Generic methods for Java __java

Article reference from: http://www.cnblogs.com/iyangyuan/archive/2013/04/09/3011274.html

There are generic methods and generic classes.

Generics similar to the following code definitions are generic methods:

Package com.test.GenericTest;

Import java.util.ArrayList;
Import java.util.List;

Package com.test.GenericTest;

Import java.util.ArrayList;
Import java.util.List;

public class genericfoo<t>
{
	private T value;

	Public T GetValue ()
	{return
		value;
	}

	public void SetValue (T value)
	{
		this.value = value;
	}
	
	public static void Main (string[] args)
	{
		genericfoo<string> foo1 = new genericfoo<string> ();
		
		list<string>  list = new arraylist<string> ();
		
		
		Foo1.setvalue ("HelloWorld");
		
		System.out.println (Foo1.getvalue ());
		
		
	}

The preceding code defines a genericfoo<string> class.

A generic method that resembles the way defined below

Public <T> t[] ToArray (t[] a) {
        if (A.length < size)
            //Make a new array of A's runtime type, but my cont Ents: Return
            (t[]) arrays.copyof (elementdata, size, A.getclass ());
	System.arraycopy (elementdata, 0, a, 0, size);
        if (a.length > Size)
            a[size] = null;
        return A;
    }

return type t[] must precede <T> declare as generic method.

A generic class that indicates the specific type of a generic when instantiating a class, and a generic method that indicates the specific type of the generic when the method is invoked. Note: The generic method invocation indicates what type of generic t is.

A generic class is such as arraylist<string> list = new ArrayList () that indicates the type of the generic t when the class is initialized. This is the declaration of a generic class.