java注解和反射（反射：第一部分）

 

 

 

 

 

 

 

 

/**
 * 获取class类实例的方式
 */
public class Test04 {
    public static void main(String[] args) throws ClassNotFoundException {
        Persion persion = new Teacher();
        Persion persion2 = new Teacher();
        System.out.println("这个人是"+persion.name);//这个人是老师

        //方式一、通过对象获得
        Class c1 = persion.getClass();
        Class c12 = persion2.getClass();
        System.out.println(c1.hashCode());//460141958
        System.out.println(c12.hashCode());//460141958
        System.out.println("========================================");

        ///方式二、通过类名获取
        Class c2 = Teacher.class;
        System.out.println(c2.hashCode());//460141958

        //方式三、forname获取
        Class c3 = Class.forName("javaBasic.annotation.Teacher");
        System.out.println(c3.hashCode());//460141958

        //前三种方式获得的class类实例的hashcode一致，表明一个类只有一个class类实例。

        //方式四、基本类型的包装类都有一个Type类型
        Class c4 = Integer.TYPE;
        System.out.println(c4.hashCode());//1163157884

        //获得父类类型
        Class superclass = c1.getSuperclass();
        System.out.println(superclass);//class javaBasic.annotation.Persion

    }
}
class Persion{
    public String name;

    @Override
    public String toString() {
        return "Persion{" +
                "name='" + name + '\'' +
                '}';
    }
}
class Teacher extends Persion{
    public Teacher(){
        this.name = "老师";
    }
}
class Student extends Persion{
    public Student(){
        this.name = "学生";
    }
}