Java中泛型之类型通配符(?)

实体类

package cn.xy.model;

/**
* 生物类
* @author xy
*
*/
public class Living
{
private String name;

public Living(String name)
{
super();
this.name = name;
}

public String getName()
{
return name;
}

public void setName(String name)
{
this.name = name;
}

@Override
public String toString()
{
return name;
}
}

/**
* 动物类
* @author xy
*
*/
public class Animal extends Living
{
public Animal(String name)
{
super(name);
}
}

/**
* 猫类
* @author xy
*
*/
public class Cat extends Animal
{
public Cat(String name)
{
super(name);
}
}

/**
* 狗类
* @author xy
*
*/
public class Dog extends Animal
{
public Dog(String name)
{
super(name);
}
}

测试类1

import java.util.ArrayList;
import java.util.List;
import cn.xy.model.Animal;
import cn.xy.model.Cat;
import cn.xy.model.Dog;
import cn.xy.model.Living;

public class Test
{

/**
* 虽Cat和Dog是Animal的子类，但List和List不是List的子类，直接为该方法传入List和List编译

* 会错误。如List不是List