Java、Scala获取Class实例

Java获取Class实例的四种方式

package com.test;/**
* @description: TODO
* @author: HaoWu
* @create: 2020/7/22 10:39
*/
public class A {
public static void main(String[] args) throws ClassNotFoundException {
//1.类名.class
Class clazz1 = A.class;
//2.对象名.getClass()
A a = new A();
Class clazz2 = a.getClass();
//3.Class.forName(全类名)
Class clazz3 = Class.forName("com.test.A");
//4.通过类的加载器
ClassLoader classLoader = this.getClass().getClassLoader();
Class clazz4 = classLoader.loadClass("com.test.A");
}
}


Scala获取Class实例

classOf[A] 类A的类型

a.getClass 对象a的类型，多态情况获取的是对象的类型，不是父类类型

val a : A = new B
val type1_A = classOf[A].getName //com.bigdata.scala.day01.$08_Param$A
val type2_A = a.getClass.getName //com.bigdata.scala.day01.$08_Param$B class A
class B extends A