/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.net.www.protocol.jar;

import java.io.IOException;

import java.io.FileNotFoundException;

import java.net.URL;

import java.net.URLConnection;

import java.util.HashMap;

import java.util.jar.JarFile;

import java.security.Permission;

import sun.net.util.URLUtil;

/* A factory for cached JAR file. This class is used to both retrieve

 * and cache Jar files.

 *

 * @author Benjamin Renaud

 * @since JDK1.2

 */

class JarFileFactory implements URLJarFile.URLJarFileCloseController {

    /* the url to file cache */

    private static HashMap<String, JarFile> fileCache = new HashMap<String, JarFile>();

    /* the file to url cache */

    private static HashMap<JarFile, URL> urlCache = new HashMap<JarFile, URL>();

    URLConnection getConnection(JarFile jarFile) throws IOException {

        URL u = urlCache.get(jarFile);

        if (u != null)

            return u.openConnection();

        return null;

    }

    public JarFile get(URL url) throws IOException {

        return get(url, true);

    }

    JarFile get(URL url, boolean useCaches) throws IOException {

        if (url.getProtocol().equalsIgnoreCase("file")) {

            // Deal with UNC pathnames specially. See 4180841

            String host = url.getHost();

            if (host != null && !host.equals("") &&

                !host.equalsIgnoreCase("localhost")) {

                url = new URL("file", "", "//" + host + url.getPath());

            }

        }

        JarFile result = null;

        JarFile local_result = null;

        if (useCaches) {

            synchronized (this) {

                result = getCachedJarFile(url);

            }

            if (result == null) {

                local_result = URLJarFile.getJarFile(url, this);

                synchronized (this) {

                    result = getCachedJarFile(url);

                    if (result == null) {

                        fileCache.put(URLUtil.urlNoFragString(url), local_result);

                        urlCache.put(local_result, url);

                        result = local_result;

                    } else {

                        if (local_result != null) {

                            local_result.close();

                        }

                    }

                }

            }

        } else {

            result = URLJarFile.getJarFile(url, this);

        }

        if (result == null)

            throw new FileNotFoundException(url.toString());

        return result;

    }

    /**

     * Callback method of the URLJarFileCloseController to

     * indicate that the JarFile is close. This way we can

     * remove the JarFile from the cache

     */

    public void close(JarFile jarFile) {

        URL urlRemoved = urlCache.remove(jarFile);

        if( urlRemoved != null) {

                fileCache.remove(URLUtil.urlNoFragString(urlRemoved));

        }

    }

    private JarFile getCachedJarFile(URL url) {

        JarFile result = fileCache.get(URLUtil.urlNoFragString(url));

        /* if the JAR file is cached, the permission will always be there */

        if (result != null) {

            Permission perm = getPermission(result);

            if (perm != null) {

                SecurityManager sm = System.getSecurityManager();

                if (sm != null) {

                    try {

                        sm.checkPermission(perm);

                    } catch (SecurityException se) {

                        // fallback to checkRead/checkConnect for pre 1.2

                        // security managers

                        if ((perm instanceof java.io.FilePermission) &&

                            perm.getActions().indexOf("read") != -1) {

                            sm.checkRead(perm.getName());

                        } else if ((perm instanceof

                            java.net.SocketPermission) &&

                            perm.getActions().indexOf("connect") != -1) {

                            sm.checkConnect(url.getHost(), url.getPort());

                        } else {

                            throw se;

                        }

                    }

                }

            }

        }

        return result;

    }

    private Permission getPermission(JarFile jarFile) {

        try {

            if (uc != null)

                return uc.getPermission();

        } catch (IOException ioe) {

            // gulp

        }

        return null;

    }

}