001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.tools;
003
004import static org.openstreetmap.josm.tools.I18n.tr;
005
006import java.io.BufferedReader;
007import java.io.IOException;
008import java.io.InputStream;
009import java.net.CookieHandler;
010import java.net.CookieManager;
011import java.net.HttpURLConnection;
012import java.net.MalformedURLException;
013import java.net.URL;
014import java.nio.charset.StandardCharsets;
015import java.util.List;
016import java.util.Locale;
017import java.util.Map;
018import java.util.Objects;
019import java.util.Scanner;
020import java.util.TreeMap;
021import java.util.concurrent.TimeUnit;
022import java.util.regex.Matcher;
023import java.util.regex.Pattern;
024import java.util.zip.GZIPInputStream;
025
026import org.openstreetmap.josm.data.validation.routines.DomainValidator;
027import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
028import org.openstreetmap.josm.gui.progress.ProgressMonitor;
029import org.openstreetmap.josm.io.Compression;
030import org.openstreetmap.josm.io.NetworkManager;
031import org.openstreetmap.josm.io.ProgressInputStream;
032import org.openstreetmap.josm.io.UTFInputStreamReader;
033import org.openstreetmap.josm.io.auth.DefaultAuthenticator;
034import org.openstreetmap.josm.spi.preferences.Config;
035
036/**
037 * Provides a uniform access for a HTTP/HTTPS server. This class should be used in favour of {@link HttpURLConnection}.
038 * @since 9168
039 */
040public abstract class HttpClient {
041
042    /**
043     * HTTP client factory.
044     * @since 15229
045     */
046    @FunctionalInterface
047    public interface HttpClientFactory {
048        /**
049         * Creates a new instance for the given URL and a {@code GET} request
050         *
051         * @param url the URL
052         * @param requestMethod the HTTP request method to perform when calling
053         * @return a new instance
054         */
055        HttpClient create(URL url, String requestMethod);
056    }
057
058    private URL url;
059    private final String requestMethod;
060    private int connectTimeout = (int) TimeUnit.SECONDS.toMillis(Config.getPref().getInt("socket.timeout.connect", 15));
061    private int readTimeout = (int) TimeUnit.SECONDS.toMillis(Config.getPref().getInt("socket.timeout.read", 30));
062    private byte[] requestBody;
063    private long ifModifiedSince;
064    private final Map<String, String> headers = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
065    private int maxRedirects = Config.getPref().getInt("socket.maxredirects", 5);
066    private boolean useCache;
067    private String reasonForRequest;
068    private String outputMessage = tr("Uploading data ...");
069    private Response response;
070    private boolean finishOnCloseOutput = true;
071    private boolean debug;
072
073    // Pattern to detect Tomcat error message. Be careful with change of format:
074    // CHECKSTYLE.OFF: LineLength
075    // https://svn.apache.org/viewvc/tomcat/trunk/java/org/apache/catalina/valves/ErrorReportValve.java?r1=1740707&r2=1779641&pathrev=1779641&diff_format=h
076    // CHECKSTYLE.ON: LineLength
077    private static final Pattern TOMCAT_ERR_MESSAGE = Pattern.compile(
078        ".*<p><b>[^<]+</b>[^<]+</p><p><b>[^<]+</b> (?:<u>)?([^<]*)(?:</u>)?</p><p><b>[^<]+</b> (?:<u>)?[^<]*(?:</u>)?</p>.*",
079        Pattern.CASE_INSENSITIVE);
080
081    private static HttpClientFactory factory;
082
083    static {
084        try {
085            CookieHandler.setDefault(new CookieManager());
086        } catch (SecurityException e) {
087            Logging.log(Logging.LEVEL_ERROR, "Unable to set default cookie handler", e);
088        }
089    }
090
091    /**
092     * Registers a new HTTP client factory.
093     * @param newFactory new HTTP client factory
094     * @since 15229
095     */
096    public static void setFactory(HttpClientFactory newFactory) {
097        factory = Objects.requireNonNull(newFactory);
098    }
099
100    /**
101     * Constructs a new {@code HttpClient}.
102     * @param url URL to access
103     * @param requestMethod HTTP request method (GET, POST, PUT, DELETE...)
