How to use

ReloadingClassLoader

in

org.apache.wicket.application

/**
 * Instantiate the reloading class loader
 */
public ReloadingWicketFilter()
{
  // Create a reloading classloader
  reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
}

Class<?> clazz = findLoadedClass(name);
  final ClassLoader parent = getParent();
  if (tryClassHere(name))
      clazz = findClass(name);
      watchForModifications(clazz);
  resolveClass(clazz);

/**
 * Gets a resource from this <code>ClassLoader</class>.  If the
 * resource does not exist in this one, we check the parent.
 * Please note that this is the exact opposite of the
 * <code>ClassLoader</code> spec. We use it to work around inconsistent class loaders from third
 * party vendors.
 * 
 * @param name
 *            of resource
 */
@Override
public final URL getResource(final String name)
{
  URL resource = findResource(name);
  ClassLoader parent = getParent();
  if (resource == null && parent != null)
  {
    resource = parent.getResource(name);
  }
  return resource;
}

/**
 * Create a new reloading ClassLoader from a list of URLs, and initialize the
 * ModificationWatcher to detect class file modifications
 * 
 * @param parent
 *            the parent classloader in case the class file cannot be loaded from the above
 *            locations
 */
public ReloadingClassLoader(ClassLoader parent)
{
  super(new URL[] { }, parent);
  // probably doubles from this class, but just in case
  addClassLoaderUrls(parent);
  for (Iterator<URL> iter = urls.iterator(); iter.hasNext();)
  {
    addURL(iter.next());
  }
  watcher = new ModificationWatcher(pollFrequency);
}

  public void onChange()
  {
    // Remove the ModificationWatcher from the current reloading class loader
    reloadingClassLoader.destroy();
    /*
     * Create a new classloader, as there is no way to clear a ClassLoader's cache. This
     * supposes that we don't share objects across application instances, this is almost
     * true, except for Wicket's Session object.
     */
    reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
    try
    {
      init(filterConfig);
    }
    catch (ServletException e)
    {
      throw new RuntimeException(e);
    }
  }
});

throws ServletException
reloadingClassLoader.setListener(new IChangeListener<Class<?>>()
    reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
    try

/**
 * Add all the url locations we can find for the provided class loader
 * 
 * @param loader
 *            class loader
 */
private static void addClassLoaderUrls(ClassLoader loader)
{
  if (loader != null)
  {
    final Enumeration<URL> resources;
    try
    {
      resources = loader.getResources("");
    }
    catch (IOException e)
    {
      throw new RuntimeException(e);
    }
    while (resources.hasMoreElements())
    {
      URL location = resources.nextElement();
      ReloadingClassLoader.addLocation(location);
    }
  }
}

/**
 * Create a new reloading ClassLoader from a list of URLs, and initialize the
 * ModificationWatcher to detect class file modifications
 * 
 * @param parent
 *            the parent classloader in case the class file cannot be loaded from the above
 *            locations
 */
public ReloadingClassLoader(ClassLoader parent)
{
  super(new URL[] {}, parent);
  // probably doubles from this class, but just in case
  addClassLoaderUrls(parent);
  for (Iterator i = urls.iterator(); i.hasNext();)
  {
    addURL((URL)i.next());
  }
  watcher = new ModificationWatcher(pollFrequency);
}

  public void onChange()
  {
    // Remove the ModificationWatcher from the current reloading class loader
    reloadingClassLoader.destroy();
    /*
     * Create a new classloader, as there is no way to clear a ClassLoader's cache. This
     * supposes that we don't share objects across application instances, this is almost
     * true, except for Wicket's Session object.
     */
    reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
    try
    {
      init(filterConfig);
    }
    catch (ServletException e)
    {
      throw new RuntimeException(e);
    }
  }
});

reloadingClassLoader.setListener(new IChangeListener()
    reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
    try

