/* * ModuleLoader - A generic, policy-driven class loader. * Copyright (c) 2004, Richard S. Hall * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * *   * Redistributions of source code must retain the above copyright *     notice, this list of conditions and the following disclaimer. *   * Redistributions in binary form must reproduce the above copyright *     notice, this list of conditions and the following disclaimer in *     the documentation and/or other materials provided with the *     distribution. *   * Neither the name of the ungoverned.org nor the names of its *     contributors may be used to endorse or promote products derived *     from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * Contact: Richard S. Hall (heavy@ungoverned.org) * Contributor(s): ***/package org.ungoverned.moduleloader;import java.net.URL;/** * <p> * This class implements a simple <tt>URLPolicy</tt> that the <tt>ModuleManager</tt> * uses if the application does not specify one. This implementation always returns * <tt>null</tt> for <tt>CodeSource</tt> <tt>URL</tt>s, which means that security * is simply ignored. For resource <tt>URL</tt>s, it returns an <tt>URL</tt> in the * form of: * </p> * <pre> *     module://&lt;module-id&gt;/&lt;resource-path&gt; * </pre> * <p> * In order to properly handle the "<tt>module:</tt>" protocol, this policy * also defines a custom <tt>java.net.URLStreamHandler</tt> that it assigns * to each <tt>URL</tt> as it is created. This custom handler is used to * return a custom <tt>java.net.URLConnection</tt> that will correctly parse * the above <tt>URL</tt> and retrieve the associated resource bytes using * methods from <tt>ModuleManager</tt> and <tt>Module</tt>. * </p> * @see org.ungoverned.moduleloader.ModuleManager * @see org.ungoverned.moduleloader.Module * @see org.ungoverned.moduleloader.URLPolicy**/public class DefaultURLPolicy implements URLPolicy{    private ModuleURLStreamHandler m_handler = null;    /**     * <p>     * This method is a stub and always returns <tt>null</tt>.     * </p>     * @param mgr the <tt>ModuleManager</tt> of the module.     * @param module the module for which the <tt>URL</tt> is to be created.     * @return <tt>null</tt>.    **/    public URL createCodeSourceURL(ModuleManager mgr, Module module)    {        return null;    }    /**     * <p>     * This method returns a <tt>URL</tt> that is suitable     * for accessing the bytes of the specified resource.     * </p>     * @param mgr the <tt>ModuleManager</tt> of the module.     * @param module the module for which the resource is being loaded.     * @param rsIdx the index of the <tt>ResourceSource</tt> containing the resource.     * @param name the name of the resource being loaded.     * @return an <tt>URL</tt> for retrieving the resource.    **/    public URL createResourceURL(ModuleManager mgr, Module module, int rsIdx, String name)    {        if (m_handler == null)        {            m_handler = new ModuleURLStreamHandler(mgr);        }        // Add a slash if there is one already, otherwise        // the is no slash separating the host from the file        // in the resulting URL.        if (!name.startsWith("/"))        {            name = "/" + name;        }        try        {            return new URL("module", module.getId(), -1, "/" + rsIdx + name, m_handler);        }        catch (Exception ex)        {            System.err.println("DefaultResourceURLPolicy: " + ex);            return null;        }    }}