调用运行时类的指定结构：属性、方法、构造器

package day3;

import org.junit.Test;

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

//调用运行时类的指定结构：属性、方法、构造器
public class ReflectionDemo2 {
@Test
public void testField() throws Exception {
Class c1= Person.class;
Person p1=(Person)c1.newInstance();
//get，获取运行时类及其父类的public的属性
Field age = c1.getField("age");
age.set(p1,123);
System.out.println((int)age.get(p1));

    //getDeclared，获取运行时类任意权限的属性
    Field name = c1.getDeclaredField("name");
    //把非public的属性设置为可访问
    name.setAccessible(true);
    name.set(p1,"Tom");
    System.out.println((String)name.get(p1));
}

@Test
public void testMethod() throws Exception {
    Class c1= Person.class;
    Person p1=(Person)c1.newInstance();
    //通过方法名和形参列表，获取方法
    Method show = c1.getDeclaredMethod("showNation", String.class);
    show.setAccessible(true);
    System.out.println((String) show.invoke(p1,"China"));

    //调用静态方法
    Method showDetail = c1.getDeclaredMethod("showDetail");
    showDetail.setAccessible(true);
    //调用者为运行时类
    showDetail.invoke(c1);
    showDetail.invoke(null);
}

}

class Person {
private String name;
public int age;

public Person(){
}
public Person(String name, int age) {
    this.name = name;
    this.age = age;
}
private Person(String name) {
    this.name = name;
}
public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int getAge() {
    return age;
}

public void setAge(int age) {
    this.age = age;
}
@Override
public String toString() {
    return "姓名："+ name + "，年龄：" + age;
}
public String show(){
    return this.name+" , "+this.age;
}
private String showNation(String nation){
    return "我来自"+nation;
}
private static void showDetail(){
    System.out.println("谁是最可爱的人");
}

}