104     */
105    protected HttpClient(URL url, String requestMethod) {
106        try {
107            String host = url.getHost();
108            String asciiHost = DomainValidator.unicodeToASCII(host);
109            this.url = asciiHost.equals(host) ? url : new URL(url.getProtocol(), asciiHost, url.getPort(), url.getFile());
110        } catch (MalformedURLException e) {
111            throw new JosmRuntimeException(e);
112        }
113        this.requestMethod = requestMethod;
114        this.headers.put("Accept-Encoding", "gzip");
115    }
116
117    /**
118     * Opens the HTTP connection.
119     * @return HTTP response
120     * @throws IOException if any I/O error occurs
121     */
122    public final Response connect() throws IOException {
123        return connect(null);
124    }
125
126    /**
127     * Opens the HTTP connection.
128     * @param progressMonitor progress monitor
129     * @return HTTP response
130     * @throws IOException if any I/O error occurs
131     * @since 9179
132     */
133    public final Response connect(ProgressMonitor progressMonitor) throws IOException {
134        if (progressMonitor == null) {
135            progressMonitor = NullProgressMonitor.INSTANCE;
136        }
137        setupConnection(progressMonitor);
138
139        boolean successfulConnection = false;
140        try {
141            ConnectionResponse cr;
142            try {
143                cr = performConnection();
144                final boolean hasReason = reasonForRequest != null && !reasonForRequest.isEmpty();
145                logRequest("{0} {1}{2} -> {3} {4}{5}",
146                        getRequestMethod(), getURL(), hasReason ? (" (" + reasonForRequest + ')') : "",
147                        cr.getResponseVersion(), cr.getResponseCode(),
148                        cr.getContentLengthLong() > 0
149                                ? (" (" + Utils.getSizeString(cr.getContentLengthLong(), Locale.getDefault()) + ')')
150                                : ""
151                );
152                if (Logging.isDebugEnabled()) {
153                    try {
154                        Logging.debug("RESPONSE: {0}", cr.getHeaderFields());
155                    } catch (IllegalArgumentException e) {
156                        Logging.warn(e);
157                    }
158                }
159                if (DefaultAuthenticator.getInstance().isEnabled() && cr.getResponseCode() == HttpURLConnection.HTTP_UNAUTHORIZED) {
160                    DefaultAuthenticator.getInstance().addFailedCredentialHost(url.getHost());
161                }
162            } catch (IOException | RuntimeException e) {
163                logRequest("{0} {1} -> !!!", requestMethod, url);
164                Logging.warn(e);
165                //noinspection ThrowableResultOfMethodCallIgnored
166                NetworkManager.addNetworkError(url, Utils.getRootCause(e));
167                throw e;
168            }
169            if (isRedirect(cr.getResponseCode())) {
170                final String redirectLocation = cr.getHeaderField("Location");
171                if (redirectLocation == null) {
172                    /* I18n: argument is HTTP response code */
173                    throw new IOException(tr("Unexpected response from HTTP server. Got {0} response without ''Location'' header." +
174                            " Can''t redirect. Aborting.", cr.getResponseCode()));
175                } else if (maxRedirects > 0) {
176                    url = new URL(url, redirectLocation);
177                    maxRedirects--;
178                    logRequest(tr("Download redirected to ''{0}''", redirectLocation));
179                    response = connect();
180                    successfulConnection = true;
181                    return response;
182                } else if (maxRedirects == 0) {
183                    String msg = tr("Too many redirects to the download URL detected. Aborting.");
184                    throw new IOException(msg);
185                }
186            }
187            response = buildResponse(progressMonitor);
188            successfulConnection = true;
189            return response;
190        } finally {
191            if (!successfulConnection) {
192                performDisconnection();
193            }
194        }
195    }
196
197    protected abstract void setupConnection(ProgressMonitor progressMonitor) throws IOException;
198
199    protected abstract ConnectionResponse performConnection() throws IOException;
200
201    protected abstract void performDisconnection() throws IOException;
202
203    protected abstract Response buildResponse(ProgressMonitor progressMonitor) throws IOException;
204
205    protected final void notifyConnect(ProgressMonitor progressMonitor) {
206        progressMonitor.beginTask(tr("Contacting Server..."), 1);
207        progressMonitor.indeterminateSubTask(null);
208    }
209
210    protected final void logRequest(String pattern, Object... args) {
211        if (debug) {
212            Logging.debug(pattern, args);
213        } else {
214            Logging.info(pattern, args);
215        }
216    }
217
218    protected final void logRequestBody() {
219        logRequest("{0} {1} ({2}) ...", requestMethod, url, Utils.getSizeString(requestBody.length, Locale.getDefault()));
220        if (Logging.isTraceEnabled() && hasRequestBody()) {
221            Logging.trace("BODY: {0}", new String(requestBody, StandardCharsets.UTF_8));
222        }
223    }
224
225    /**
226     * Returns the HTTP response which is set only after calling {@link #connect()}.
