1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.http.message;
29
30 import java.io.Serializable;
31 import java.util.ArrayList;
32 import java.util.Collections;
33 import java.util.Iterator;
34 import java.util.List;
35 import java.util.Locale;
36
37 import org.apache.hc.core5.http.Header;
38 import org.apache.hc.core5.http.MessageHeaders;
39 import org.apache.hc.core5.http.ProtocolException;
40 import org.apache.hc.core5.util.CharArrayBuffer;
41 import org.apache.hc.core5.util.LangUtils;
42
43 /**
44 * A class for combining a set of headers. This class allows for multiple headers with the same name
45 * and keeps track of the order in which headers were added.
46 *
47 * @since 4.0
48 */
49 public class HeaderGroup implements MessageHeaders, Serializable {
50
51 private static final long serialVersionUID = 2608834160639271617L;
52
53 private static final Headerp/Header.html#Header">Header[] EMPTY = new Header[] {};
54
55 /** The list of headers for this group, in the order in which they were added */
56 private final List<Header> headers;
57
58 /**
59 * Constructor for HeaderGroup.
60 */
61 public HeaderGroup() {
62 this.headers = new ArrayList<>(16);
63 }
64
65 /**
66 * Removes all headers.
67 */
68 public void clear() {
69 headers.clear();
70 }
71
72 /**
73 * Adds the given header to the group. The order in which this header was
74 * added is preserved.
75 *
76 * @param header the header to add
77 */
78 public void addHeader(final Header header) {
79 if (header == null) {
80 return;
81 }
82 headers.add(header);
83 }
84
85 /**
86 * Removes the first given header.
87 *
88 * @param header the header to remove
89 * @return <code>true</code> if a header was removed as a result of this call.
90 */
91 public boolean removeHeader(final Header header) {
92 if (header == null) {
93 return false;
94 }
95 for (int i = 0; i < this.headers.size(); i++) {
96 final Header current = this.headers.get(i);
97 if (headerEquals(header, current)) {
98 this.headers.remove(current);
99 return true;
100 }
101 }
102 return false;
103 }
104
105 private boolean headerEquals(final Header/Header.html#Header">Header header1, final Header header2) {
106 return header2 == header1 || header2.getName().equalsIgnoreCase(header1.getName())
107 && LangUtils.equals(header1.getValue(), header2.getValue());
108 }
109
110 /**
111 * Removes all headers that match the given header.
112 *
113 * @param header the header to remove
114 * @return <code>true</code> if any header was removed as a result of this call.
115 *
116 * @since 5.0
117 */
118 public boolean removeHeaders(final Header header) {
119 if (header == null) {
120 return false;
121 }
122 boolean removed = false;
123 for (final Iterator<Header> iterator = headerIterator(); iterator.hasNext();) {
124 final Header current = iterator.next();
125 if (headerEquals(header, current)) {
126 iterator.remove();
127 removed = true;
128 }
129 }
130 return removed;
131 }
132
133 /**
134 * Replaces the first occurrence of the header with the same name. If no header with
135 * the same name is found the given header is added to the end of the list.
136 *
137 * @param header the new header that should replace the first header with the same
138 * name if present in the list.
139 *
140 * @since 5.0
141 */
142 public void setHeader(final Header header) {
143 if (header == null) {
144 return;
145 }
146 for (int i = 0; i < this.headers.size(); i++) {
147 final Header current = this.headers.get(i);
148 if (current.getName().equalsIgnoreCase(header.getName())) {
149 this.headers.set(i, header);
150 return;
151 }
152 }
153 this.headers.add(header);
154 }
155
156 /**
157 * Sets all of the headers contained within this group overriding any
158 * existing headers. The headers are added in the order in which they appear
159 * in the array.
160 *
161 * @param headers the headers to set
162 */
163 public void setHeaders(final Header... headers) {
164 clear();
165 if (headers == null) {
166 return;
167 }
168 Collections.addAll(this.headers, headers);
169 }
170
171 /**
172 * Gets a header representing all of the header values with the given name.
173 * If more that one header with the given name exists the values will be
174 * combined with a ",".
175 *
176 * <p>Header name comparison is case insensitive.
177 *
178 * @param name the name of the header(s) to get
179 * @return a header with a condensed value or {@code null} if no
180 * headers by the given name are present
181 */
182 public Header getCondensedHeader(final String name) {
183 final Header[] hdrs = getHeaders(name);
184
185 if (hdrs.length == 0) {
186 return null;
187 } else if (hdrs.length == 1) {
188 return hdrs[0];
189 } else {
190 final CharArrayBufferffer.html#CharArrayBuffer">CharArrayBuffer valueBuffer = new CharArrayBuffer(128);
191 valueBuffer.append(hdrs[0].getValue());
192 for (int i = 1; i < hdrs.length; i++) {
193 valueBuffer.append(", ");
194 valueBuffer.append(hdrs[i].getValue());
195 }
196
197 return new BasicHeader(name.toLowerCase(Locale.ROOT), valueBuffer.toString());
198 }
199 }
200
201 /**
202 * Gets all of the headers with the given name. The returned array
203 * maintains the relative order in which the headers were added.
204 *
205 * <p>Header name comparison is case insensitive.
