/*
* 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.tomcat.util.http;
/**
* Usefull methods for Content-Type processing
*
* @author James Duncan Davidson [duncan@eng.sun.com]
* @author James Todd [gonzo@eng.sun.com]
* @author Jason Hunter [jch@eng.sun.com]
* @author Harish Prabandham
* @author costin@eng.sun.com
*/
public class ContentType {
/**
* Parse the character encoding from the specified content type header.
* If the content type is null, or there is no explicit character encoding,
* <code>null</code> is returned.
*
* @param contentType a content type header
*/
public static String getCharsetFromContentType(String contentType) {
if (contentType == null)
return (null);
int start = contentType.indexOf("charset=");
if (start < 0)
return (null);
String encoding = contentType.substring(start + 8);
int end = encoding.indexOf(';');
if (end >= 0)
encoding = encoding.substring(0, end);
encoding = encoding.trim();
if ((encoding.length() > 2) && (encoding.startsWith("\""))
&& (encoding.endsWith("\"")))
encoding = encoding.substring(1, encoding.length() - 1);
return (encoding.trim());
}
/**
* Returns true if the given content type contains a charset component,
* false otherwise.
*
* @param type Content type
* @return true if the given content type contains a charset component,
* false otherwise
*/
public static boolean hasCharset(String type) {
boolean hasCharset = false;
int len = type.length();
int index = type.indexOf(';');
while (index != -1) {
index++;
while (index < len && Character.isSpace(type.charAt(index))) {
index++;
}
if (index+8 < len
&& type.charAt(index) == 'c'
&& type.charAt(index+1) == 'h'
&& type.charAt(index+2) == 'a'
&& type.charAt(index+3) == 'r'
&& type.charAt(index+4) == 's'
&& type.charAt(index+5) == 'e'
&& type.charAt(index+6) == 't'
&& type.charAt(index+7) == '=') {
hasCharset = true;
break;
}
index = type.indexOf(';', index);
}
return hasCharset;
}
}