227     * Calling this method again, returns the identical object (unless another {@link #connect()} is performed).
228     *
229     * @return the HTTP response
230     * @since 9309
231     */
232    public final Response getResponse() {
233        return response;
234    }
235
236    /**
237     * A wrapper for the HTTP connection response.
238     * @since 15229
239     */
240    public interface ConnectionResponse {
241        /**
242         * Gets the HTTP version from the HTTP response.
243         * @return the HTTP version from the HTTP response
244         */
245        String getResponseVersion();
246
247        /**
248         * Gets the status code from an HTTP response message.
249         * For example, in the case of the following status lines:
250         * <PRE>
251         * HTTP/1.0 200 OK
252         * HTTP/1.0 401 Unauthorized
253         * </PRE>
254         * It will return 200 and 401 respectively.
255         * Returns -1 if no code can be discerned
256         * from the response (i.e., the response is not valid HTTP).
257         * @return the HTTP Status-Code, or -1
258         * @throws IOException if an error occurred connecting to the server.
259         */
260        int getResponseCode() throws IOException;
261
262        /**
263         * Returns the value of the {@code content-length} header field as a long.
264         *
265         * @return  the content length of the resource that this connection's URL
266         *          references, or {@code -1} if the content length is not known.
267         */
268        long getContentLengthLong();
269
270        /**
271         * Returns an unmodifiable Map of the header fields.
272         * The Map keys are Strings that represent the response-header field names.
273         * Each Map value is an unmodifiable List of Strings that represents
274         * the corresponding field values.
275         *
276         * @return a Map of header fields
277         */
278        Map<String, List<String>> getHeaderFields();
279
280        /**
281         * Returns the value of the named header field.
282         * @param name the name of a header field.
283         * @return the value of the named header field, or {@code null}
284         *          if there is no such field in the header.
285         */
286        String getHeaderField(String name);
287    }
288
289    /**
290     * A wrapper for the HTTP response.
291     */
292    public abstract static class Response {
293        private final ProgressMonitor monitor;
294        private final int responseCode;
295        private final String responseMessage;
296        private boolean uncompress;
297        private boolean uncompressAccordingToContentDisposition;
298        private String responseData;
299
300        protected Response(ProgressMonitor monitor, int responseCode, String responseMessage) {
301            this.monitor = Objects.requireNonNull(monitor, "monitor");
302            this.responseCode = responseCode;
303            this.responseMessage = responseMessage;
304        }
305
306        protected final void debugRedirect() throws IOException {
307            if (responseCode >= 300) {
308                String contentType = getContentType();
309                if (contentType == null ||
310                    contentType.contains("text") ||
311                    contentType.contains("html") ||
312                    contentType.contains("xml")
313                ) {
314                    String content = fetchContent();
315                    Logging.debug(content.isEmpty() ? "Server did not return any body" : "Response body: \n" + content);
316                } else {
317                    Logging.debug("Server returned content: {0} of length: {1}. Not printing.", contentType, getContentLength());
318                }
319            }
320        }
321
322        /**
323         * Sets whether {@link #getContent()} should uncompress the input stream if necessary.
324         *
325         * @param uncompress whether the input stream should be uncompressed if necessary
326         * @return {@code this}
327         */
328        public final Response uncompress(boolean uncompress) {
329            this.uncompress = uncompress;
330            return this;
331        }
332
333        /**
334         * Sets whether {@link #getContent()} should uncompress the input stream according to {@code Content-Disposition}
335         * HTTP header.
