package reflection2;

import static org.junit.Assert.assertArrayEquals;

import java.lang.reflect.Constructor;

import java.lang.reflect.Field;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import org.junit.jupiter.api.Test;

import reflection1.Person;

/*

 * 调用运行时类中指定的结构：属性，方法，构造器

 * */

public class ReflectionTest {

    /*

     *

     *

     * */

    @Test

    public void test1() throws NoSuchFieldException, SecurityException, InstantiationException, IllegalAccessException {

        Class clazz = Person.class;

        //创建运行时类对象

        Person person = (Person)clazz.newInstance();

        //获取指定变量名的属性

        Field name = clazz.getDeclaredField("name");

        //将权限修改为可获得

        name.setAccessible(true);

        //设置当前对象的属性值:set()方法:参数1：指明设置哪个对象的属性，参数2：将属性设置为多少

        name.set(person, "Tom");

        /*

         * 获取当前属性值get():参数1：获取哪个对象的属性值

         * */

        int pAge = (int)name.get(person);

        System.out.println(pAge);

    }

    /*

     * 操作运行时类中指定的方法

     * */

    @Test

    public void test2() throws InstantiationException, IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException {

        Class clazz = Person.class;

        //创建运行时类对象

        Person person = (Person)clazz.newInstance();

        //获取指定的某个方法

        //参数1：指明获取方法的名称，参数2：指明获取方法的形参列表

        Method show = clazz.getDeclaredMethod("show", String.class);

        //将权限改为可访问

        show.setAccessible(true);

        //invoke():参数1：方法调用者 参数2：给方法形参赋值的实参

        //返回值 为调用的方法的返回值

        String nation = (String)show.invoke(person,"CHN");

        System.out.println(nation);

        System.out.println("*********************调用静态方法**********************");

        Method showDesc = clazz.getDeclaredMethod("showDesc");

        showDesc.setAccessible(true);

        //直接用这个类去调用就行

        showDesc.invoke(Person.class);

    }

    /*

     * 调用运行时类的指定的构造器

     * */

    @Test

    public void test3() throws NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {

        Class clazz = Person.class;

        //获取指定的构造器:参数：指明构造器的参数列表

        Constructor constructor = clazz.getDeclaredConstructor(String.class);

        //将权限改为可访问

        constructor.setAccessible(true);

        Person person = (Person)constructor.newInstance("Tom");

        System.out.println( person);

    }

}