206 *
207 * @param name the name of the header(s) to get
208 *
209 * @return an array of length ≥ 0
210 */
211 @Override
212 public Header[] getHeaders(final String name) {
213 List<Header> headersFound = null;
214 for (int i = 0; i < this.headers.size(); i++) {
215 final Header header = this.headers.get(i);
216 if (header.getName().equalsIgnoreCase(name)) {
217 if (headersFound == null) {
218 headersFound = new ArrayList<>();
219 }
220 headersFound.add(header);
221 }
222 }
223 return headersFound != null ? headersFound.toArray(new Header[headersFound.size()]) : EMPTY;
224 }
225
226 /**
227 * Gets the first header with the given name.
228 *
229 * <p>Header name comparison is case insensitive.
230 *
231 * @param name the name of the header to get
232 * @return the first header or {@code null}
233 */
234 @Override
235 public Header getFirstHeader(final String name) {
236 for (int i = 0; i < this.headers.size(); i++) {
237 final Header header = this.headers.get(i);
238 if (header.getName().equalsIgnoreCase(name)) {
239 return header;
240 }
241 }
242 return null;
243 }
244
245 /**
246 * Gets single first header with the given name.
247 *
248 * <p>Header name comparison is case insensitive.
249 *
250 * @param name the name of the header to get
251 * @return the first header or {@code null}
252 * @throws ProtocolException in case multiple headers with the given name are found.
253 */
254 @Override
255 public Header getHeader(final String name) throws ProtocolException {
256 int count = 0;
257 Header singleHeader = null;
258 for (int i = 0; i < this.headers.size(); i++) {
259 final Header header = this.headers.get(i);
260 if (header.getName().equalsIgnoreCase(name)) {
261 singleHeader = header;
262 count++;
263 }
264 }
265 if (count > 1) {
266 throw new ProtocolException("multiple '%s' headers found", name);
267 }
268 return singleHeader;
269 }
270
271 /**
272 * Gets the last header with the given name.
273 *
274 * <p>Header name comparison is case insensitive.
275 *
276 * @param name the name of the header to get
277 * @return the last header or {@code null}
278 */
279 @Override
280 public Header getLastHeader(final String name) {
281 // start at the end of the list and work backwards
282 for (int i = headers.size() - 1; i >= 0; i--) {
283 final Header header = headers.get(i);
284 if (header.getName().equalsIgnoreCase(name)) {
285 return header;
286 }
287 }
288
289 return null;
290 }
291
292 /**
293 * Gets all of the headers contained within this group.
294 *
295 * @return an array of length ≥ 0
296 */
297 @Override
298 public Header[] getHeaders() {
299 return headers.toArray(new Header[headers.size()]);
300 }
301
302 /**
303 * Tests if headers with the given name are contained within this group.
304 *
305 * <p>Header name comparison is case insensitive.
306 *
307 * @param name the header name to test for
308 * @return {@code true} if at least one header with the name is
309 * contained, {@code false} otherwise
310 */
311 @Override
312 public boolean containsHeader(final String name) {
313 for (int i = 0; i < this.headers.size(); i++) {
314 final Header header = this.headers.get(i);
315 if (header.getName().equalsIgnoreCase(name)) {
316 return true;
317 }
318 }
319
320 return false;
321 }
322
323 /**
324 * Checks if a certain header is present in this message and how many times.
325 * <p>Header name comparison is case insensitive.
326 *
327 * @param name the header name to check for.
328 * @return number of occurrences of the header in the message.
329 */
330 @Override
331 public int countHeaders(final String name) {
332 int count = 0;
333 for (int i = 0; i < this.headers.size(); i++) {
334 final Header header = this.headers.get(i);
335 if (header.getName().equalsIgnoreCase(name)) {
336 count++;
337 }
338 }
339 return count;
340 }
341
342 /**
343 * Returns an iterator over this group of headers.
344 *
345 * @return iterator over this group of headers.
346 *
347 * @since 5.0
348 */
349 @Override
350 public Iterator<Header> headerIterator() {
351 return new BasicListHeaderIterator(this.headers, null);
352 }
353
354 /**
355 * Returns an iterator over the headers with a given name in this group.
356 *
357 * @param name the name of the headers over which to iterate, or
358 * {@code null} for all headers
359 *
360 * @return iterator over some headers in this group.
361 *
362 * @since 5.0
363 */
364 @Override
365 public Iterator<Header> headerIterator(final String name) {
366 return new BasicListHeaderIterator(this.headers, name);
367 }
368
369 /**
370 * Removes all headers with a given name in this group.
371 *
372 * @param name the name of the headers to be removed.
373 * @return <code>true</code> if any header was removed as a result of this call.
374 *
375 * @since 5.0
376 */
377 public boolean removeHeaders(final String name) {
378 if (name == null) {
379 return false;
380 }
381 boolean removed = false;
382 for (final Iterator<Header> iterator = headerIterator(); iterator.hasNext(); ) {
383 final Header header = iterator.next();
384 if (header.getName().equalsIgnoreCase(name)) {
385 iterator.remove();
386 removed = true;
387 }
388 }
389 return removed;
390 }
391
392 @Override
393 public String toString() {
394 return this.headers.toString();
395 }
396
397 }