/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.spi;
  
  import java.net.URL;
  import java.net.URLClassLoader;
  
  /**
   * An almost trivial no fuss implementation of a class loader following the
   * child-first delegation model.
   * 
   * @author Ceki Gulcu
   */
  public class LocalFirstClassLoader extends URLClassLoader {
  
      public LocalFirstClassLoader(URL[] urls) {
          super(urls);
      }
  
      public LocalFirstClassLoader(URL[] urls, ClassLoader parent) {
          super(urls, parent);
      }
  
      public void addURL(URL url) {
          super.addURL(url);
      }
  
      public Class<?> loadClass(String name) throws ClassNotFoundException {
          return loadClass(name, false);
      }
  
      /**
       * We override the parent-first behavior established by java.lang.Classloader.
       * 
       * The implementation is surprisingly straightforward.
       */
      protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
  
          // First, check if the class has already been loaded
          Class<?> c = findLoadedClass(name);
  
          // if not loaded, search the local (child) resources
          if (c == null) {
              try {
                  c = findClass(name);
              } catch (ClassNotFoundException cnfe) {
                  // ignore
              }
          }
  
          // if we could not find it, delegate to parent
          // Note that we don't attempt to catch any ClassNotFoundException
          if (c == null) {
              if (getParent() != null) {
                  c = getParent().loadClass(name);
              } else {
                  c = getSystemClassLoader().loadClass(name);
              }
          }
  
          if (resolve) {
              resolveClass(c);
          }
  
          return c;
      }
  }