336         * @param uncompressAccordingToContentDisposition whether the input stream should be uncompressed according to
337         * {@code Content-Disposition}
338         * @return {@code this}
339         * @since 9172
340         */
341        public final Response uncompressAccordingToContentDisposition(boolean uncompressAccordingToContentDisposition) {
342            this.uncompressAccordingToContentDisposition = uncompressAccordingToContentDisposition;
343            return this;
344        }
345
346        /**
347         * Returns the URL.
348         * @return the URL
349         * @see HttpURLConnection#getURL()
350         * @since 9172
351         */
352        public abstract URL getURL();
353
354        /**
355         * Returns the request method.
356         * @return the HTTP request method
357         * @see HttpURLConnection#getRequestMethod()
358         * @since 9172
359         */
360        public abstract String getRequestMethod();
361
362        /**
363         * Returns an input stream that reads from this HTTP connection, or,
364         * error stream if the connection failed but the server sent useful data.
365         * <p>
366         * Note: the return value can be null, if both the input and the error stream are null.
367         * Seems to be the case if the OSM server replies a 401 Unauthorized, see #3887
368         * @return input or error stream
369         * @throws IOException if any I/O error occurs
370         *
371         * @see HttpURLConnection#getInputStream()
372         * @see HttpURLConnection#getErrorStream()
373         */
374        @SuppressWarnings("resource")
375        public final InputStream getContent() throws IOException {
376            InputStream in = getInputStream();
377            in = new ProgressInputStream(in, getContentLength(), monitor);
378            in = "gzip".equalsIgnoreCase(getContentEncoding()) ? new GZIPInputStream(in) : in;
379            Compression compression = Compression.NONE;
380            if (uncompress) {
381                final String contentType = getContentType();
382                Logging.debug("Uncompressing input stream according to Content-Type header: {0}", contentType);
383                compression = Compression.forContentType(contentType);
384            }
385            if (uncompressAccordingToContentDisposition && Compression.NONE == compression) {
386                final String contentDisposition = getHeaderField("Content-Disposition");
387                final Matcher matcher = Pattern.compile("filename=\"([^\"]+)\"").matcher(
388                        contentDisposition != null ? contentDisposition : "");
389                if (matcher.find()) {
390                    Logging.debug("Uncompressing input stream according to Content-Disposition header: {0}", contentDisposition);
391                    compression = Compression.byExtension(matcher.group(1));
392                }
393            }
394            in = compression.getUncompressedInputStream(in);
395            return in;
396        }
397
398        protected abstract InputStream getInputStream() throws IOException;
399
400        /**
401         * Returns {@link #getContent()} wrapped in a buffered reader.
402         *
403         * Detects Unicode charset in use utilizing {@link UTFInputStreamReader}.
404         * @return buffered reader
405         * @throws IOException if any I/O error occurs
406         */
407        public final BufferedReader getContentReader() throws IOException {
408            return new BufferedReader(
409                    UTFInputStreamReader.create(getContent())
410            );
411        }
412
413        /**
414         * Fetches the HTTP response as String.
415         * @return the response
416         * @throws IOException if any I/O error occurs
417         */
418        public final synchronized String fetchContent() throws IOException {
419            if (responseData == null) {
420                try (Scanner scanner = new Scanner(getContentReader()).useDelimiter("\\A")) { // \A - beginning of input
421                    responseData = scanner.hasNext() ? scanner.next() : "";
422                }
423            }
424            return responseData;
425        }
426
427        /**
428         * Gets the response code from this HTTP connection.
429         * @return HTTP response code
430         *
431         * @see HttpURLConnection#getResponseCode()
432         */
433        public final int getResponseCode() {
434            return responseCode;
435        }
436
437        /**
438         * Gets the response message from this HTTP connection.
439         * @return HTTP response message
440         *
441         * @see HttpURLConnection#getResponseMessage()
442         * @since 9172
443         */
444        public final String getResponseMessage() {
445            return responseMessage;
446        }
447
448        /**
449         * Returns the {@code Content-Encoding} header.
450         * @return {@code Content-Encoding} HTTP header
451         * @see HttpURLConnection#getContentEncoding()
452         */
453        public abstract String getContentEncoding();
454
455        /**
456         * Returns the {@code Content-Type} header.
