获得类的运行时结构

获得类的运行时结构

代码如下

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

//获得类的信息
public class Test08 {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException, NoSuchMethodException {
        Class c1 = Class.forName("com.lu.reflection.User");

//        User user = new User();
//        c1 = user.getClass();

        //获得类的名字
        System.out.println(c1.getName());  //获得包名 + 类名
        System.out.println(c1.getSimpleName()); //获得类名

        //获得类的属性
        System.out.println("=====================");
        Field[] fields = c1.getFields();  //只能找到public

      fields = c1.getDeclaredFields(); //找到全部的属性
        for (Field field : fields) {
            System.out.println(field);
        }

      //获得指定属性的值
        Field name = c1.getDeclaredField("name");
        System.out.println(name);


        //获得类的方法
        System.out.println("=====================");
        Method[] methods = c1.getMethods(); //获得本类及其父类的全部public方法
        for (Method method : methods) {
            System.out.println("正常的："+method);
        }
        methods = c1.getDeclaredMethods();  //获得本类的所有方法
        for (Method method : methods) {
            System.out.println("getDeclaredMethods："+method);
        }

        //获得指定方法
        //重载，所以需要参数
        System.out.println("=====================");
        Method getName = c1.getMethod("getName", null);
        Method setName = c1.getMethod("setName", String.class);
        System.out.println(getName);
        System.out.println(setName);

        //获得指定的构造器
        System.out.println("=====================");
        Constructor[] constructors = c1.getConstructors(); //获得public方法
        for (Constructor constructor : constructors) {
            System.out.println(constructor);
        }
        constructors = c1.getDeclaredConstructors();    //获得本类的全部方法
        for (Constructor constructor : constructors) {
            System.out.println("#"+constructor);
        }

        //获得指定的构造器
        Constructor declaredConstructor = c1.getDeclaredConstructor(String.class, int.class, int.class);
        System.out.println("指定："+declaredConstructor);
    }
}