/*
 * =============================================================================
 * 
 *   Copyright (c) 2007-2010, The JASYPT team (http://www.jasypt.org)
 * 
 *   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.jasypt.web.pbeconfig;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;


 This filter is intended to avoid access to the web application until
 an admin has set the encryption passwords. It will query the web PBE config
 system to know whether passwords have been set and, if not, it will show the
 user a plain Access Forbidden page. 


 An example web.xml fragment (being applied on a Struts servlet):

   <filter>
       <filter-name>webPBEConfigFilter</filter-name>
       <filter-class>org.jasypt.web.pbeconfig.WebPBEConfigFilter</filter-class>
   </filter>
   <filter-mapping>
       <filter-name>webPBEConfigFilter</filter-name>
       <servlet-name>strutsActionServlet</servlet-name>
   </filter-mapping>    

Author:
Daniel Fernández
Since:
1.3/**
 * <p>
 *  This filter is intended to avoid access to the web application until
 *  an admin has set the encryption passwords. It will query the web PBE config
 *  system to know whether passwords have been set and, if not, it will show the
 *  user a plain <i>Access Forbidden</i> page. 
 * </p>
 * <p>
 *  An example <tt>web.xml</tt> fragment (being applied on a Struts servlet):
 * </p>
 * <pre>
 *    &lt;filter>
 *        &lt;filter-name>webPBEConfigFilter&lt;/filter-name>
 *        &lt;filter-class>org.jasypt.web.pbeconfig.WebPBEConfigFilter&lt;/filter-class>
 *    &lt;/filter>
 *
 *    &lt;filter-mapping>
 *        &lt;filter-name>webPBEConfigFilter&lt;/filter-name>
 *        &lt;servlet-name>strutsActionServlet&lt;/servlet-name>
 *    &lt;/filter-mapping>    
 * </pre>
 * 
 * @since 1.3
 * 
 * @author Daniel Fern&aacute;ndez
 *
 */
public final class WebPBEConfigFilter implements Filter {

    
    public void doFilter(final ServletRequest request, final ServletResponse response,
            final FilterChain chain) throws IOException, ServletException {

        final WebPBEConfigRegistry registry = WebPBEConfigRegistry.getInstance();
        if (registry.isWebConfigurationDone()) {
            // If it is initialized, quickly continue filter chain
            chain.doFilter(request, response);
        } else {
            // Not initialized, a Forbidden page must be shown, chain broken
            PrintWriter printWriter = response.getWriter();
            printWriter.write(WebPBEConfigHtmlUtils.createNotInitializedHtml());
            printWriter.flush();
        }
        
    }

    
    public void init(final FilterConfig filterConfig) throws ServletException {
        // Nothing to be done here.
    }

    public void destroy() {
        // Nothing to be done here.
    }


    
    
}