反射案例 -复制一个对象

Posted 2021-01-21 言西早石头侠

package com.iotek.classtype;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

public class FansheDemo {
    public static void main(String[] args) {
        // 2,生成一个学生对象(被复制的那个对象,原对象)
        Student student = new Student(1, "谭磊", 20);
        try {
            Student student2=(Student)ObjectCopuUtil.copyObject(student);
            System.out.println("复制成功");
           System.out.println(student2.toString());
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        

    }
}

// 创建一个拷贝对象的工具类,内部提供一个拷贝方法 接收原对象
class ObjectCopuUtil {
    public static Object copyObject(Object object) throws Exception {
        // 3.获取Student对所对应类型的class对象(也就是Student这个类所对应的class对象)
        Class<?> class1 = object.getClass();
        // 4.通过class对象的newInstance()方法来构建一个目标对象
        Object objres = class1.newInstance();
        // 5.获取class对象的get和set方法
        for (Field fieldt : class1.getDeclaredFields()) {
                /*//得到属性所对应的get和set方法 
                 String setMethodName="set"
                +fieldt.getName().substring(0, 1).toUpperCase()
                 +fieldt.getName().substring(1);
                 String getMethodName="get"
                        +fieldt.getName().substring(0, 1).toUpperCase()
                         +fieldt.getName().substring(1);
                 //调用原对象的get方法获得属性值
                 Method getmethod=class1.getDeclaredMethod(getMethodName, new Class[] {});
                 Object value=getmethod.invoke(object, new Object[] {});
                 
                 //调用目标对象的set方法来给属性赋值=
                 Method setmethod=class1.getDeclaredMethod(setMethodName, new Class[] {fieldt.getType()});
                 setmethod.invoke(object, new Object[] {value});*/
                 
            //直接获取原对象属性的值
            fieldt.setAccessible(true);
            Object value=fieldt.get(object);
            fieldt.set(objres, value);
        }

        return objres;

    }
}

// 1,声明一个学生类
class Student {
    private int id;
    private String name;
    private int age;

    public Student() {
        super();
    }

    public Student(int id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
    }

}