Source code

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 */
017package org.apache.commons.validator;
018
019import java.io.Serializable;
020import java.util.Arrays;
021import java.util.HashSet;
022import java.util.Set;
023import java.util.regex.Matcher;
024import java.util.regex.Pattern;
025
026import org.apache.commons.validator.routines.InetAddressValidator;
027import org.apache.commons.validator.util.Flags;
028
029/**
030 * <p>Validates URLs.</p>
031 * Behavour of validation is modified by passing in options:
032 * <ul>
033 * <li>ALLOW_2_SLASHES - [FALSE]  Allows double '/' characters in the path
034 * component.</li>
035 * <li>NO_FRAGMENT- [FALSE]  By default fragments are allowed, if this option is
036 * included then fragments are flagged as illegal.</li>
037 * <li>ALLOW_ALL_SCHEMES - [FALSE] By default only http, https, and ftp are
038 * considered valid schemes.  Enabling this option will let any scheme pass validation.</li>
039 * </ul>
040 *
041 * <p>Originally based in on php script by Debbie Dyer, validation.php v1.2b, Date: 03/07/02,
042 * http://javascript.internet.com. However, this validation now bears little resemblance
043 * to the php original.</p>
044 * <pre>
045 *   Example of usage:
046 *   Construct a UrlValidator with valid schemes of "http", and "https".
047 *
048 *    String[] schemes = {"http","https"}.
049 *    UrlValidator urlValidator = new UrlValidator(schemes);
050 *    if (urlValidator.isValid("ftp://foo.bar.com/")) {
051 *       System.out.println("URL is valid");
052 *    } else {
053 *       System.out.println("URL is invalid");
054 *    }
055 *
056 *    prints "URL is invalid"
057 *   If instead the default constructor is used.
058 *
059 *    UrlValidator urlValidator = new UrlValidator();
060 *    if (urlValidator.isValid("ftp://foo.bar.com/")) {
061 *       System.out.println("URL is valid");
062 *    } else {
063 *       System.out.println("URL is invalid");
064 *    }
065 *
066 *   prints out "URL is valid"
067 *  </pre>
068 *
069 * @see
070 * <a href="http://www.ietf.org/rfc/rfc2396.txt">
071 *  Uniform Resource Identifiers (URI): Generic Syntax
072 * </a>
073 *
074 * @since 1.1
075 * @deprecated Use the new UrlValidator in the routines package. This class
076 * will be removed in a future release.
077 */
078@Deprecated
079public class UrlValidator implements Serializable {
080
081    private static final long serialVersionUID = 24137157400029593L;
082
083    /**
084     * Allows all validly formatted schemes to pass validation instead of
085     * supplying a set of valid schemes.
086     */
087    public static final int ALLOW_ALL_SCHEMES = 1 << 0;
088
089    /**
090     * Allow two slashes in the path component of the URL.
091     */
092    public static final int ALLOW_2_SLASHES = 1 << 1;
093
094    /**
095     * Enabling this options disallows any URL fragments.
096     */
097    public static final int NO_FRAGMENTS = 1 << 2;
098
099    private static final String ALPHA_CHARS = "a-zA-Z";
100
101// NOT USED   private static final String ALPHA_NUMERIC_CHARS = ALPHA_CHARS + "\\d";
102
103    private static final String SPECIAL_CHARS = ";/@&=,.?:+$";
104
105    private static final String VALID_CHARS = "[^\\s" + SPECIAL_CHARS + "]";
106
107    // Drop numeric, and  "+-." for now
108    private static final String AUTHORITY_CHARS_REGEX = "\\p{Alnum}\\-\\.";
109
110    private static final String ATOM = VALID_CHARS + '+';
111
112    /**
113     * This expression derived/taken from the BNF for URI (RFC2396).
114     */
115    private static final String URL_REGEX =
116            "^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\\?([^#]*))?(#(.*))?";
117    //                                                                      12            3  4          5       6   7        8 9
118    private static final Pattern URL_PATTERN = Pattern.compile(URL_REGEX);
119
120    /**
121     * Schema/Protocol (ie. http:, ftp:, file:, etc).
