| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.hadoop.security.token.delegation.web; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.http.NameValuePair; |
| import org.apache.http.client.utils.URLEncodedUtils; |
| |
| import javax.servlet.http.HttpServletRequest; |
| import java.io.IOException; |
| import java.nio.charset.Charset; |
| import java.util.List; |
| |
| /** |
| * Servlet utility methods. |
| */ |
| @InterfaceAudience.Private |
| class ServletUtils { |
| private static final Charset UTF8_CHARSET = Charset.forName("UTF-8"); |
| |
| /** |
| * Extract a query string parameter without triggering http parameters |
| * processing by the servlet container. |
| * |
| * @param request the request |
| * @param name the parameter to get the value. |
| * @return the parameter value, or <code>NULL</code> if the parameter is not |
| * defined. |
| * @throws IOException thrown if there was an error parsing the query string. |
| */ |
| public static String getParameter(HttpServletRequest request, String name) |
| throws IOException { |
| String queryString = request.getQueryString(); |
| if (queryString == null) { |
| return null; |
| } |
| List<NameValuePair> list = URLEncodedUtils.parse(queryString, UTF8_CHARSET); |
| if (list != null) { |
| for (NameValuePair nv : list) { |
| if (name.equals(nv.getName())) { |
| return nv.getValue(); |
| } |
| } |
| } |
| return null; |
| } |
| } |