性能对比分析

Posted 2023-03-26 123456dh

package edu.wtbu;

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

//分析性能问题
public class Demo01 
    public static void main(String[] args) throws InvocationTargetException, NoSuchMethodException, IllegalAccessException 
        Demo01 demo01 = new Demo01();
        demo01.text1();
        demo01.text2();
        demo01.text3();
    
    //普通方法调用
    public void  text1()
        User user = new User();
        long start = System.currentTimeMillis();
        for (int i = 0; i <1000000000 ; i++) 
            user.getName();
        
        long end = System.currentTimeMillis();
        System.out.println("执行时间"+(end-start)+"ms");
    

    //反射方法调用
    public void  text2() throws NoSuchMethodException, InvocationTargetException, IllegalAccessException 
        User user = new User();
        Class<? extends User> c1 = user.getClass();
        Method getName = c1.getDeclaredMethod("getName",null);
        long start = System.currentTimeMillis();
        for (int i = 0; i <1000000000 ; i++) 
            getName.invoke(user,null);
        
        long end = System.currentTimeMillis();
        System.out.println("执行时间"+(end-start)+"ms");
    

    //反射方法调用  关闭检测
    public void  text3() throws InvocationTargetException, IllegalAccessException, NoSuchMethodException 
        User user = new User();
        Class<? extends User> c1 = user.getClass();
        Method getName = c1.getDeclaredMethod("getName",null);
        getName.setAccessible(true);
        long start = System.currentTimeMillis();
        for (int i = 0; i <1000000000 ; i++) 
            getName.invoke(user,null);
        
        long end = System.currentTimeMillis();
        System.out.println("执行时间"+(end-start)+"ms");