package com.jalja.org.jms.test01;

import java.util.Date;

public class User {

    private Integer id;

    private String name;

    private Date time;

    public User() {

        super();

    }

    public User(String name, Date time) {

        super();

        this.name = name;

        this.time = time;

    }

    public User(Integer id, String name, Date time) {

        super();

        this.id = id;

        this.name = name;

        this.time = time;

    }

    public Integer getId() {

        return id;

    }

    public void setId(Integer id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public Date getTime() {

        return time;

    }

    public void setTime(Date time) {

        this.time = time;

    }

}

package com.jalja.org.jms.test01;

public class UserVO extends User{

    private int sex;

    public int getSex() {

        return sex;

    }

    public void setSex(int sex) {

        this.sex = sex;

    }

}

package com.jalja.org.jms.test01;

import java.lang.reflect.Field;

import java.util.Date;

public class CopyObj {

    /**

     * 我们的业务是需要在现有的类上扩展一些属性供视图层使用

     * 1、在原有类上扩展一些属性也可以实现，但这样需要在别人的代码中直接更改，个人认为不是很好。

     * 2、写一个扩展类 UserVO 继承原类  User

     * @param args

     * @throws IllegalArgumentException

     * @throws IllegalAccessException

     */

    public static void main(String[] args) throws IllegalArgumentException, IllegalAccessException {

        User user=new User("2131",new Date());

        //将父类强转为子类出现异常Exception in thread "main" java.lang.ClassCastException:

        //UserVO vo1=(UserVO) user;

        //vo1.setSex(0);

        UserVO vo2=(UserVO) copyObj(user,new UserVO());

        vo2.setSex(0);

        System.out.println(vo2.getName());

    }

    /** 子对象copy父对象的属性值

     *  copyObj 继承 targetObj

     * @param targetObj  被copy的目标对象

     * @param copyObj  copy后的对象

     * @throws IllegalAccessException

     * @throws IllegalArgumentException

     */

    public static <T> T copyObj(T targetObj,T copyObj ) throws IllegalArgumentException, IllegalAccessException{

        Field [] fields=targetObj.getClass().getDeclaredFields();

        Field [] fieldsvo=copyObj.getClass().getSuperclass().getDeclaredFields();

        for(Field f:fields){

            f.setAccessible(true);

            for(Field f2:fieldsvo){

                f2.setAccessible(true);

                if(f.get(targetObj)!=null&& f.getName().toString().equals(f2.getName().toString())){

                    f2.set(copyObj,f.get(targetObj)) ;

                }

             }

        }

        return copyObj;

    }

}