Tomcat example source code file (FileStore.java)

This example Tomcat source code file (FileStore.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

arraylist, bufferedinputstream, container, context, context, file, file, file_ext, io, ioexception, ioexception, objectoutputstream, servlet, standardsession, string, string, util

The Tomcat FileStore.java source code

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.session;


import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;

import javax.servlet.ServletContext;

import org.apache.catalina.Container;
import org.apache.catalina.Context;
import org.apache.catalina.Globals;
import org.apache.catalina.Loader;
import org.apache.catalina.Session;
import org.apache.catalina.Store;
import org.apache.catalina.util.CustomObjectInputStream;


/**
 * Concrete implementation of the <b>Store interface that utilizes
 * a file per saved Session in a configured directory.  Sessions that are
 * saved are still subject to being expired based on inactivity.
 *
 * @author Craig R. McClanahan
 * @version $Revision: 467222 $ $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
 */

public final class FileStore
    extends StoreBase implements Store {


    // ----------------------------------------------------- Constants


    /**
     * The extension to use for serialized session filenames.
     */
    private static final String FILE_EXT = ".session";


    // ----------------------------------------------------- Instance Variables


    /**
     * The pathname of the directory in which Sessions are stored.
     * This may be an absolute pathname, or a relative path that is
     * resolved against the temporary work directory for this application.
     */
    private String directory = ".";


    /**
     * A File representing the directory in which Sessions are stored.
     */
    private File directoryFile = null;


    /**
     * The descriptive information about this implementation.
     */
    private static final String info = "FileStore/1.0";

    /**
     * Name to register for this Store, used for logging.
     */
    private static final String storeName = "fileStore";

    /**
     * Name to register for the background thread.
     */
    private static final String threadName = "FileStore";


    // ------------------------------------------------------------- Properties


    /**
     * Return the directory path for this Store.
     */
    public String getDirectory() {

        return (directory);

    }


    /**
     * Set the directory path for this Store.
     *
     * @param path The new directory path
     */
    public void setDirectory(String path) {

        String oldDirectory = this.directory;
        this.directory = path;
        this.directoryFile = null;
        support.firePropertyChange("directory", oldDirectory,
                                   this.directory);

    }


    /**
     * Return descriptive information about this Store implementation and
     * the corresponding version number, in the format
     * <code><description>/<version>.
     */
    public String getInfo() {

        return (info);

    }

    /**
     * Return the thread name for this Store.
     */
    public String getThreadName() {
        return(threadName);
    }

    /**
     * Return the name for this Store, used for logging.
     */
    public String getStoreName() {
        return(storeName);
    }


    /**
     * Return the number of Sessions present in this Store.
     *
     * @exception IOException if an input/output error occurs
     */
    public int getSize() throws IOException {

        // Acquire the list of files in our storage directory
        File file = directory();
        if (file == null) {
            return (0);
        }
        String files[] = file.list();

        // Figure out which files are sessions
        int keycount = 0;
        for (int i = 0; i < files.length; i++) {
            if (files[i].endsWith(FILE_EXT)) {
                keycount++;
            }
        }
        return (keycount);

    }


    // --------------------------------------------------------- Public Methods


    /**
     * Remove all of the Sessions in this Store.
     *
     * @exception IOException if an input/output error occurs
     */
    public void clear()
        throws IOException {

        String[] keys = keys();
        for (int i = 0; i < keys.length; i++) {
            remove(keys[i]);
        }

    }


    /**
     * Return an array containing the session identifiers of all Sessions
     * currently saved in this Store.  If there are no such Sessions, a
     * zero-length array is returned.
     *
     * @exception IOException if an input/output error occurred
     */
    public String[] keys() throws IOException {

        // Acquire the list of files in our storage directory
        File file = directory();
        if (file == null) {
            return (new String[0]);
        }

        String files[] = file.list();
        
        // Bugzilla 32130
        if((files == null) || (files.length < 1)) {
            return (new String[0]);
        }

        // Build and return the list of session identifiers
        ArrayList list = new ArrayList();
        int n = FILE_EXT.length();
        for (int i = 0; i < files.length; i++) {
            if (files[i].endsWith(FILE_EXT)) {
                list.add(files[i].substring(0, files[i].length() - n));
            }
        }
        return ((String[]) list.toArray(new String[list.size()]));

    }


    /**
     * Load and return the Session associated with the specified session
     * identifier from this Store, without removing it.  If there is no
     * such stored Session, return <code>null.
     *
     * @param id Session identifier of the session to load
     *
     * @exception ClassNotFoundException if a deserialization error occurs
     * @exception IOException if an input/output error occurs
     */
    public Session load(String id)
        throws ClassNotFoundException, IOException {

