类加载器常用方法

public class ClassLoaderDemo {

    public static void main(String[] args) throws IOException {
        // static getSystemClassLoader()：获取系统类加载器
        ClassLoader systemClassLoader = ClassLoader.getSystemClassLoader();

        // 获取系统类加载器的父类加载器--------》平台类加载器
        ClassLoader platformClassLoader = systemClassLoader.getParent();

        // 获取平台类加载器的父类加载器--------》启动类加载器
        ClassLoader bootstrap = platformClassLoader.getParent();

        System.out.println("系统类加载器" + systemClassLoader);// 系统类加载器sun.misc.Launcher$AppClassLoader@4e0e2f2a
        System.out.println("平台类加载器" + platformClassLoader);// 平台类加载器sun.misc.Launcher$ExtClassLoader@2a139a55
        System.out.println("启动类加载器" + bootstrap);// 启动类加载器null

        // 利用加载器加载指定文件
        InputStream is = systemClassLoader.getResourceAsStream("prop.properties");
        Properties prop = new Properties();
        prop.load(is);
        System.out.println(prop);
        is.close();
    }
}