122     */
123    private static final int PARSE_URL_SCHEME = 2;
124
125    /**
126     * Includes hostname/ip and port number.
127     */
128    private static final int PARSE_URL_AUTHORITY = 4;
129
130    private static final int PARSE_URL_PATH = 5;
131
132    private static final int PARSE_URL_QUERY = 7;
133
134    private static final int PARSE_URL_FRAGMENT = 9;
135
136    /**
137     * Protocol (ie. http:, ftp:,https:).
138     */
139    private static final Pattern SCHEME_PATTERN = Pattern.compile("^\\p{Alpha}[\\p{Alnum}\\+\\-\\.]*");
140
141    private static final String AUTHORITY_REGEX =
142       "^([" + AUTHORITY_CHARS_REGEX + "]*)(:\\d*)?(.*)?";
143    //                                                                            1                          2  3       4
144    private static final Pattern AUTHORITY_PATTERN = Pattern.compile(AUTHORITY_REGEX);
145
146    private static final int PARSE_AUTHORITY_HOST_IP = 1;
147
148    private static final int PARSE_AUTHORITY_PORT = 2;
149
150    /**
151     * Should always be empty.
152     */
153    private static final int PARSE_AUTHORITY_EXTRA = 3;
154
155    private static final Pattern PATH_PATTERN = Pattern.compile("^(/[-\\w:@&?=+,.!/~*'%$_;]*)?$");
156
157    private static final Pattern QUERY_PATTERN = Pattern.compile("^(.*)$");
158
159    private static final Pattern LEGAL_ASCII_PATTERN = Pattern.compile("^\\p{ASCII}+$");
160
161    private static final Pattern DOMAIN_PATTERN =
162            Pattern.compile("^" + ATOM + "(\\." + ATOM + ")*$");
163
164    private static final Pattern PORT_PATTERN = Pattern.compile("^:(\\d{1,5})$");
165
166    private static final Pattern ATOM_PATTERN = Pattern.compile("^(" + ATOM + ").*?$");
167
168    private static final Pattern ALPHA_PATTERN = Pattern.compile("^[" + ALPHA_CHARS + "]");
169
170    /**
171     * Holds the set of current validation options.
172     */
173    private final Flags options;
174
175    /**
176     * The set of schemes that are allowed to be in a URL.
177     */
178    private final Set<String> allowedSchemes = new HashSet<>();
179
180    /**
181     * If no schemes are provided, default to this set.
182     */
183    protected String[] defaultSchemes = {"http", "https", "ftp"};
184
185    /**
186     * Create a UrlValidator with default properties.
187     */
188    public UrlValidator() {
189        this(null);
190    }
191
192    /**
193     * Initialize a UrlValidator with the given validation options.
194     * @param options The options should be set using the public constants declared in
195     * this class.  To set multiple options you simply add them together.  For example,
196     * ALLOW_2_SLASHES + NO_FRAGMENTS enables both of those options.
197     */
198    public UrlValidator(final int options) {
199        this(null, options);
200    }
201
202    /**
203     * Behavior of validation is modified by passing in several strings options:
204     * @param schemes Pass in one or more URL schemes to consider valid, passing in
205     *        a null will default to "http,https,ftp" being valid.
206     *        If a non-null schemes is specified then all valid schemes must
207     *        be specified. Setting the ALLOW_ALL_SCHEMES option will
208     *        ignore the contents of schemes.
209     */
210    public UrlValidator(final String[] schemes) {
211        this(schemes, 0);
212    }
213
214    /**
215     * Behavour of validation is modified by passing in options:
216     * @param schemes The set of valid schemes.
217     * @param options The options should be set using the public constants declared in
218     * this class.  To set multiple options you simply add them together.  For example,
219     * ALLOW_2_SLASHES + NO_FRAGMENTS enables both of those options.
