java高级反射之获取字段(三)

package com.jk.fs;

import java.lang.reflect.Constructor;

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

/**
*
* @author sx123
*
*/
public class ReflectzDemo {

   public static void main(String[] args) throws Exception {

       //getFieldDemo();
       getMethodDemo_3();
   }
   /**
   * 反射机制(获取Class中的字段)
   * @throws ClassNotFoundException
   * @throws NoSuchFieldException
   * @throws Exception
   */
   public static void getFieldDemo() throws ClassNotFoundException, NoSuchFieldException, Exception {
       Class clazz = Class.forName("com.jk.bean.Person");
       //Field field = clazz.getField("age");//只能获取公有的字段
       Field field =clazz.getDeclaredField("age");//只获取本类的所有的字段
       //对私有字段的访问取消权限检查暴力访问
       field.setAccessible(true);
       Object obj = clazz.newInstance();
       field.set(obj, 88);
       Object o = field.get(obj);
       System.out.println(o);
   }
   /**
   * 反射机制(获取Class中的方法)
   * 获取指定Class中的公共函数
   * @throws Exception
   */
   public static void getMethodDemo() throws Exception {
       Class clazz = Class.forName("com.jk.bean.Person");
       Method[] methods = clazz.getMethods();//获取的都是共有方法(public)
       methods = clazz.getDeclaredMethods();//只获取本类中所有方法，包含私有
       for(Method method:methods) {
           System.out.println(method);
       }
   }
   public static void getMethodDemo_2() throws Exception {
       Class clazz = Class.forName("com.jk.bean.Person");
       Method method = clazz.getMethod("show", null);//获取空参数一般方法
       // Object obj = clazz.newInstance();
       Constructor constructor = clazz.getConstructor(String.class,int.class);
       Object obj = constructor.newInstance("小明",32);
       method.invoke(obj, null);
   }
   public static void getMethodDemo_3() throws Exception{
       Class clazz = Class.forName("com.jk.bean.Person");
       Method method = clazz.getMethod("paramMethod", String.class,int.class);//获取空参数一般方法
       Object obj = clazz.newInstance();
       method.invoke(obj, "小强",43);
   }
}

java高级反射之获取字段(三)

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