Metacat

/**

 *  '$RCSfile$'

 *    Purpose: A Class that tracks sessions for MetaCatServlet users.

 *  Copyright: 2000 Regents of the University of California and the

 *             National Center for Ecological Analysis and Synthesis

 *    Authors: Matt Jones

 *    Release: @release@

 *

 *   '$Author$'

 *     '$Date$'

 * '$Revision$'

 */

package edu.ucsb.nceas.metacat;

import java.net.ConnectException;

import javax.servlet.http.HttpSession;

import javax.servlet.http.HttpServletRequest;

/**

 * A Class that implements session tracking for MetaCatServlet users.

 * User's login data are stored in the session object.

 * User authentication is done through a dynamically determined AuthInterface.

 */

public class AuthSession {

  private String authClass = null;

  private HttpSession session = null;

  private AuthInterface authService = null;

  private String statusMessage = null;

  /**

   * Construct an AuthSession

   */

    // Determine our session authentication method and

    // create an instance of the auth class

    MetaCatUtil util = new MetaCatUtil();

    authClass = util.getOption("authclass");

    authService = (AuthInterface)createObject(authClass);

  /**

   * determine if the credentials for this session are valid by

   * authenticating them using the authService configured for this session.

   * @param request the request made from the client

   * @param username the username entered when login

   * @param password the password entered when login

                        String username, String password)  {

    String message = null;

    try {

      if ( authService.authenticate(username, password) ) {

        this.statusMessage = formatOutput("login", message);

        return false;

    } catch ( ConnectException ce ) {

      message = ise.getMessage();

  private HttpSession getSession(HttpServletRequest request,

                            String username, String password)

                                throws IllegalStateException {

    // get the current session object, create one if necessary

    HttpSession session = request.getSession(true);

    // if it is still in use invalidate and get a new one

    if ( !session.isNew() ) {

      session.invalidate();

      session = request.getSession(true);

    }

    // store username & password in the session for later use, especially by

    // the authenticate() method

    session.setMaxInactiveInterval(-1);

    session.setAttribute("username", username);

    session.setAttribute("password", password);

    return session;

  }

   * Get the message associated with authenticating this session. The

   * message is formatted in XML.

   */

  public String getMessage()

  {

    return this.statusMessage;

  }

   * Determine if the session has been successfully authenticated

   * @returns boolean true if authentication was successful, false otherwise

   */

  {

    return this.isAuthenticated;

  }

   * Invalidate this HTTPSession object.

   * All objects stored in the session are unbound.

   */

  {

    this.isAuthenticated = false;

    this.session.setAttribute("isAuthenticated", new Boolean(isAuthenticated));

    this.statusMessage = formatOutput("error", message);

    this.session.setAttribute("statusMessage", this.statusMessage);

    this.session.invalidate();

  }

   * format the output in xml for processing from client applications

   *

   * @param tag the root element tag for the message (error or success)

   * @param message the message content of the root element

   */

  private String formatOutput(String tag, String message) {

    StringBuffer out = new StringBuffer();

    out.append("<?xml version=\"1.0\"?>\n");

    out.append("<" + tag + ">");

    return out.toString();

  }

  /**

   * Instantiate a class using the name of the class at runtime

   *

   * @param className the fully qualified name of the class to instantiate

   */

    try {

      Class classDefinition = Class.forName(className);

      object = classDefinition.newInstance();

    } catch (InstantiationException e) {

    return object;

  }

}