com.github.tomakehurst.wiremock.servlet.TrailingSlashFilter Maven / Gradle / Ivy

/*
 * Copyright (C) 2011 Thomas Akehurst
 *
 * 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 com.github.tomakehurst.wiremock.servlet;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.*;

public class TrailingSlashFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
            ServletException {
        
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        String path = getRequestPathFrom(httpServletRequest);
        
        StatusAndRedirectExposingHttpServletResponse wrappedResponse =
            new StatusAndRedirectExposingHttpServletResponse((HttpServletResponse) response, path, httpServletRequest);
        chain.doFilter(request, wrappedResponse);
    }
    
    private static class StatusAndRedirectExposingHttpServletResponse extends HttpServletResponseWrapper {
        
        private String path;
        private HttpServletRequest request;
        
        public StatusAndRedirectExposingHttpServletResponse(HttpServletResponse response, String path, HttpServletRequest request) {
            super(response);
            this.path = path;
            this.request = request;
        }
        
        @Override
        public void sendRedirect(String location) throws IOException {
            if (location.contains(path)) {
                RequestDispatcher dispatcher = request.getRequestDispatcher(getPathPartFromLocation(location));
                try {
                    dispatcher.forward(request, this);
                } catch (ServletException se) {
                    throw new IOException(se);
                }
            }
        }
        
        private String getPathPartFromLocation(String location) throws IOException {
            URL url = new URL(location);
            return url.getPath();
        }
    }
    
    private String getRequestPathFrom(HttpServletRequest httpServletRequest) throws ServletException {
        try {
            String fullPath = new URI(URLEncoder.encode(httpServletRequest.getRequestURI(), "utf-8")).getPath();
            String pathWithoutContext = fullPath.substring(httpServletRequest.getContextPath().length());
            return URLDecoder.decode(pathWithoutContext, "utf-8");
        } catch (URISyntaxException e) {
            throw new ServletException(e);
        } catch (UnsupportedEncodingException e) {
            throw new ServletException(e);
        }
    }
    
    @Override
    public void destroy() {
    }

}