《Java 核心技术 卷1》 笔记 第五章 继承（10）反射

5.7.4 反射对运行时对象分析

Field f = clazz.getField("fieldName");

Object v = f.get(obj);

public class Main {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
      Main solution = new Main();
      Test t = solution.new Test(3,5);
      System.out.println(t.getClass().getDeclaredField("a").get(t));
      System.out.println(t.getClass().getDeclaredField("b").get(t));
    }

    class Test{
         int a;
        private int b;
        public Test(int a,int b){
            this.a = a;
            this.b = b;
        }
    }
}

私有属性，需要开启访问权限：setAccessible()

public class Main {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
      Main solution = new Main();
      Test t = solution.new Test(3,5);
      System.out.println(t.getClass().getDeclaredField("a").get(t));
      Field fb = t.getClass().getDeclaredField("b");
      fb.setAccessible(true);
      System.out.println(fb.get(t));
      fb.setAccessible(false);
    }

    class Test{
         int a;
        private int b;
        public Test(int a,int b){
            this.a = a;
            this.b = b;
        }
    }
}

查看类中属性信息与子类属性信息：

类中当前属性，并打印当前属性信息；子类中当前属性，并打印当前属性信息，是基本类型（isPrimitive）的直接打印；

import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.HashSet;
import java.util.Set;

public class ObjectAnalyzer {
    private static Set