/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited

  *

  * 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.acegisecurity.wrapper;

 import org.acegisecurity.util.PortResolver;

 import org.acegisecurity.util.PortResolverImpl;

 import org.springframework.util.Assert;

 import org.springframework.util.ReflectionUtils;

 import java.io.IOException;

 import java.lang.reflect.Constructor;

 import javax.servlet.Filter;

 import javax.servlet.FilterChain;

 import javax.servlet.FilterConfig;

 import javax.servlet.ServletException;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import javax.servlet.http.HttpServletRequest;

 /**

  * A <code>Filter</code> which populates the <code>ServletRequest</code> with a new request wrapper.<p>Several

  * request wrappers are included with the framework. The simplest version is {@link

  * SecurityContextHolderAwareRequestWrapper}. A more complex and powerful request wrapper is {@link

  * org.acegisecurity.wrapper.SavedRequestAwareWrapper}. The latter is also the default.</p>

  *  <p>To modify the wrapper used, call {@link #setWrapperClass(Class)}.</p>

  *  <p>Any request wrapper configured for instantiation by this class must provide a public constructor that

  * accepts two arguments, being a <code>HttpServletRequest</code> and a <code>PortResolver</code>.</p>

  *

  * @author Orlando Garcia Carmona

  * @author Ben Alex

  * @version $Id: SecurityContextHolderAwareRequestFilter.java 1496 2006-05-23 13:38:33Z benalex $

  */

 public class SecurityContextHolderAwareRequestFilter implements Filter {

     //~ Instance fields ================================================================================================

     private Class wrapperClass = SavedRequestAwareWrapper.class;

     private Constructor constructor;

     private PortResolver portResolver = new PortResolverImpl();

     //~ Methods ========================================================================================================

     public void destroy() {}

     public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)

         throws IOException, ServletException {

         HttpServletRequest request = (HttpServletRequest) servletRequest;

         if (!wrapperClass.isAssignableFrom(request.getClass())) {

             if (constructor == null) {

                 try {

                     constructor = wrapperClass.getConstructor(new Class[] {HttpServletRequest.class, PortResolver.class});

                 } catch (Exception ex) {

                     ReflectionUtils.handleReflectionException(ex);

                 }

             }

             try {

                 request = (HttpServletRequest) constructor.newInstance(new Object[] {request, portResolver});

             } catch (Exception ex) {

                 ReflectionUtils.handleReflectionException(ex);

             }

         }

         filterChain.doFilter(request, servletResponse);

     }

     public void init(FilterConfig filterConfig) throws ServletException {}

     public void setPortResolver(PortResolver portResolver) {

         Assert.notNull(portResolver, "PortResolver required");

         this.portResolver = portResolver;

     }

     public void setWrapperClass(Class wrapperClass) {

         Assert.notNull(wrapperClass, "WrapperClass required");

         Assert.isTrue(HttpServletRequest.class.isAssignableFrom(wrapperClass), "Wrapper must be a HttpServletRequest");

         this.wrapperClass = wrapperClass;

     }

 }