4、java反射机制例子

java反射机制例子:

1.新建Calculator.java

package invoke;

public class Calculator {

    public int add(int a, int b) {

        return a + b;

    }

}

2.新建CalculatorTest.java,作为测试,采用反射机制获取到Calculator的add方法:

package invoke;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import invoke.Calculator;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;



public class CalculatorTest {



    @Before

    public void setUp() throws Exception {

    }



    @After

    public void tearDown() throws Exception {

    }



    @Test

    public void testAdd() throws ClassNotFoundException, SecurityException, NoSuchMethodException, IllegalArgumentException, IllegalAccessException, InvocationTargetException {

        //方法中所需要的参数

        Integer[] input = new Integer[]{new Integer(1), new Integer(2)};

        Class clazz = Class.forName("invoke.Calculator");

        //获取add方法的method

        @SuppressWarnings("unchecked")

        Method method = clazz.getMethod("add", new Class[]{int.class, int.class});

        Integer output = (Integer) method.invoke(new Calculator(), input);

        System.out.println("1 + 2 =" + output.intValue());

    }

}

3.运行结果:1 + 2 = 3

来自为知笔记(Wiz)