泛型.

写了个例子区分下泛型通配符容易弄错的地方.

import java.util.List;


public class Box<T> {

	private T object;
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
           Box<Integer> bs = new Box<Integer>();
           
           bs.set(10);
           
           String des = bs.Get("ffff"); //generic type of method
           
           Number desno = bs.Get(new Integer(1));//generic type of method
           
           System.out.println(des.toString());
           
           System.out.println(desno.toString());
           
           System.out.println(bs.get().toString()); // generic type of class
	}

	/**
	 * 返回的T就是从类的T推定.
	 * @return
	 */
	public   T get()
	{
		return  object;
	}
	
	public  void set(T obj)
	{
		object =  obj;
	}
	/**
	 * 返回的T由入参那个T 推定.
	 * @param srcobj
	 * @return
	 */
	public <T> T Get(T srcobj)
	{
		return srcobj;
		
	}
	
}