1 /** 2 * Copyright (C) 2012 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.inject.servlet; 18 19 import javax.servlet.http.HttpServletRequest; 20 21 /** 22 * Some servlet utility methods. 23 * 24 * @author ntang (at) google.com (Michael Tang) 25 */ 26 final class ServletUtils { 27 private ServletUtils() { 28 // private to prevent instantiation. 29 } 30 31 /** 32 * Gets the context path relative path of the URI. Returns the path of the 33 * resource relative to the context path for a request's URI, or null if no 34 * path can be extracted. 35 */ 36 // @Nullable 37 public static String getContextRelativePath( 38 // @Nullable 39 final HttpServletRequest request) { 40 if (request != null) { 41 String contextPath = request.getContextPath(); 42 String requestURI = request.getRequestURI(); 43 if (contextPath.length() < requestURI.length()) { 44 return requestURI.substring(contextPath.length()); 45 } else if (requestURI != null && requestURI.trim().length() > 0 && 46 contextPath.length() == requestURI.length()) { 47 return "/"; 48 } 49 } 50 return null; 51 } 52 } 53
