汎用パラメータ

public class Animal {
	private String id;
	private String name;
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
}

public class Cat extends Animal implements Comparable<Cat>{
	public int compareTo(Cat arg0) {
		return this.getId().compareTo(arg0.getId());
	}

}

public class Dog extends Animal implements Comparable<Dog> {
	public int compareTo(Dog arg0) {
		return this.getId().compareTo(arg0.getId());
	}
}

public  class demo<E> 
{
	List rsList=new ArrayList();
	public E getById(E o)
	{
		System.out.println(o);
		return o ;
	}
}

public class Demo1 {
	public <E extends Animal>void getByid(List<E> e)
	{     		
	}
	public void getByidL(List<Animal> list)
	{	
	}
}

public class DemoTest {
	public static void main(String[] args) {
		
		System.out.println("***********");
		demo<String> demo=new demo<String>();
		demo.getById("ddddd");
	}
	public void test()
	{
		List<Dog> list=new ArrayList<Dog>();
		List<Animal>list1=new ArrayList<Animal>();
		Demo1 demo=new Demo1();
		demo.getByidL(list1);// Animal
		demo.getByid(list);// Animal  
		demo.getByid(list1);
//		demo.getByidL(list);//this is wrong because List<Dog> is not List<Animal>
		
	}
	/**
	 *  name 
	 * @author wei
	 *
	 */
	class NameCompare implements Comparator<Cat>
	{
		public int compare(Cat arg0, Cat arg1) {
			return arg0.getName().compareTo(arg1.getName());
		}
	}
	/**
	 *  id 
	 * @author wei
	 *
	 */
	class IdCompare implements Comparator<Cat>
	{
		public int compare(Cat arg0, Cat arg1) {
			return arg0.getId().compareTo(arg1.getId());
		}
	}
public void test1()
{
	List<Cat>rslist=new ArrayList<Cat>();
	NameCompare nameCompare=new NameCompare();
    Collections.sort(rslist, nameCompare);// 
}
}