        // Open an input stream to the specified pathname, if any
        File file = file(id);
        if (file == null) {
            return (null);
        }

        if (! file.exists()) {
            return (null);
        }
        if (manager.getContainer().getLogger().isDebugEnabled()) {
            manager.getContainer().getLogger().debug(sm.getString(getStoreName()+".loading",
                             id, file.getAbsolutePath()));
        }

        FileInputStream fis = null;
        ObjectInputStream ois = null;
        Loader loader = null;
        ClassLoader classLoader = null;
        try {
            fis = new FileInputStream(file.getAbsolutePath());
            BufferedInputStream bis = new BufferedInputStream(fis);
            Container container = manager.getContainer();
            if (container != null)
                loader = container.getLoader();
            if (loader != null)
                classLoader = loader.getClassLoader();
            if (classLoader != null)
                ois = new CustomObjectInputStream(bis, classLoader);
            else
                ois = new ObjectInputStream(bis);
        } catch (FileNotFoundException e) {
            if (manager.getContainer().getLogger().isDebugEnabled())
                manager.getContainer().getLogger().debug("No persisted data file found");
            return (null);
        } catch (IOException e) {
            if (ois != null) {
                try {
                    ois.close();
                } catch (IOException f) {
                    ;
                }
                ois = null;
            }
            throw e;
        }

        try {
            StandardSession session =
                (StandardSession) manager.createEmptySession();
            session.readObjectData(ois);
            session.setManager(manager);
            return (session);
        } finally {
            // Close the input stream
            if (ois != null) {
                try {
                    ois.close();
                } catch (IOException f) {
                    ;
                }
            }
        }
    }


    /**
     * Remove the Session with the specified session identifier from
     * this Store, if present.  If no such Session is present, this method
     * takes no action.
     *
     * @param id Session identifier of the Session to be removed
     *
     * @exception IOException if an input/output error occurs
     */
    public void remove(String id) throws IOException {

        File file = file(id);
        if (file == null) {
            return;
        }
        if (manager.getContainer().getLogger().isDebugEnabled()) {
            manager.getContainer().getLogger().debug(sm.getString(getStoreName()+".removing",
                             id, file.getAbsolutePath()));
        }
        file.delete();

    }


    /**
     * Save the specified Session into this Store.  Any previously saved
     * information for the associated session identifier is replaced.
     *
     * @param session Session to be saved
     *
     * @exception IOException if an input/output error occurs
     */
    public void save(Session session) throws IOException {

        // Open an output stream to the specified pathname, if any
        File file = file(session.getIdInternal());
        if (file == null) {
            return;
        }
        if (manager.getContainer().getLogger().isDebugEnabled()) {
            manager.getContainer().getLogger().debug(sm.getString(getStoreName()+".saving",
                             session.getIdInternal(), file.getAbsolutePath()));
        }
        FileOutputStream fos = null;
        ObjectOutputStream oos = null;
        try {
            fos = new FileOutputStream(file.getAbsolutePath());
            oos = new ObjectOutputStream(new BufferedOutputStream(fos));
        } catch (IOException e) {
            if (oos != null) {
                try {
                    oos.close();
                } catch (IOException f) {
                    ;
                }
            }
            throw e;
        }

        try {
            ((StandardSession)session).writeObjectData(oos);
        } finally {
            oos.close();
        }

    }


    // -------------------------------------------------------- Private Methods


    /**
     * Return a File object representing the pathname to our
     * session persistence directory, if any.  The directory will be
     * created if it does not already exist.
     */
    private File directory() {

        if (this.directory == null) {
            return (null);
        }
        if (this.directoryFile != null) {
            // NOTE:  Race condition is harmless, so do not synchronize
            return (this.directoryFile);
        }
        File file = new File(this.directory);
        if (!file.isAbsolute()) {
            Container container = manager.getContainer();
            if (container instanceof Context) {
                ServletContext servletContext =
                    ((Context) container).getServletContext();
                File work = (File)
                    servletContext.getAttribute(Globals.WORK_DIR_ATTR);
                file = new File(work, this.directory);
            } else {
                throw new IllegalArgumentException
                    ("Parent Container is not a Context");
            }
        }
        if (!file.exists() || !file.isDirectory()) {
            file.delete();
            file.mkdirs();
        }
        this.directoryFile = file;
        return (file);

    }


    /**
     * Return a File object representing the pathname to our
     * session persistence file, if any.
     *
     * @param id The ID of the Session to be retrieved. This is
     *    used in the file naming.
     */
    private File file(String id) {

        if (this.directory == null) {
            return (null);
        }
        String filename = id + FILE_EXT;
        File file = new File(directory(), filename);
        return (file);

    }


}