signonfilter.java

我在加拿大学习的一个比较复杂的在线银行程序.

package com.ebusiness.ebank.security;

/**
 * <p>Title: </p>
 * <p>Description: This class manage user's front-end sign on process. If a user
 *                  has not authenticated and try to access to the web resoures(jsp and actions)
 *                  , the user will be redirected to a loggedout pag on which there is a
 *                  link to allow the user to login. Once the user is
 *                  authenticated, the user can access eBank system based on it's
 *                  role-based security policy. Logout will release the session</p>
 * <p>Copyright: Copyright (c) 2005</p>
 * <p>Company: eBusiness Inc., All right reserved</p>
 * @author unascribed
 * @version 1.0
 */

import java.io.IOException;
import java.util.Properties;
import java.util.Iterator;
import java.util.Enumeration;
import java.util.Set;
import java.util.Map;
import java.util.HashSet;
import java.util.HashMap;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.http.HttpSession;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.apache.log4j.MDC;

import com.ebusiness.ebank.util.Constants;
import com.ebusiness.ebank.exception.SystemException;

import weblogic.servlet.security.ServletAuthentication;
import com.ebusiness.ebank.bean.*;
import java.util.Date;
import java.util.Locale;
import java.sql.Timestamp;

public class SignOnFilter implements Filter
{
    private Logger log = Logger.getLogger(this.getClass());

    private FilterConfig config = null;
    private String errorLoginPage = null;
    private String loginPage = null;
    private String welcomePage = null;
    private String host = null;
    private String loggedoutPage = null;
    private String alreadyLoggedinPage = null;

    public void init(FilterConfig config) throws ServletException
    {
        this.config = config;
        errorLoginPage = config.getInitParameter("errorLogin-page");
        loginPage = config.getInitParameter("login-page");
        welcomePage = config.getInitParameter("welcome-page");
        loggedoutPage = config.getInitParameter("loggedout-page");
        alreadyLoggedinPage = config.getInitParameter("alreadyLoggedin-Page");
        securityConfig();

        log.info("eBank SignOnFilter was initialized");
    }

    public void doFilter(ServletRequest request, ServletResponse  response, FilterChain chain)
        throws IOException, ServletException
    {
        HttpServletRequest hreq = (HttpServletRequest)request;
        String targetURL = hreq.getServletPath();
        log.info("TargetURL: " + targetURL);
        /**
        if ("/jsp/signon/login.jsp".equals(targetURL))
        {
           chain.doFilter(request,response);
           return;
        }
   */
        String userID = (String)hreq.getRemoteUser();

        log.debug("TargetURL: " + targetURL);

        if (host == null)
        {
            String st = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort();
            log.info("URL: " + st);
            host = st;
        }

        if (userID != null) //The user is logged in, so allow the user through
        {
            if ("/login.do".equals(targetURL))
            {
                request.getRequestDispatcher(alreadyLoggedinPage).forward(request, response);
                return;
            }
            else if ("/logout.do".equals(targetURL))
            {
                HttpSession session = hreq.getSession();
                session.invalidate();
                request.getRequestDispatcher(loginPage).forward(request, response);
                return;
            }
            chain.doFilter(request,response);
        }
        else if ("/login.do".equals(targetURL))
            chain.doFilter(request,response);
        else //The user's session was timeout or the user hasn't been logged-in yet
            request.getRequestDispatcher(loggedoutPage).forward(request, response);

        return;
    }

    public void destroy()
    {
        //do nothing
    }

    //load securityConfig properties and initialize FunctionConstraint and ColumnConstraint
    private void securityConfig()
    {
        //load securityConfig properties and initialize FunctionConstraint and ColumnConstraint
        Properties prop = new Properties();
        try
        {
            prop.load(this.getClass().getResourceAsStream("securityConfig.properties"));
        }
        catch (Exception e)
        {
            log.fatal("securityConfig.properties file does not found", e);
        }
        Enumeration props = prop.propertyNames();
        String key = "";
        Set roles = new HashSet();
        Map funcPolicies    = new HashMap();
        Map funcIndicators  = new HashMap();
        Map colPolicies     = new HashMap();
        Map colIndicators   = new HashMap();
        while(props.hasMoreElements())
        {
            key = (String)props.nextElement();

            if (key.indexOf("restricted") > 0 || key.indexOf("authorized") > 0)
            {
                String roleNameKey = key.substring(0, key.indexOf('.'));
                String roleName = prop.getProperty(roleNameKey);
                roles.add(roleName);
                if (key.indexOf("function") > 0) //function restrictions
                {
                    Set functions = (Set)funcPolicies.get(roleName);
                    if (functions == null)
                        functions = new HashSet();
                    functions.add(prop.getProperty(key));
                    funcPolicies.put(roleName, functions);
                    if (key.indexOf("restricted") > 0)
                        funcIndicators.put(roleName, "restricted");
                    else if (key.indexOf("authorized") > 0)
                        funcIndicators.put(roleName, "authorized");
                }
                else if (key.indexOf("column") > 0) //column restrictions
                {
                    Set columns = (Set)colPolicies.get(roleName);
                    if (columns == null)
                        columns = new HashSet();
                    columns.add(prop.getProperty(key));
                    colPolicies.put(roleName, columns);
                    if (key.indexOf("restricted") > 0)
                        colIndicators.put(roleName, "restricted");
                    else if (key.indexOf("authorized") > 0)
                        colIndicators.put(roleName, "authorized");
                }
            }
        }
        log.info("securityConfig properties file was successfully loaded.");

        //Initialize eBank roles and refresh interval for UserContainer
        UserContainer.initEbankRoles((String[])roles.toArray(new String[roles.size()]));
        String refreshInterval = prop.getProperty("refreshInterval");
        if (refreshInterval != null)
        {
            long interval = Long.parseLong(refreshInterval);
            if (interval > 0)
                UserContainer.initRefreshInterval(interval);
        }

        //Initialize FunctionConstraint
        FunctionConstraint.init(funcPolicies, funcIndicators);

        //Initialize ColumnConstraint
        ColumnConstraint.init(colPolicies, colIndicators);

        Iterator i = roles.iterator();
        log.info("There are following roles defined in eBank application: ");
        while (i.hasNext())
        {
            log.info((String)i.next());
        }

        i = funcPolicies.keySet().iterator();
        log.info("******Function Restrictions****** ");
        while (i.hasNext())
        {
            key = (String)i.next();
            log.info("Restricted Functions for Role " + key + ": ");
            Set functions = (Set)funcPolicies.get(key);
            Iterator iter = functions.iterator();
            while (iter.hasNext())
            {
                log.info((String)iter.next());
            }
        }

        i = colPolicies.keySet().iterator();
        log.info("******Column Restrictions****** ");
        while (i.hasNext())
        {
            key = (String)i.next();
            log.info("Restricted Columns for Role " + key + ": ");
            Set columns = (Set)colPolicies.get(key);
            Iterator iter = columns.iterator();
            while (iter.hasNext())
            {
                log.info((String)iter.next());
            }
        }
    }
}