java通過反射獲取Java對象屬性值

說明：

　　作為反射工具類，通過對象和屬性的名字獲取對象屬性的值，如果在當前對象屬性沒有找到，依次向上收集所有父類的屬

性，直到找到屬性值，沒有找到返回null；

代碼：

　　1.classUtil

package com.example.demo.utill;

import java.lang.reflect.Field;

/**
 * description: TODO
 * date: 2020/3/24 0024 下午 21:32
 *
 * @author : Administrator
 * @since : 1.0
 **/
public class ClassUtil {

    public static Object getPropertyValue(Object obj, String propertyName) throws IllegalAccessException {
        Class<?> Clazz = obj.getClass();
        Field field;
        if ((field = getField(Clazz, propertyName)) == null)
            return null;
        field.setAccessible(true);
        return field.get(obj);
    }

    public static Field getField(Class<?> clazz, String propertyName) {
        if (clazz == null)
            return null;
        try {
            return clazz.getDeclaredField(propertyName);
        } catch (NoSuchFieldException e) {
            return getField(clazz.getSuperclass(), propertyName);
        }
    }
}

　　2.測試類和介面

package com.example.demo.utill;

/**
 * description: TODO
 * date: 2020/3/24 0024 下午 21:50
 *
 * @author : Administrator
 * @since : 1.0
 **/
public class Person {
    private String age;

    public String getAge() {
        return age;
    }

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

package com.example.demo.utill;

/**
 * description: TODO
 * date: 2020/3/24 0024 下午 21:42
 *
 * @author : Administrator
 * @since : 1.0
 **/
public class User  extends Person{
    private String name ;

    public String getName() {
        return name;
    }

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

3.測試

package com.example.demo.utill;

/**
 * description: TODO
 * date: 2020/3/24 0024 下午 21:41
 *
 * @author : Administrator
 * @since : 1.0
 **/
public class Test {
    public static void main(String[] args) throws IllegalAccessException {
        User u = new User();
        u.setName("張三");
        u.setAge("20");
        Object o = ClassUtil.getPropertyValue(u,"ag1e");
        System.out.println(o);
    }
}
// outPut：null