see

• Function: Takes one argument, produces one result
• Consumer: Takes one argument, produces nothing.
• BiConsumer: Takes two arguments, produces nothing.
• Supplier: Takes no argument, produces one result.
• Predicate: Boolean value function of one argument

You can used them as inputs for your method and execute it within.

Answer 2

Java 8 has introduced the idea of a Functional Interface, which allows you to essentially assign methods to variables. It includes a number of commonly-used interfaces as well.

Common examples:

• Consumer<T> - a method that takes in T and returns void
• Function<T, R> - a method that takes in T and returns R
• Supplier<R> - a method that takes no arguments and returns R
• Runnable - a method that takes no arguments and returns void
• Predicate<T> - a method that takes in T and returns boolean

In your case, you appear to be after a Runnable:

Runnable shortcutToMethod = () -> redundantMethod(game.getGraphics());
shortcutToMethod.run();