001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.xbean.osgi.bundle.util; 019 020import java.util.List; 021import java.util.Map; 022import java.util.regex.Pattern; 023 024import org.apache.xbean.osgi.bundle.util.HeaderParser.HeaderElement; 025 026/** 027 * @version $Rev: 1160977 $ $Date: 2011-08-24 07:02:21 +0200 (Wed, 24 Aug 2011) $ 028 */ 029public class HeaderBuilder { 030 031 private static final Pattern EXTENDED_PATTERN = Pattern.compile("[\\w_\\-\\.]+"); 032 033 public static String build(List<HeaderElement> headerElements) { 034 if (headerElements == null || headerElements.size() == 0) { 035 return ""; 036 } 037 StringBuilder header = new StringBuilder(); 038 for (HeaderElement headerElement : headerElements) { 039 String name = headerElement.getName(); 040 if (name == null || name.length() == 0) { 041 throw new IllegalArgumentException("Invalid header name for the header elment " + headerElement); 042 } 043 if (header.length() > 0) { 044 header.append(","); 045 } 046 header.append(name); 047 for (Map.Entry<String, String> attribute : headerElement.getAttributes().entrySet()) { 048 header.append(";").append(attribute.getKey()).append("="); 049 if (EXTENDED_PATTERN.matcher(attribute.getValue()).matches()) { 050 header.append(attribute.getValue()); 051 } else { 052 header.append("\"").append(attribute.getValue()).append("\""); 053 } 054 } 055 for (Map.Entry<String, String> directive : headerElement.getDirectives().entrySet()) { 056 header.append(";").append(directive.getKey()).append(":="); 057 if (EXTENDED_PATTERN.matcher(directive.getValue()).matches()) { 058 header.append(directive.getValue()); 059 } else { 060 header.append("\"").append(directive.getValue()).append("\""); 061 } 062 } 063 } 064 return header.toString(); 065 } 066}