org.apache.hadoop.security.token.delegation.web.ServletUtils Maven / Gradle / Ivy
/**
* 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 NULL 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 list = URLEncodedUtils.parse(queryString, UTF8_CHARSET);
if (list != null) {
for (NameValuePair nv : list) {
if (name.equals(nv.getName())) {
return nv.getValue();
}
}
}
return null;
}
}