/* * $Id: MemoryUserDatabase.java 54929 2004-10-16 16:38:42Z germuska $  * * Copyright 2000-2004 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.struts.examples.mailreader.memory;import java.io.BufferedInputStream;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStreamWriter;import java.io.PrintWriter;import java.util.HashMap;import org.apache.commons.digester.Digester;import org.apache.commons.digester.ObjectCreationFactory;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.apache.struts.examples.mailreader.Subscription;import org.apache.struts.examples.mailreader.User;import org.apache.struts.examples.mailreader.UserDatabase;import org.apache.struts.examples.mailreader.ExpiredPasswordException;import org.xml.sax.Attributes;/** * <p>Concrete implementation of {@link UserDatabase} for an in-memory * database backed by an XML data file.</p> * * @version $Rev: 54929 $ $Date: 2004-10-16 09:38:42 -0700 (Sat, 16 Oct 2004) $ * @since Struts 1.1 */public class MemoryUserDatabase implements UserDatabase {    // ----------------------------------------------------------- Constructors    // ----------------------------------------------------- Instance Variables    /**     * Logging output for this user database instance.     */    private Log log = LogFactory.getLog(this.getClass());    /**     * The {@link User}s associated with this UserDatabase, keyed by username.     */    private HashMap users = new HashMap();    // ------------------------------------------------------------- Properties    /**     * Absolute pathname to the persistent file we use for loading and storing     * persistent data.     */    private String pathname = null;    private String pathnameOld = null;    private String pathnameNew = null;    public String getPathname() {        return (this.pathname);    }    public void setPathname(String pathname) {        this.pathname = pathname;        pathnameOld = pathname + ".old";        pathnameNew = pathname + ".new";    }    // --------------------------------------------------------- Public Methods    // See interface for Javadoc    public void close() throws Exception {        save();    }    // See interface for Javadoc    public User createUser(String username) {        synchronized (users) {            if (users.get(username) != null) {                throw new IllegalArgumentException("Duplicate user '" +                                                   username + "'");            }            if (log.isTraceEnabled()) {                log.trace("Creating user '" + username + "'");            }            MemoryUser user = new MemoryUser(this, username);            synchronized (users) {                users.put(username, user);            }            return (user);        }    }    // See interface for Javadoc    public User findUser(String username) throws ExpiredPasswordException {        synchronized (users) {            return ((User) users.get(username));        }    }    // See interface for Javadoc    public User[] findUsers() {        synchronized (users) {            User results[] = new User[users.size()];            return ((User[]) users.values().toArray(results));        }    }    // See interface for Javadoc    public void open() throws Exception {        FileInputStream fis = null;        BufferedInputStream bis = null;        try {            // Acquire an input stream to our database file            if (log.isDebugEnabled()) {                log.debug("Loading database from '" + pathname + "'");            }            fis = new FileInputStream(pathname);            bis = new BufferedInputStream(fis);            // Construct a digester to use for parsing            Digester digester = new Digester();            digester.push(this);            digester.setValidating(false);            digester.addFactoryCreate                ("database/user",                 new MemoryUserCreationFactory(this));            digester.addFactoryCreate                ("database/user/subscription",                 new MemorySubscriptionCreationFactory());            // Parse the input stream to initialize our database            digester.parse(bis);            bis.close();            bis = null;            fis = null;        } catch (Exception e) {            log.error("Loading database from '" + pathname + "':", e);            throw e;        } finally {            if (bis != null) {                try {                    bis.close();                } catch (Throwable t) {                    ;                }                bis = null;                fis = null;            }        }    }    // See interface for Javadoc    public void removeUser(User user) {        if (!(this == user.getDatabase())) {            throw new IllegalArgumentException                ("User not associated with this database");        }        if (log.isTraceEnabled()) {            log.trace("Removing user '" + user.getUsername() + "'");        }        synchronized (users) {            users.remove(user.getUsername());        }    }    // See interface for Javadoc    public void save() throws Exception {        if (log.isDebugEnabled()) {            log.debug("Saving database to '" + pathname + "'");        }        File fileNew = new File(pathnameNew);        PrintWriter writer = null;        try {            // Configure our PrintWriter            FileOutputStream fos = new FileOutputStream(fileNew);            OutputStreamWriter osw = new OutputStreamWriter(fos);            writer = new PrintWriter(osw);            // Print the file prolog            writer.println("<?xml version='1.0'?>");            writer.println("<database>");            // Print entries for each defined user and associated subscriptions            User users[] = findUsers();            for (int i = 0; i < users.length; i++) {                writer.print("  ");                writer.println(users[i]);                Subscription subscriptions[] =                    users[i].getSubscriptions();                for (int j = 0; j < subscriptions.length; j++) {                    writer.print("    ");                    writer.println(subscriptions[j]);                    writer.print("    ");                    writer.println("</subscription>");                }                writer.print("  ");                writer.println("</user>");            }            // Print the file epilog            writer.println("</database>");            // Check for errors that occurred while printing            if (writer.checkError()) {                writer.close();                fileNew.delete();                throw new IOException                    ("Saving database to '" + pathname + "'");            }            writer.close();            writer = null;        } catch (IOException e) {            if (writer != null) {                writer.close();            }            fileNew.delete();            throw e;        }        // Perform the required renames to permanently save this file        File fileOrig = new File(pathname);        File fileOld = new File(pathnameOld);        if (fileOrig.exists()) {            fileOld.delete();            if (!fileOrig.renameTo(fileOld)) {                throw new IOException                    ("Renaming '" + pathname + "' to '" + pathnameOld + "'");            }        }        if (!fileNew.renameTo(fileOrig)) {            if (fileOld.exists()) {                fileOld.renameTo(fileOrig);            }            throw new IOException                ("Renaming '" + pathnameNew + "' to '" + pathname + "'");        }        fileOld.delete();    }}/** * Digester object creation factory for subscription instances. */class MemorySubscriptionCreationFactory implements ObjectCreationFactory {    private Digester digester = null;    public Digester getDigester() {        return (this.digester);    }    public void setDigester(Digester digester) {        this.digester = digester;    }    public Object createObject(Attributes attributes) {        String host = attributes.getValue("host");        User user = (User) digester.peek();        Subscription subscription = user.createSubscription(host);        String autoConnect = attributes.getValue("autoConnect");        if (autoConnect == null) {            autoConnect = "false";        }        if ("true".equalsIgnoreCase(autoConnect) ||            "yes".equalsIgnoreCase(autoConnect)) {            subscription.setAutoConnect(true);        } else {            subscription.setAutoConnect(false);        }        subscription.setPassword(attributes.getValue("password"));        subscription.setType(attributes.getValue("type"));        subscription.setUsername(attributes.getValue("username"));        return (subscription);    }}/** * Digester object creation factory for user instances. */class MemoryUserCreationFactory implements ObjectCreationFactory {    public MemoryUserCreationFactory(MemoryUserDatabase database) {        this.database = database;    }    private MemoryUserDatabase database = null;    private Digester digester = null;    public Digester getDigester() {        return (this.digester);    }    public void setDigester(Digester digester) {        this.digester = digester;    }    public Object createObject(Attributes attributes) {        String username = attributes.getValue("username");        User user = database.createUser(username);        user.setFromAddress(attributes.getValue("fromAddress"));        user.setFullName(attributes.getValue("fullName"));        user.setPassword(attributes.getValue("password"));        user.setReplyToAddress(attributes.getValue("replyToAddress"));        return (user);    }}