import java.lang.reflect.Field;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.List;

public class JvmClassLoaderPrintPath {

 public static void main(String[] args) {

 // 启动类加载器
 URL[] urls = sun.misc.Launcher.getBootstrapClassPath().getURLs();
 System.out.println("启动类加载器");
 for (URL url : urls) {
 System.out.println(" ===> " + url.toExternalForm());
 }

 // 扩展类加载器
 printClassloader("扩展类加载器",JvmClassLoaderPrintPath.class.getClassLoader().getParent());

 // 应用类加载器
 printClassloader("应用类加载器",JvmClassLoaderPrintPath.class.getClassLoader());

 }

 private static void printClassloader(String name, ClassLoader classLoader) {
 System.out.println();
 if (null != classLoader) {
 System.out.println(name + " Classloader -> " + classLoader.toString());
 printURLForClassloader(classLoader);
 } else {
 System.out.println(name + " Classloader -> null");
 }
 }

 private static void printURLForClassloader(ClassLoader classLoader) {
 Object ucp = insightField(classLoader,"ucp");
 Object path = insightField(ucp,"path");
 List paths = (List) path;
 for (Object p : paths) {
 System.out.println(" ===> " + p.toString());
 }
 }

 private static Object insightField(Object obj, String fName) {
 Field f = null;
 try {
 if (obj instanceof URLClassLoader) {
 f = URLClassLoader.class.getDeclaredField(fName);
 } else {
 f = obj.getClass().getDeclaredField(fName);
 }
 f.setAccessible(true);
 return f.get(obj);
 }
 catch (Exception ex) {
 ex.printStackTrace();
 }
 return null;
 }


}