反射注解之通过Class对象获得类的内部结构

获得类内部结构的代码如下

package com.loubin;

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

public class Main {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException, NoSuchMethodException {
        Class c = User.class;
        String name = c.getName();
        System.out.println(name);
        System.out.println("获取所有属性-------------------------------");
        Field[] fields = c.getDeclaredFields();
        for (Field field : fields) {
            System.out.println(field.getName());
        }
        System.out.println("获取指定属性-----------------------------------");
        Field field = c.getDeclaredField("name");
        System.out.println(field.getName());
        System.out.println("获取所有方法----------------------------------");
        Method[] methods = c.getDeclaredMethods();
        for (Method method : methods) {
            System.out.println(method.getName());
        }
        System.out.println("获取指定方法----------------------------------");
        Method method = c.getDeclaredMethod("getName");
        System.out.println(method.getName());
        System.out.println("获取无参构造器------------------------------------");
        Constructor constructor = c.getDeclaredConstructor();
        System.out.println(constructor.getName());
        System.out.println("获取有参构造器-----------------------------------");
        Constructor constructor1 = c.getDeclaredConstructor(String.class, int.class);
    }
}


class User{
    String  name;
    int age;

    public User() {
    }

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

    public int getAge() {
        return age;
    }

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

    public String getName() {
        return name;
    }

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

 

测试结果如下

 还有getField和getMethod方法我没写，这两个方法只能获得public属性和public方法