Java 注解与反射（五）反射性能对比分析

Java 注解与反射（五）反射性能对比分析

代码

package com.zzz.reflection;

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

public class Test03 {
    public static void test01(){
        User user = new User();     //普通方式调用方法十亿次，查看运行时间
        long startTime = System.currentTimeMillis();

        for (int i = 0; i < 1000000000; i++) {
            user.getName();
        }

        long endTime = System.currentTimeMillis();
        System.out.println("普通方式执行10亿次："+(endTime-startTime)+"ms");
    }

    public static void test02() throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
        User user = new User();
        Class c1 = user.getClass();     //反射方式调用方法十亿次，查看运行时间

        Method getName = c1.getDeclaredMethod("getName", null);

        long startTime = System.currentTimeMillis();

        for (int i = 0; i < 1000000000; i++) {
            getName.invoke(user,null);
        }

        long endTime = System.currentTimeMillis();
        System.out.println("反射方式执行10亿次："+(endTime-startTime)+"ms");
    }

    public static void test03() throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
        User user = new User();
        Class c1 = user.getClass();     //反射关闭检测调用方法十亿次，查看运行时间

        Method getName = c1.getDeclaredMethod("getName", null);
        getName.setAccessible(true);
        long startTime = System.currentTimeMillis();

        for (int i = 0; i < 1000000000; i++) {
            getName.invoke(user,null);
        }

        long endTime = System.currentTimeMillis();
        System.out.println("关闭检测执行10亿次："+(endTime-startTime)+"ms");
    }

    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException {
        test01();
        test02();
        test03();
    }
}

结果