457         * @return {@code Content-Type} HTTP header
458         * @see HttpURLConnection#getContentType()
459         */
460        public abstract String getContentType();
461
462        /**
463         * Returns the {@code Expire} header.
464         * @return {@code Expire} HTTP header
465         * @see HttpURLConnection#getExpiration()
466         * @since 9232
467         */
468        public abstract long getExpiration();
469
470        /**
471         * Returns the {@code Last-Modified} header.
472         * @return {@code Last-Modified} HTTP header
473         * @see HttpURLConnection#getLastModified()
474         * @since 9232
475         */
476        public abstract long getLastModified();
477
478        /**
479         * Returns the {@code Content-Length} header.
480         * @return {@code Content-Length} HTTP header
481         * @see HttpURLConnection#getContentLengthLong()
482         */
483        public abstract long getContentLength();
484
485        /**
486         * Returns the value of the named header field.
487         * @param name the name of a header field
488         * @return the value of the named header field, or {@code null} if there is no such field in the header
489         * @see HttpURLConnection#getHeaderField(String)
490         * @since 9172
491         */
492        public abstract String getHeaderField(String name);
493
494        /**
495         * Returns an unmodifiable Map mapping header keys to a List of header values.
496         * As per RFC 2616, section 4.2 header names are case insensitive, so returned map is also case insensitive
497         * @return unmodifiable Map mapping header keys to a List of header values
498         * @see HttpURLConnection#getHeaderFields()
499         * @since 9232
500         */
501        public abstract Map<String, List<String>> getHeaderFields();
502
503        /**
504         * @see HttpURLConnection#disconnect()
505         */
506        public abstract void disconnect();
507    }
508
509    /**
510     * Creates a new instance for the given URL and a {@code GET} request
511     *
512     * @param url the URL
513     * @return a new instance
514     */
515    public static HttpClient create(URL url) {
516        return create(url, "GET");
517    }
518
519    /**
520     * Creates a new instance for the given URL and a {@code GET} request
521     *
522     * @param url the URL
523     * @param requestMethod the HTTP request method to perform when calling
524     * @return a new instance
525     */
526    public static HttpClient create(URL url, String requestMethod) {
527        return factory.create(url, requestMethod);
528    }
529
530    /**
531     * Returns the URL set for this connection.
532     * @return the URL
533     * @see #create(URL)
534     * @see #create(URL, String)
535     * @since 9172
536     */
537    public final URL getURL() {
538        return url;
539    }
540
541    /**
542     * Returns the request body set for this connection.
543     * @return the HTTP request body, or null
544     * @since 15229
545     */
546    public final byte[] getRequestBody() {
547        return Utils.copyArray(requestBody);
548    }
549
550    /**
551     * Determines if a non-empty request body has been set for this connection.
552     * @return {@code true} if the request body is set and non-empty
553     * @since 15229
554     */
555    public final boolean hasRequestBody() {
556        return requestBody != null && requestBody.length > 0;
557    }
558
559    /**
560     * Determines if the underlying HTTP method requires a body.
561     * @return {@code true} if the underlying HTTP method requires a body
562     * @since 15229
563     */
564    public final boolean requiresBody() {
565        return "PUT".equals(requestMethod) || "POST".equals(requestMethod) || "DELETE".equals(requestMethod);
566    }
567
568    /**
569     * Returns the request method set for this connection.
570     * @return the HTTP request method
571     * @see #create(URL, String)
572     * @since 9172
573     */
574    public final String getRequestMethod() {
575        return requestMethod;
576    }
577
578    /**
579     * Returns the set value for the given {@code header}.
580     * @param header HTTP header name
581     * @return HTTP header value
582     * @since 9172
583     */
584    public final String getRequestHeader(String header) {
585        return headers.get(header);
586    }
587
588    /**
589     * Returns the connect timeout.
590     * @return the connect timeout, in milliseconds
591     * @since 15229
592     */
593    public final int getConnectTimeout() {
594        return connectTimeout;
595    }
596
597    /**
598     * Returns the read timeout.
