/*
* ========================================================================
*
* 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.cactus.internal.server;
import java.net.URLDecoder;
import org.apache.cactus.util.ChainedRuntimeException;
/**
* All prupose utility methods for manipulating the Servlet API.
*
* @version $Id: ServletUtil.java 238991 2004-05-22 11:34:50Z vmassol $
*/
public class ServletUtil
{
/**
* A substitute method for <code>HttpServletRequest.getParameter()</code>.
* Contrary to <code>getParameter()</code>, this method does not
* access the request input stream (only the query string of the url).
*
* Note: We use this method internally to retrieve Cactus parameters passed
* by the client side. The issue with <code>getParameter()</code> is that
* if you use it, then you cannot call <code>getReader()</code> or
* <code>getInputStream()</code> (see the Servlet spec). However, if we
* want to allow for testing code that uses these 2 methods (and we do !)
* we need to use this method to get the internal Cactus parameters.
*
* @param theQueryString the query string to parse
* @param theParameter the name of the parameter to locate
* @return the value for theParameter in theQueryString, null if
* theParameter does not exist and "" if the parameter exists but
* has no value defined in the query string
*/
public static String getQueryStringParameter(String theQueryString,
String theParameter)
{
if (theQueryString == null)
{
return null;
}
String value = null;
int startIndex = theQueryString.indexOf(theParameter + "=");
if (startIndex >= 0)
{
// add 1 for '='
startIndex += (theParameter.length() + 1);
int endIndex = theQueryString.indexOf('&', startIndex);
if (endIndex > startIndex)
{
value = theQueryString.substring(startIndex, endIndex);
}
else if (endIndex == startIndex)
{
value = "";
}
else
{
value = theQueryString.substring(startIndex);
}
// In JDK 1.2 URLDecoder.decode throws an Exception. This is not
// needed for JDK 1.3+ but needed to keep JDK 1.2.2 compatibility
try
{
value = URLDecoder.decode(value);
}
catch (Exception e)
{
throw new ChainedRuntimeException("Error URL decoding ["
+ value + "]", e);
}
}
return value;
}
}