reflect reflection technique

Disclaimer: This article is a blogger original article, shall not be reproduced without the bloggers allowed. https://blog.csdn.net/huoguang_/article/details/89236376

Reflective mode

package reflect;

/*
* @Title：通过反射构建对象，没有参数的类的反射生成的对象
*/
public class ReflectServiceImpl {
	public void sayHello(String name) {
		System.err.println("Hello " + name);
	}
	
	/*
	* @Description：生成对象并返回对象
	* @param：无
	* @return：ReflectServiceImpl对象
	*/
	public ReflectServiceImpl getInstance(){
		ReflectServiceImpl object = null;
		try {
			object = (ReflectServiceImpl) Class.forName("reflect.ReflectServiceImpl").newInstance();
		} catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
			e.printStackTrace();
		}
		
		return object;
	}
}

 

package reflect;

import java.lang.reflect.InvocationTargetException;

/*
* @Title：通过反射构建对象，有参数的类的反射生成的对象
*/
public class ReflectServiceImpl2 {
	private String name;

	public ReflectServiceImpl2(String name) {
		this.name = name;
	}

	public void sayHello() {
		System.err.println("hello " + name);
	}
	
	public ReflectServiceImpl2 getInstance() {
	    ReflectServiceImpl2 object = null;
	    try {
			object = (ReflectServiceImpl2) Class.forName("reflect.ReflectServiceImpl2").getConstructor(String.class).newInstance("张三");
		} catch (InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException
				| NoSuchMethodException | SecurityException | ClassNotFoundException e) {
			e.printStackTrace();
		}
	    
	    return object;
	}
}

 

test

package test;

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

import reflect.ReflectServiceImpl;

public class ReflectTest {
	public static void main(String[] args) {
	}
	
	public Object reflect() {
		ReflectServiceImpl object = null;
		try {
			//通过反射生成对象
			object = (ReflectServiceImpl) Class.forName("reflect.ReflectServiceImpl").newInstance();
			
			//获得反射的方法对象
			Method method = object.getClass().getMethod("sayHello", String.class);
			
			//反射方法
			method.invoke(object, "张三");
		} catch (NoSuchMethodException | SecurityException | ClassNotFoundException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | InstantiationException ex) {
			ex.printStackTrace();
		}
		return object;
	}
}