599     * @return the read timeout, in milliseconds
600     * @since 15229
601     */
602    public final int getReadTimeout() {
603        return readTimeout;
604    }
605
606    /**
607     * Returns the {@code If-Modified-Since} header value.
608     * @return the {@code If-Modified-Since} header value
609     * @since 15229
610     */
611    public final long getIfModifiedSince() {
612        return ifModifiedSince;
613    }
614
615    /**
616     * Determines whether not to set header {@code Cache-Control=no-cache}
617     * @return whether not to set header {@code Cache-Control=no-cache}
618     * @since 15229
619     */
620    public final boolean isUseCache() {
621        return useCache;
622    }
623
624    /**
625     * Returns the headers.
626     * @return the headers
627     * @since 15229
628     */
629    public final Map<String, String> getHeaders() {
630        return headers;
631    }
632
633    /**
634     * Returns the reason for request.
635     * @return the reason for request
636     * @since 15229
637     */
638    public final String getReasonForRequest() {
639        return reasonForRequest;
640    }
641
642    /**
643     * Returns the output message.
644     * @return the output message
645     */
646    protected final String getOutputMessage() {
647        return outputMessage;
648    }
649
650    /**
651     * Determines whether the progress monitor task will be finished when the output stream is closed. {@code true} by default.
652     * @return the finishOnCloseOutput
653     */
654    protected final boolean isFinishOnCloseOutput() {
655        return finishOnCloseOutput;
656    }
657
658    /**
659     * Sets whether not to set header {@code Cache-Control=no-cache}
660     *
661     * @param useCache whether not to set header {@code Cache-Control=no-cache}
662     * @return {@code this}
663     * @see HttpURLConnection#setUseCaches(boolean)
664     */
665    public final HttpClient useCache(boolean useCache) {
666        this.useCache = useCache;
667        return this;
668    }
669
670    /**
671     * Sets whether not to set header {@code Connection=close}
672     * <p>
673     * This might fix #7640, see
674     * <a href='https://web.archive.org/web/20140118201501/http://www.tikalk.com/java/forums/httpurlconnection-disable-keep-alive'>here</a>.
675     *
676     * @param keepAlive whether not to set header {@code Connection=close}
677     * @return {@code this}
678     */
679    public final HttpClient keepAlive(boolean keepAlive) {
680        return setHeader("Connection", keepAlive ? null : "close");
681    }
682
683    /**
684     * Sets a specified timeout value, in milliseconds, to be used when opening a communications link to the resource referenced
685     * by this URLConnection. If the timeout expires before the connection can be established, a
686     * {@link java.net.SocketTimeoutException} is raised. A timeout of zero is interpreted as an infinite timeout.
687     * @param connectTimeout an {@code int} that specifies the connect timeout value in milliseconds
688     * @return {@code this}
689     * @see HttpURLConnection#setConnectTimeout(int)
690     */
691    public final HttpClient setConnectTimeout(int connectTimeout) {
692        this.connectTimeout = connectTimeout;
693        return this;
694    }
695
696    /**
697     * Sets the read timeout to a specified timeout, in milliseconds. A non-zero value specifies the timeout when reading from
698     * input stream when a connection is established to a resource. If the timeout expires before there is data available for
699     * read, a {@link java.net.SocketTimeoutException} is raised. A timeout of zero is interpreted as an infinite timeout.
700     * @param readTimeout an {@code int} that specifies the read timeout value in milliseconds
701     * @return {@code this}
702     * @see HttpURLConnection#setReadTimeout(int)
703     */
704    public final HttpClient setReadTimeout(int readTimeout) {
705        this.readTimeout = readTimeout;
706        return this;
707    }
708
709    /**
710     * Sets the {@code Accept} header.
711     * @param accept header value
712     *
713     * @return {@code this}
714     */
715    public final HttpClient setAccept(String accept) {
716        return setHeader("Accept", accept);
717    }
718
719    /**
720     * Sets the request body for {@code PUT}/{@code POST} requests.
721     * @param requestBody request body
722     *
723     * @return {@code this}
724     */
725    public final HttpClient setRequestBody(byte[] requestBody) {
726        this.requestBody = Utils.copyArray(requestBody);
727        return this;
728    }
729
730    /**
731     * Sets the {@code If-Modified-Since} header.
