java反射获取属性和方法_JAVA_编程开发_程序员俱乐部

class="java" name="code">---测试类
package com.test.jse.invoke;

public class MyClass {
	public String n = "MyClass公有变量"; 
	private String m = "MyClass私有变量";
	
	public MyClass(){
		System.out.println("MyClass无参公有构造方法");
	}
	
	private MyClass(int n,String name){
		System.out.println("MyClass有参私有构造方法"+"\t名字："+name+"\t编号："+n);
	}
	
	public void say(){
		System.out.println("MyClass类的无参公有一般方法---say()");
	}
	
	private void tell(String name){
		System.out.println("MyClass类的一般有参私有方法----private tell()");
	}
}

----利用反射获取类中属性和调用类中的方法
package com.test.jse.invoke;

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

public class People {
	public static void main(String[] args) {
		try {
			Class clazz = Class.forName("com.test.jse.invoke.MyClass");//反射出来的类clazz
			MyClass myClass =(MyClass)clazz.newInstance();//MyClass类无参数公有构造函数
			
			Constructor constructor = clazz.getDeclaredConstructor(new Class[]{int.class,String.class});
		constructor.setAccessible(true);//设置查看私有方法的权限
		MyClass myclass2 = (MyClass)constructor.newInstance(1,"张三");
			
		System.out.println(clazz.getField("n").get(myClass));
			
		Field field = clazz.getDeclaredField("m");//定义m变量
		field.setAccessible(true);
		System.out.println(field.get(myClass));
			
		Method method_say = clazz.getMethod("say"); //先查询定位到公有say()方法
		method_say.invoke(myClass);		//再执行say()方法
			
		Method method = clazz.getDeclaredMethod("tell", new Class[]{String.class }); //定义方法属性
		method.setAccessible(true);
		method.invoke(myClass,"张三");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (NoSuchMethodException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (InvocationTargetException e) {
			e.printStackTrace();
		} catch (NoSuchFieldException e) {
			e.printStackTrace();
		}
	}
}