How to determine by reflection if the method returns 'void'

Question

I have a java.lang.reflect.Method object and I would like to know if it returns a void type.

I checked Javadocs and there is a getReturnType() method that returns a class object. The fact is that they do not say what the return type will be if the method is invalid.

Thank!

Answer 1

 if( method.getReturnType().equals(Void.TYPE)){ out.println("It does"); } 

Quick example:

 $cat X.java import java.lang.reflect.Method; public class X { public static void main( String [] args ) { for( Method m : X.class.getMethods() ) { if( m.getReturnType().equals(Void.TYPE)){ System.out.println( m.getName() + " returns void "); } } } public void hello(){} } $java X hello returns void main returns void wait returns void wait returns void wait returns void notify returns void notifyAll returns void 

Answer 2

method.getReturnType() returns void.class / Void.TYPE .

Answer 3

It returns java.lang.Void.TYPE .

Answer 4

 method.getReturnType()==void.class √ method.getReturnType()==Void.Type √ method.getReturnType()==Void.class X 

Answer 5

There is another, perhaps less traditional way:

public boolean doesReturnVoid(Method method) { if (void.class.equals(method.getReturnType())) return true; }