14 性能对比分析

package annotate;


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

// 性能检测
public class Test12 {
    // 1. 普通调用
    public static void test01(){
        long startTime=System.currentTimeMillis();
        for (int i = 0; i < 1000000000; i++) {
            new Body().getAge();
        } // 执行10亿次
        long endTime=System.currentTimeMillis();
        System.out.println("普通调用:"+(endTime-startTime)+"ms");
    }
    // 2. 反射调用
    public static void test02() throws Exception {
        Class c1= Body.class;
        Method method=c1.getMethod("getAge",null);
        long startTime=System.currentTimeMillis();
        for (int i = 0; i < 1000000000; i++) {
            method.invoke(new Body(),null);
        } // 执行10亿次
        long endTime=System.currentTimeMillis();
        System.out.println("反射调用:"+(endTime-startTime)+"ms");
    }
    // 3. 反射调用 + 关闭安全检测
    public static void test03() throws Exception {
        Class c1= Body.class;
        Method method=c1.getMethod("getAge",null);
        method.setAccessible(true);  // 关闭安全检测
        long startTime=System.currentTimeMillis();
        for (int i = 0; i < 1000000000; i++) {
            method.invoke(new Body(),null);
        } // 执行10亿次
        long endTime=System.currentTimeMillis();
        System.out.println("反射调用 + 关闭安全检测:"+(endTime-startTime)+"ms");
    }

    public static void main(String[] args) throws Exception {
        test01();
        test02();
        test03();
    }
}

class Body{
    private int age;
    private int id;
    private String name;

    public Body(){}
    public Body(int age, int id, String name) {
        this.age = age;
        this.id = id;
        this.name = name;
    }

    public int getAge(){
        return age;
    }
    public void setAge(int age){
        this.age=age;
    }
    public void say(){}
}