001 /****************************************************************
002 * Licensed to the Apache Software Foundation (ASF) under one *
003 * or more contributor license agreements. See the NOTICE file *
004 * distributed with this work for additional information *
005 * regarding copyright ownership. The ASF licenses this file *
006 * to you under the Apache License, Version 2.0 (the *
007 * "License"); you may not use this file except in compliance *
008 * with the License. You may obtain a copy of the License at *
009 * *
010 * http://www.apache.org/licenses/LICENSE-2.0 *
011 * *
012 * Unless required by applicable law or agreed to in writing, *
013 * software distributed under the License is distributed on an *
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
015 * KIND, either express or implied. See the License for the *
016 * specific language governing permissions and limitations *
017 * under the License. *
018 ****************************************************************/
019
020 package org.apache.james.mime4j.message;
021
022 import java.util.Collections;
023 import java.util.HashMap;
024 import java.util.Iterator;
025 import java.util.LinkedList;
026 import java.util.List;
027 import java.util.Map;
028
029 import org.apache.james.mime4j.dom.Header;
030 import org.apache.james.mime4j.stream.Field;
031
032 /**
033 * Abstract MIME header.
034 */
035 public abstract class AbstractHeader implements Header {
036
037 private List<Field> fields = new LinkedList<Field>();
038 private Map<String, List<Field>> fieldMap = new HashMap<String, List<Field>>();
039
040 /**
041 * Creates a new empty <code>Header</code>.
042 */
043 public AbstractHeader() {
044 }
045
046 /**
047 * Creates a new <code>Header</code> from the specified
048 * <code>Header</code>. The <code>Header</code> instance is initialized
049 * with a copy of the list of {@link Field}s of the specified
050 * <code>Header</code>. The <code>Field</code> objects are not copied
051 * because they are immutable and can safely be shared between headers.
052 *
053 * @param other
054 * header to copy.
055 */
056 public AbstractHeader(Header other) {
057 for (Field otherField : other.getFields()) {
058 addField(otherField);
059 }
060 }
061
062 /**
063 * Adds a field to the end of the list of fields.
064 *
065 * @param field the field to add.
066 */
067 public void addField(Field field) {
068 List<Field> values = fieldMap.get(field.getName().toLowerCase());
069 if (values == null) {
070 values = new LinkedList<Field>();
071 fieldMap.put(field.getName().toLowerCase(), values);
072 }
073 values.add(field);
074 fields.add(field);
075 }
076
077 /**
078 * Gets the fields of this header. The returned list will not be
079 * modifiable.
080 *
081 * @return the list of <code>Field</code> objects.
082 */
083 public List<Field> getFields() {
084 return Collections.unmodifiableList(fields);
085 }
086
087 /**
088 * Gets a <code>Field</code> given a field name. If there are multiple
089 * such fields defined in this header the first one will be returned.
090 *
091 * @param name the field name (e.g. From, Subject).
092 * @return the field or <code>null</code> if none found.
093 */
094 public Field getField(String name) {
095 List<Field> l = fieldMap.get(name.toLowerCase());
096 if (l != null && !l.isEmpty()) {
097 return l.get(0);
098 }
099 return null;
100 }
101
102 /**
103 * Gets all <code>Field</code>s having the specified field name.
104 *
105 * @param name the field name (e.g. From, Subject).
106 * @return the list of fields.
107 */
108 public List<Field> getFields(final String name) {
109 final String lowerCaseName = name.toLowerCase();
110 final List<Field> l = fieldMap.get(lowerCaseName);
111 final List<Field> results;
112 if (l == null || l.isEmpty()) {
113 results = Collections.emptyList();
114 } else {
115 results = Collections.unmodifiableList(l);
116 }
117 return results;
118 }
119
120 /**
121 * Returns an iterator over the list of fields of this header.
122 *
123 * @return an iterator.
124 */
125 public Iterator<Field> iterator() {
126 return Collections.unmodifiableList(fields).iterator();
127 }
128
129 /**
130 * Removes all <code>Field</code>s having the specified field name.
131 *
132 * @param name
133 * the field name (e.g. From, Subject).
134 * @return number of fields removed.
135 */
136 public int removeFields(String name) {
137 final String lowerCaseName = name.toLowerCase();
138 List<Field> removed = fieldMap.remove(lowerCaseName);
139 if (removed == null || removed.isEmpty())
140 return 0;
141
142 for (Iterator<Field> iterator = fields.iterator(); iterator.hasNext();) {
143 Field field = iterator.next();
144 if (field.getName().equalsIgnoreCase(name))
145 iterator.remove();
146 }
147
148 return removed.size();
149 }
150
151 /**
152 * Sets or replaces a field. This method is useful for header fields such as
153 * Subject or Message-ID that should not occur more than once in a message.
154 *
155 * If this <code>Header</code> does not already contain a header field of
156 * the same name as the given field then it is added to the end of the list
157 * of fields (same behavior as {@link #addField(Field)}). Otherwise the
158 * first occurrence of a field with the same name is replaced by the given
159 * field and all further occurrences are removed.
160 *
161 * @param field the field to set.
162 */
163 public void setField(Field field) {
164 final String lowerCaseName = field.getName().toLowerCase();
165 List<Field> l = fieldMap.get(lowerCaseName);
166 if (l == null || l.isEmpty()) {
167 addField(field);
168 return;
169 }
170
171 l.clear();
172 l.add(field);
173
174 int firstOccurrence = -1;
175 int index = 0;
176 for (Iterator<Field> iterator = fields.iterator(); iterator.hasNext(); index++) {
177 Field f = iterator.next();
178 if (f.getName().equalsIgnoreCase(field.getName())) {
179 iterator.remove();
180
181 if (firstOccurrence == -1)
182 firstOccurrence = index;
183 }
184 }
185
186 fields.add(firstOccurrence, field);
187 }
188
189 /**
190 * Return Header Object as String representation. Each headerline is
191 * seperated by "\r\n"
192 *
193 * @return headers
194 */
195 @Override
196 public String toString() {
197 StringBuilder str = new StringBuilder(128);
198 for (Field field : fields) {
199 str.append(field.toString());
200 str.append("\r\n");
201 }
202 return str.toString();
203 }
204
205 }