732     * @param ifModifiedSince header value
733     *
734     * @return {@code this}
735     */
736    public final HttpClient setIfModifiedSince(long ifModifiedSince) {
737        this.ifModifiedSince = ifModifiedSince;
738        return this;
739    }
740
741    /**
742     * Sets the maximum number of redirections to follow.
743     *
744     * Set {@code maxRedirects} to {@code -1} in order to ignore redirects, i.e.,
745     * to not throw an {@link IOException} in {@link #connect()}.
746     * @param maxRedirects header value
747     *
748     * @return {@code this}
749     */
750    public final HttpClient setMaxRedirects(int maxRedirects) {
751        this.maxRedirects = maxRedirects;
752        return this;
753    }
754
755    /**
756     * Sets an arbitrary HTTP header.
757     * @param key header name
758     * @param value header value
759     *
760     * @return {@code this}
761     */
762    public final HttpClient setHeader(String key, String value) {
763        this.headers.put(key, value);
764        return this;
765    }
766
767    /**
768     * Sets arbitrary HTTP headers.
769     * @param headers HTTP headers
770     *
771     * @return {@code this}
772     */
773    public final HttpClient setHeaders(Map<String, String> headers) {
774        this.headers.putAll(headers);
775        return this;
776    }
777
778    /**
779     * Sets a reason to show on console. Can be {@code null} if no reason is given.
780     * @param reasonForRequest Reason to show
781     * @return {@code this}
782     * @since 9172
783     */
784    public final HttpClient setReasonForRequest(String reasonForRequest) {
785        this.reasonForRequest = reasonForRequest;
786        return this;
787    }
788
789    /**
790     * Sets the output message to be displayed in progress monitor for {@code PUT}, {@code POST} and {@code DELETE} methods.
791     * Defaults to "Uploading data ..." (translated). Has no effect for {@code GET} or any other method.
792     * @param outputMessage message to be displayed in progress monitor
793     * @return {@code this}
794     * @since 12711
795     */
796    public final HttpClient setOutputMessage(String outputMessage) {
797        this.outputMessage = outputMessage;
798        return this;
799    }
800
801    /**
802     * Sets whether the progress monitor task will be finished when the output stream is closed. This is {@code true} by default.
803     * @param finishOnCloseOutput whether the progress monitor task will be finished when the output stream is closed
804     * @return {@code this}
805     * @since 10302
806     */
807    public final HttpClient setFinishOnCloseOutput(boolean finishOnCloseOutput) {
808        this.finishOnCloseOutput = finishOnCloseOutput;
809        return this;
810    }
811
812    /**
813     * Sets the connect log at DEBUG level instead of the default INFO level.
814     * @param debug {@code true} to set the connect log at DEBUG level
815     * @return {@code this}
816     * @since 15389
817     */
818    public final HttpClient setLogAtDebug(boolean debug) {
819        this.debug = debug;
820        return this;
821    }
822
823    /**
824     * Determines if the given status code is an HTTP redirection.
825     * @param statusCode HTTP status code
826     * @return {@code true} if the given status code is an HTTP redirection
827     * @since 15423
828     */
829    public static boolean isRedirect(final int statusCode) {
830        switch (statusCode) {
831            case HttpURLConnection.HTTP_MOVED_PERM: // 301
832            case HttpURLConnection.HTTP_MOVED_TEMP: // 302
833            case HttpURLConnection.HTTP_SEE_OTHER: // 303
834            case 307: // TEMPORARY_REDIRECT:
835            case 308: // PERMANENT_REDIRECT:
836                return true;
837            default:
838                return false;
839        }
840    }
841
842    /**
843     * Disconnect client.
844     * @see HttpURLConnection#disconnect()
845     * @since 9309
846     */
847    public abstract void disconnect();
848
849    /**
850     * Returns a {@link Matcher} against predefined Tomcat error messages.
851     * If it matches, error message can be extracted from {@code group(1)}.
852     * @param data HTML contents to check
853     * @return a {@link Matcher} against predefined Tomcat error messages
854     * @since 13358
855     */
856    public static Matcher getTomcatErrorMatcher(String data) {
857        return data != null ? TOMCAT_ERR_MESSAGE.matcher(data) : null;
858    }
859}