| /* |
| * Copyright 1999,2004 The Apache Software Foundation. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| |
| package org.apache.catalina; |
| |
| |
| import java.beans.PropertyChangeListener; |
| |
| |
| /** |
| * A <b>Loader</b> represents a Java ClassLoader implementation that can |
| * be used by a Container to load class files (within a repository associated |
| * with the Loader) that are designed to be reloaded upon request, as well as |
| * a mechanism to detect whether changes have occurred in the underlying |
| * repository. |
| * <p> |
| * In order for a <code>Loader</code> implementation to successfully operate |
| * with a <code>Context</code> implementation that implements reloading, it |
| * must obey the following constraints: |
| * <ul> |
| * <li>Must implement <code>Lifecycle</code> so that the Context can indicate |
| * that a new class loader is required. |
| * <li>The <code>start()</code> method must unconditionally create a new |
| * <code>ClassLoader</code> implementation. |
| * <li>The <code>stop()</code> method must throw away its reference to the |
| * <code>ClassLoader</code> previously utilized, so that the class loader, |
| * all classes loaded by it, and all objects of those classes, can be |
| * garbage collected. |
| * <li>Must allow a call to <code>stop()</code> to be followed by a call to |
| * <code>start()</code> on the same <code>Loader</code> instance. |
| * <li>Based on a policy chosen by the implementation, must call the |
| * <code>Context.reload()</code> method on the owning <code>Context</code> |
| * when a change to one or more of the class files loaded by this class |
| * loader is detected. |
| * </ul> |
| * |
| * @author Craig R. McClanahan |
| * @version $Revision$ $Date$ |
| */ |
| |
| public interface Loader { |
| |
| |
| // ------------------------------------------------------------- Properties |
| |
| |
| /** |
| * Return the Java class loader to be used by this Container. |
| */ |
| public ClassLoader getClassLoader(); |
| |
| |
| /** |
| * Return the Container with which this Loader has been associated. |
| */ |
| public Container getContainer(); |
| |
| |
| /** |
| * Set the Container with which this Loader has been associated. |
| * |
| * @param container The associated Container |
| */ |
| public void setContainer(Container container); |
| |
| |
| /** |
| * Return the "follow standard delegation model" flag used to configure |
| * our ClassLoader. |
| */ |
| public boolean getDelegate(); |
| |
| |
| /** |
| * Set the "follow standard delegation model" flag used to configure |
| * our ClassLoader. |
| * |
| * @param delegate The new flag |
| */ |
| public void setDelegate(boolean delegate); |
| |
| |
| /** |
| * Return descriptive information about this Loader implementation and |
| * the corresponding version number, in the format |
| * <code><description>/<version></code>. |
| */ |
| public String getInfo(); |
| |
| |
| /** |
| * Return the reloadable flag for this Loader. |
| */ |
| public boolean getReloadable(); |
| |
| |
| /** |
| * Set the reloadable flag for this Loader. |
| * |
| * @param reloadable The new reloadable flag |
| */ |
| public void setReloadable(boolean reloadable); |
| |
| |
| // --------------------------------------------------------- Public Methods |
| |
| |
| /** |
| * Add a property change listener to this component. |
| * |
| * @param listener The listener to add |
| */ |
| public void addPropertyChangeListener(PropertyChangeListener listener); |
| |
| |
| /** |
| * Add a new repository to the set of repositories for this class loader. |
| * |
| * @param repository Repository to be added |
| */ |
| public void addRepository(String repository); |
| |
| |
| /** |
| * Return the set of repositories defined for this class loader. |
| * If none are defined, a zero-length array is returned. |
| */ |
| public String[] findRepositories(); |
| |
| |
| /** |
| * Has the internal repository associated with this Loader been modified, |
| * such that the loaded classes should be reloaded? |
| */ |
| public boolean modified(); |
| |
| |
| /** |
| * Remove a property change listener from this component. |
| * |
| * @param listener The listener to remove |
| */ |
| public void removePropertyChangeListener(PropertyChangeListener listener); |
| |
| |
| } |