反射（2）

得到Class类的几种方法

package com.reflection;/**
 * 测试Class类的创建方式有哪些
 * @author 长空扯淡
 */
public class Test02 {
    public static void main(String[] args) throws ClassNotFoundException {
        Person person = new Student();
        System.out.println(person.name);

        //方式一：通过对象获得
        Class c1 = person.getClass();
        System.out.println(c1.hashCode());

        //方式二：forName获得
        Class c2 = Class.forName("com.reflection.Student");
        System.out.println(c2.hashCode());

        //方式三：通过类名.class获得
        Class<Student> c3 = Student.class;
        System.out.println(c3.hashCode());

        //方式四：基本内置类型的包装类都有一个Type属性
        Class c4 = Integer.TYPE;
        System.out.println(c4);

        //获得父类类型
        Class c5 = c1.getSuperclass();
        System.out.println(c5);
    }
}

class Person{
    public String name;

    public Person(){}

    public Person(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                '}';
    }
}

class Student extends Person{
    public Student(){
        this.name = "学生";
    }
}

class Teacher extends Person{
    public Teacher(){
        this.name = "老师";
    }
}

所有类型的Class对象

package com.reflection;

import java.lang.annotation.ElementType;

//所有类型的class
public class Test03 {
    public static void main(String[] args) {
        Class c1 = Object.class;   //类
        Class c2 = Comparable.class;   //接口
        Class c3 = String[].class;   //一维数组
        Class c4 = int[][].class;    //二维数组
        Class c5 = Override.class;    //注解
        Class c6 = ElementType.class;    //枚举
        Class c7 = Integer.class;   //基本数据类型
        Class c8 = void.class;   //void
        Class c9 = Class.class;   //Class
//只要元素类型与维度一样，就是同一个Class
        int[] a = new int[10];
        int [] b = new int[100];
        System.out.println(a.getClass().hashCode());
        System.out.println(b.getClass().hashCode());
    }
}