How to asynchronously call a method in Java

Question

I've been looking at Go's goroutines lately and thought it would be nice to have something similar in Java. As far as I've searched the common way to parallelize a method call is to do something like:

final String x = "somethingelse"; new Thread(new Runnable() {            public void run() {                 x.matches("something");                  } }).start(); 

Thats not very elegant. Is there a better way of doing this? I needed such a solution in a project so I decided to implement my own wrapper class around a async method call.

I published my wrapper class in J-Go. But I don't know if it is a good solution. The usage is simple:

SampleClass obj = ... FutureResult<Integer> res = ... Go go = new Go(obj); go.callLater(res, "intReturningMethod", 10);         //10 is a Integer method parameter //... Do something else //... System.out.println("Result: "+res.get());           //Blocks until intReturningMethod returns 

or less verbose:

Go.with(obj).callLater("myRandomMethod"); //... Go away if (Go.lastResult().isReady())                //Blocks until myRandomMethod has ended     System.out.println("Method is finished!"); 

Internally I'm using a class that implements Runnable and do some Reflection work to get the correct method object and invoking it.

I want some opinion about my tiny library and on the subject of making async method calls like this in Java. Is it safe? Is there already a simplier way?

Answer 1

I just discovered that there is a cleaner way to do your

new Thread(new Runnable() {     public void run() {         //Do whatever     } }).start(); 

(At least in Java 8), you can use a lambda expression to shorten it to:

new Thread(() -> {     //Do whatever }).start(); 

As simple as making a function in JS!

Answer 2

Java 8 introduced CompletableFuture available in package java.util.concurrent.CompletableFuture, can be used to make a asynch call :

CompletableFuture.runAsync(() -> {     // method call or code to be asynch. });