/*
* 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.activemq.transport.amqp.message;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.StandardCharsets;
import java.nio.charset.UnsupportedCharsetException;
import java.util.StringTokenizer;
public final class AmqpContentTypeSupport {
private static final String UTF_8 = "UTF-8";
private static final String CHARSET = "charset";
private static final String TEXT = "text";
private static final String APPLICATION = "application";
private static final String JAVASCRIPT = "javascript";
private static final String XML = "xml";
private static final String XML_VARIANT = "+xml";
private static final String JSON = "json";
private static final String JSON_VARIANT = "+json";
private static final String XML_DTD = "xml-dtd";
private static final String ECMASCRIPT = "ecmascript";
/**
* @param contentType
* the contentType of the received message
* @return the character set to use, or null if not to treat the message as
* text
* @throws InvalidContentTypeException
* if the content-type is invalid in some way.
*/
public static Charset parseContentTypeForTextualCharset(final String contentType) throws InvalidContentTypeException {
if (contentType == null || contentType.trim().isEmpty()) {
throw new InvalidContentTypeException("Content type can't be null or empty");
}
int subTypeSeparator = contentType.indexOf("/");
if (subTypeSeparator == -1) {
throw new InvalidContentTypeException("Content type has no '/' separator: " + contentType);
}
final String type = contentType.substring(0, subTypeSeparator).toLowerCase().trim();
String subTypePart = contentType.substring(subTypeSeparator + 1).toLowerCase().trim();
String parameterPart = null;
int parameterSeparator = subTypePart.indexOf(";");
if (parameterSeparator != -1) {
if (parameterSeparator < subTypePart.length() - 1) {
parameterPart = contentType.substring(subTypeSeparator + 1).toLowerCase().trim();
}
subTypePart = subTypePart.substring(0, parameterSeparator).trim();
}
if (subTypePart.isEmpty()) {
throw new InvalidContentTypeException("Content type has no subtype after '/'" + contentType);
}
final String subType = subTypePart;
if (isTextual(type, subType)) {
String charset = findCharset(parameterPart);
if (charset == null) {
charset = UTF_8;
}
if (UTF_8.equals(charset)) {
return StandardCharsets.UTF_8;
} else {
try {
return Charset.forName(charset);
} catch (IllegalCharsetNameException icne) {
throw new InvalidContentTypeException("Illegal charset: " + charset);
} catch (UnsupportedCharsetException uce) {
throw new InvalidContentTypeException("Unsupported charset: " + charset);
}
}
}
return null;
}
//----- Internal Content Type utilities ----------------------------------//
private static boolean isTextual(String type, String subType) {
if (TEXT.equals(type)) {
return true;
}
if (APPLICATION.equals(type)) {
if (XML.equals(subType) || JSON.equals(subType) || JAVASCRIPT.equals(subType) || subType.endsWith(XML_VARIANT) || subType.endsWith(JSON_VARIANT)
|| XML_DTD.equals(subType) || ECMASCRIPT.equals(subType)) {
return true;
}
}
return false;
}
private static String findCharset(String paramaterPart) {
String charset = null;
if (paramaterPart != null) {
StringTokenizer tokenizer = new StringTokenizer(paramaterPart, ";");
while (tokenizer.hasMoreTokens()) {
String parameter = tokenizer.nextToken().trim();
int eqIndex = parameter.indexOf('=');
if (eqIndex != -1) {
String name = parameter.substring(0, eqIndex);
if (CHARSET.equalsIgnoreCase(name.trim())) {
String value = unquote(parameter.substring(eqIndex + 1));
charset = value.toUpperCase();
break;
}
}
}
}
return charset;
}
private static String unquote(String s) {
if (s.length() > 1 && (s.startsWith("\"") && s.endsWith("\""))) {
return s.substring(1, s.length() - 1);
} else {
return s;
}
}
}