通过反射改变对象的属性

package ReflectTest;

public class Dog {

    private final String name;
    private final int sex;
    private final int weight;
    private final String type;

    public Dog(String name, int sex, int weight, String type) {
        this.name = name;
        this.sex = sex;
        this.weight = weight;
        this.type = type;
    }

    public String getName() {
        return name;
    }

    public int getSex() {
        return sex;
    }

    public int getWeight() {
        return weight;
    }

    public String getType() {
        return type;
    }

    @Override
    public String toString() {
        return "{\"name\":\"" + name + "\",\"sex\":\"" + sex + "\",\"weight\":\"" + weight + "\",\"type\":\"" + type + "\"} ";
    }
}

package ReflectTest;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;

public class Run {

    public static void main(String[] args) throws Exception {
        // 性别: 0:母, 1:公
        Dog dog = new Dog("点点", 0, 25, "哈士奇");
        System.out.println(dog.toString());
        Class<? extends Dog> clazz = dog.getClass();// 获取到对象对应的class对象
        Field[] fields = clazz.getDeclaredFields();//
        for (Field f : fields) {
            String fileName = f.getName();
            int m = f.getModifiers();
            String mStr = Modifier.toString(m);
            System.out.println(fileName + " 属性:" + mStr);
        }

        // 把上面已经创建好的狗狗的名字改为：大大
        Field nameField = clazz.getDeclaredField("name");// 获取私有成员变量:name
        nameField.setAccessible(true);// 设置操作权限为true
        nameField.set(dog, "大大");
        Field typeField = clazz.getDeclaredField("type");
        typeField.setAccessible(true);
        typeField.set(dog, "金毛");
        System.out.println(dog.toString());
    }

}