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 /**
60 * Constructor for HeaderGroup.
61 */
62 public HeaderGroup() {
63 this.headers = new ArrayList<>(16);
64 }
65
66 /**
67 * Removes all headers.
68 */
69 public void clear() {
70 headers.clear();
71 }
72
73 /**
74 * Adds the given header to the group. The order in which this header was
75 * added is preserved.
76 *
77 * @param header the header to add
78 */
79 public void addHeader(final Header header) {
80 if (header == null) {
81 return;
82 }
83 headers.add(header);
84 }
85
86 /**
87 * Removes the first given header.
88 *
89 * @param header the header to remove
90 * @return <code>true</code> if a header was removed as a result of this call.
91 */
92 public boolean removeHeader(final Header header) {
93 if (header == null) {
94 return false;
95 }
96 for (int i = 0; i < this.headers.size(); i++) {
97 final Header current = this.headers.get(i);
98 if (headerEquals(header, current)) {
99 this.headers.remove(current);
100 return true;
101 }
102 }
103 return false;
104 }
105
106 private boolean headerEquals(final Header/Header.html#Header">Header header1, final Header header2) {
107 return header2 == header1 || header2.getName().equalsIgnoreCase(header1.getName())
108 && LangUtils.equals(header1.getValue(), header2.getValue());
109 }
110
111 /**
112 * Removes all headers that match the given header.
113 *
114 * @param header the header to remove
115 * @return <code>true</code> if any header was removed as a result of this call.
116 *
117 * @since 5.0
118 */
119 public boolean removeHeaders(final Header header) {
120 if (header == null) {
121 return false;
122 }
123 boolean removed = false;
124 for (final Iterator<Header> iterator = headerIterator(); iterator.hasNext();) {
125 final Header current = iterator.next();
126 if (headerEquals(header, current)) {
127 iterator.remove();
128 removed = true;
129 }
130 }
131 return removed;
132 }
133
134 /**
135 * Replaces the first occurrence of the header with the same name. If no header with
136 * the same name is found the given header is added to the end of the list.
137 *
138 * @param header the new header that should replace the first header with the same
139 * name if present in the list.
140 *
141 * @since 5.0
142 */
143 public void setHeader(final Header header) {
144 if (header == null) {
145 return;
146 }
147 for (int i = 0; i < this.headers.size(); i++) {
148 final Header current = this.headers.get(i);
149 if (current.getName().equalsIgnoreCase(header.getName())) {
150 this.headers.set(i, header);
151 return;
152 }
153 }
154 this.headers.add(header);
155 }
156
157 /**
158 * Sets all of the headers contained within this group overriding any
159 * existing headers. The headers are added in the order in which they appear
160 * in the array.
161 *
162 * @param headers the headers to set
163 */
164 public void setHeaders(final Header... headers) {
165 clear();
166 if (headers == null) {
167 return;
168 }
169 Collections.addAll(this.headers, headers);
170 }
171
172 /**
173 * Gets a header representing all of the header values with the given name.
174 * If more that one header with the given name exists the values will be
175 * combined with a ",".
176 *
177 * <p>Header name comparison is case insensitive.
178 *
179 * @param name the name of the header(s) to get
180 * @return a header with a condensed value or {@code null} if no
181 * headers by the given name are present
182 */
183 public Header getCondensedHeader(final String name) {
184 final Header[] hdrs = getHeaders(name);
185
186 if (hdrs.length == 0) {
187 return null;
188 } else if (hdrs.length == 1) {
189 return hdrs[0];
190 } else {
191 final CharArrayBufferffer.html#CharArrayBuffer">CharArrayBuffer valueBuffer = new CharArrayBuffer(128);
192 valueBuffer.append(hdrs[0].getValue());
193 for (int i = 1; i < hdrs.length; i++) {
194 valueBuffer.append(", ");
195 valueBuffer.append(hdrs[i].getValue());
196 }
197
198 return new BasicHeader(name.toLowerCase(Locale.ROOT), valueBuffer.toString());
199 }
200 }
201
202 /**
203 * Gets all of the headers with the given name. The returned array
204 * maintains the relative order in which the headers were added.
205 *
206 * <p>Header name comparison is case insensitive.
207 *
208 * @param name the name of the header(s) to get
209 *
210 * @return an array of length ≥ 0
211 */
212 @Override
213 public Header[] getHeaders(final String name) {
214 List<Header> headersFound = null;
215 for (int i = 0; i < this.headers.size(); i++) {
216 final Header header = this.headers.get(i);
217 if (header.getName().equalsIgnoreCase(name)) {
218 if (headersFound == null) {
219 headersFound = new ArrayList<>();
220 }
221 headersFound.add(header);
222 }
223 }
224 return headersFound != null ? headersFound.toArray(EMPTY) : EMPTY;
225 }
226
227 /**
228 * Gets the first header with the given name.
