Java-syntax for explicitly specifying generic arguments in method calls

Question

What is the syntax for explicitly giving the type parameters for a generic Java method?

Answer 1

A good example from java.util.Collection of specifying a generic method which defines its own generic type is Collection.toArray where the method signature looks like:

 T[] toArray(T[] a);

This declares a generic type T, which is defined on method call by the parameter T[] a and returns an array of T's. So the same instance could call the toArray method in a generic fashion:

Collection collection = new ArrayList();
collection.add(1);
collection.add(2);

// Call generic method returning Integer[]
Integer[] ints = collection.toArray(new Integer[]{});

// Call generic method again, this time returning an Number[] (Integer extends Number)
Number[] nums = collection.toArray(new Number[]{});

Also, see the java tutorial on generic type parameters.