Java注解与反射（六）

package refection;
 public class Test06 {
     public static void main(String[] args) throws ClassNotFoundException {
         // 获取系统的类加载器
         ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader();
         System.out.println(systemClassLoader);
         // 获取系统类加载器的父类加载器 ---> 扩展类加载器
         ClassLoader parent =systemClassLoader.getParent();
         System.out.println(parent);
         // 获取扩展类加载器的父类加载器 ---> 根加载器（C/c++）
         ClassLoader parent1 = parent.getParent();
         System.out.println(parent1);                        // 获取不到，返回值位null
         // 获取当前类加载器
         ClassLoader classLoader = Class.forName("refection.Test06").getClassLoader();
         System.out.println(classLoader);            // 当前是系统的类加载器
         // 测试JDK内部的类是谁加载的
         classLoader = Class.forName("java.lang.Object").getClassLoader();
         System.out.println(classLoader);            // 根路径下的类加载器
         // 如何获得系统类加载器可以加载的路径
         System.out.println(System.getProperty("java.class.path"));
         /**C:\Program Files\Java\jdk1.8.0_281\jre\lib\charsets.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\deploy.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\access-bridge-64.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\cldrdata.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\dnsns.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\jaccess.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\jfxrt.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\localedata.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\nashorn.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\sunec.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\sunjce_provider.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\sunmscapi.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\sunpkcs11.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\ext\zipfs.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\javaws.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\jce.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\jfr.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\jfxswt.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\jsse.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\management-agent.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\plugin.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\resources.jar;
          * C:\Program Files\Java\jdk1.8.0_281\jre\lib\rt.jar;
          * E:\Project  For Study\Java01\out\production\Java01;
          * D:\Software\For Work\Idea\IntelliJ IDEA2020(64bit)\idea\IntelliJ IDEA 2020.1\lib\idea_rt.jar
          */
     }
 }