229 *
230 * <p>Header name comparison is case insensitive.
231 *
232 * @param name the name of the header to get
233 * @return the first header or {@code null}
234 */
235 @Override
236 public Header getFirstHeader(final String name) {
237 for (int i = 0; i < this.headers.size(); i++) {
238 final Header header = this.headers.get(i);
239 if (header.getName().equalsIgnoreCase(name)) {
240 return header;
241 }
242 }
243 return null;
244 }
245
246 /**
247 * Gets single first header with the given name.
248 *
249 * <p>Header name comparison is case insensitive.
250 *
251 * @param name the name of the header to get
252 * @return the first header or {@code null}
253 * @throws ProtocolException in case multiple headers with the given name are found.
254 */
255 @Override
256 public Header getHeader(final String name) throws ProtocolException {
257 int count = 0;
258 Header singleHeader = null;
259 for (int i = 0; i < this.headers.size(); i++) {
260 final Header header = this.headers.get(i);
261 if (header.getName().equalsIgnoreCase(name)) {
262 singleHeader = header;
263 count++;
264 }
265 }
266 if (count > 1) {
267 throw new ProtocolException("multiple '%s' headers found", name);
268 }
269 return singleHeader;
270 }
271
272 /**
273 * Gets the last header with the given name.
274 *
275 * <p>Header name comparison is case insensitive.
276 *
277 * @param name the name of the header to get
278 * @return the last header or {@code null}
279 */
280 @Override
281 public Header getLastHeader(final String name) {
282 // start at the end of the list and work backwards
283 for (int i = headers.size() - 1; i >= 0; i--) {
284 final Header header = headers.get(i);
285 if (header.getName().equalsIgnoreCase(name)) {
286 return header;
287 }
288 }
289
290 return null;
291 }
292
293 /**
294 * Gets all of the headers contained within this group.
295 *
296 * @return an array of length ≥ 0
297 */
298 @Override
299 public Header[] getHeaders() {
300 return headers.toArray(EMPTY);
301 }
302
303 /**
304 * Tests if headers with the given name are contained within this group.
305 *
306 * <p>Header name comparison is case insensitive.
307 *
308 * @param name the header name to test for
309 * @return {@code true} if at least one header with the name is
310 * contained, {@code false} otherwise
311 */
312 @Override
313 public boolean containsHeader(final String name) {
314 for (int i = 0; i < this.headers.size(); i++) {
315 final Header header = this.headers.get(i);
316 if (header.getName().equalsIgnoreCase(name)) {
317 return true;
318 }
319 }
320
321 return false;
322 }
323
324 /**
325 * Checks if a certain header is present in this message and how many times.
326 * <p>Header name comparison is case insensitive.
327 *
328 * @param name the header name to check for.
329 * @return number of occurrences of the header in the message.
330 */
331 @Override
332 public int countHeaders(final String name) {
333 int count = 0;
334 for (int i = 0; i < this.headers.size(); i++) {
335 final Header header = this.headers.get(i);
336 if (header.getName().equalsIgnoreCase(name)) {
337 count++;
338 }
339 }
340 return count;
341 }
342
343 /**
344 * Returns an iterator over this group of headers.
345 *
346 * @return iterator over this group of headers.
347 *
348 * @since 5.0
349 */
350 @Override
351 public Iterator<Header> headerIterator() {
352 return new BasicListHeaderIterator(this.headers, null);
353 }
354
355 /**
356 * Returns an iterator over the headers with a given name in this group.
357 *
358 * @param name the name of the headers over which to iterate, or
359 * {@code null} for all headers
360 *
361 * @return iterator over some headers in this group.
362 *
363 * @since 5.0
364 */
365 @Override
366 public Iterator<Header> headerIterator(final String name) {
367 return new BasicListHeaderIterator(this.headers, name);
368 }
369
370 /**
371 * Removes all headers with a given name in this group.
372 *
373 * @param name the name of the headers to be removed.
374 * @return <code>true</code> if any header was removed as a result of this call.
375 *
376 * @since 5.0
377 */
378 public boolean removeHeaders(final String name) {
379 if (name == null) {
380 return false;
381 }
382 boolean removed = false;
383 for (final Iterator<Header> iterator = headerIterator(); iterator.hasNext(); ) {
384 final Header header = iterator.next();
385 if (header.getName().equalsIgnoreCase(name)) {
386 iterator.remove();
387 removed = true;
388 }
389 }
390 return removed;
391 }
392
393 @Override
394 public String toString() {
395 return this.headers.toString();
396 }
397
398 }