/**
 * Add all the url locations we can find for the provided class loader
 * 
 * @param loader
 *            class loader
 */
private static void addClassLoaderUrls(ClassLoader loader)
{
  if (loader != null)
  {
    final Enumeration<URL> resources;
    try
    {
      resources = loader.getResources("");
    }
    catch (IOException e)
    {
      throw new RuntimeException(e);
    }
    while (resources.hasMoreElements())
    {
      URL location = resources.nextElement();
      ReloadingClassLoader.addLocation(location);
    }
  }
}

Class clazz = findLoadedClass(name);
  final ClassLoader parent = getParent();
  if (tryClassHere(name))
      clazz = findClass(name);
      watchForModifications(clazz);
  resolveClass(clazz);

/**
 * Create a new reloading ClassLoader from a list of URLs, and initialize the
 * ModificationWatcher to detect class file modifications
 * 
 * @param parent
 *            the parent classloader in case the class file cannot be loaded from the above
 *            locations
 */
public ReloadingClassLoader(ClassLoader parent)
{
  super(new URL[] { }, parent);
  // probably doubles from this class, but just in case
  addClassLoaderUrls(parent);
  for (URL url : urls)
  {
    addURL(url);
  }
  Duration pollFrequency = Duration.seconds(3);
  watcher = new ModificationWatcher(pollFrequency);
}

/**
 * Gets a resource from this <code>ClassLoader</class>.  If the
 * resource does not exist in this one, we check the parent.
 * Please note that this is the exact opposite of the
 * <code>ClassLoader</code> spec.  We use it to work around
 * inconsistent class loaders from third party vendors.
 *
 * @param name of resource
 */
public final URL getResource(final String name)
{
  URL resource = findResource(name);
  ClassLoader parent = getParent();
  if (resource == null && parent != null)
  {
    resource = parent.getResource(name);
  }
  return resource;
}

  @Override
  public void onChange(Class<?> clz)
  {
    destroy();
    // Remove the ModificationWatcher from the current reloading class loader
    reloadingClassLoader.destroy();
    /*
     * Create a new classloader, as there is no way to clear a ClassLoader's cache. This
     * supposes that we don't share objects across application instances, this is almost
     * true, except for Wicket's Session object.
     */
    reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
    try
    {
      init(filterConfig);
    }
    catch (ServletException e)
    {
      throw new RuntimeException(e);
    }
  }
});

throws ServletException
reloadingClassLoader.setListener(new IChangeListener<Class<?>>()
    reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
    try

/**
 * Instantiate the reloading class loader
 */
public ReloadingWicketFilter()
{
  // Create a reloading classloader
  reloadingClassLoader = new ReloadingClassLoader(getClass().getClassLoader());
}

/**
 * Add all the url locations we can find for the provided class loader
 * 
 * @param loader
 *            class loader
 */
private static void addClassLoaderUrls(ClassLoader loader)
{
  if (loader != null)
  {
    final Enumeration resources;
    try
    {
      resources = loader.getResources("");
    }
    catch (IOException e)
    {
      throw new RuntimeException(e);
    }
    while (resources.hasMoreElements())
    {
      URL location = (URL)resources.nextElement();
      ReloadingClassLoader.addLocation(location);
    }
  }
}

Class<?> clazz = findLoadedClass(name);
  final ClassLoader parent = getParent();
  if (tryClassHere(name))
      clazz = findClass(name);
      watchForModifications(clazz);
  resolveClass(clazz);

/**
 * Create a new reloading ClassLoader from a list of URLs, and initialize the
 * ModificationWatcher to detect class file modifications
 * 
 * @param parent
 *            the parent classloader in case the class file cannot be loaded from the above
 *            locations
 */
public ReloadingClassLoader(ClassLoader parent)
{
  super(new URL[] { }, parent);
  // probably doubles from this class, but just in case
  addClassLoaderUrls(parent);
  for (URL url : urls)
  {
    addURL(url);
  }
  Duration pollFrequency = Duration.seconds(3);
  watcher = new ModificationWatcher(pollFrequency);
}