220     */
221    public UrlValidator(String[] schemes, final int options) {
222        this.options = new Flags(options);
223
224        if (this.options.isOn(ALLOW_ALL_SCHEMES)) {
225            return;
226        }
227
228        if (schemes == null) {
229            schemes = this.defaultSchemes;
230        }
231
232        this.allowedSchemes.addAll(Arrays.asList(schemes));
233    }
234
235    /**
236     * Returns the number of times the token appears in the target.
237     * @param token Token value to be counted.
238     * @param target Target value to count tokens in.
239     * @return the number of tokens.
240     */
241    protected int countToken(final String token, final String target) {
242        int tokenIndex = 0;
243        int count = 0;
244        while (tokenIndex != -1) {
245            tokenIndex = target.indexOf(token, tokenIndex);
246            if (tokenIndex > -1) {
247                tokenIndex++;
248                count++;
249            }
250        }
251        return count;
252    }
253
254    /**
255     * <p>Checks if a field has a valid URL address.</p>
256     *
257     * @param value The value validation is being performed on.  A <code>null</code>
258     * value is considered invalid.
259     * @return true if the URL is valid.
260     */
261    public boolean isValid(final String value) {
262        if (value == null) {
263            return false;
264        }
265        if (!LEGAL_ASCII_PATTERN.matcher(value).matches()) {
266           return false;
267        }
268
269        // Check the whole url address structure
270        final Matcher urlMatcher = URL_PATTERN.matcher(value);
271        if (!urlMatcher.matches()) {
272            return false;
273        }
274
275        if (!isValidScheme(urlMatcher.group(PARSE_URL_SCHEME))) {
276            return false;
277        }
278
279        if (!isValidAuthority(urlMatcher.group(PARSE_URL_AUTHORITY))) {
280            return false;
281        }
282
283        if (!isValidPath(urlMatcher.group(PARSE_URL_PATH))) {
284            return false;
285        }
286
287        if (!isValidQuery(urlMatcher.group(PARSE_URL_QUERY))) {
288            return false;
289        }
290
291        if (!isValidFragment(urlMatcher.group(PARSE_URL_FRAGMENT))) {
292            return false;
293        }
294
295        return true;
296    }
297
298    /**
299     * Returns true if the authority is properly formatted.  An authority is the combination
300     * of hostname and port.  A <code>null</code> authority value is considered invalid.
301     * @param authority Authority value to validate.
302     * @return true if authority (hostname and port) is valid.
303     */
304    protected boolean isValidAuthority(final String authority) {
305        if (authority == null) {
306            return false;
307        }
308
309        final InetAddressValidator inetAddressValidator =
310                InetAddressValidator.getInstance();
311
312        final Matcher authorityMatcher = AUTHORITY_PATTERN.matcher(authority);
313        if (!authorityMatcher.matches()) {
314            return false;
315        }
316
317        boolean hostname = false;
318        // check if authority is IP address or hostname
319        String hostIP = authorityMatcher.group(PARSE_AUTHORITY_HOST_IP);
320        final boolean ipV4Address = inetAddressValidator.isValid(hostIP);
321
322        if (!ipV4Address) {
323            // Domain is hostname name
324            hostname = DOMAIN_PATTERN.matcher(hostIP).matches();
325        }
326
327        //rightmost hostname will never start with a digit.
328        if (hostname) {
329            // LOW-TECH FIX FOR VALIDATOR-202
330            // TODO: Rewrite to use ArrayList and .add semantics: see VALIDATOR-203
331            final char[] chars = hostIP.toCharArray();
332            int size = 1;
333            for (final char element : chars) {
334                if (element == '.') {
335                    size++;
336                }
337            }
338            final String[] domainSegment = new String[size];
339            boolean match = true;
340            int segmentCount = 0;
341            int segmentLength = 0;
342
343            while (match) {
344                final Matcher atomMatcher = ATOM_PATTERN.matcher(hostIP);
345                match = atomMatcher.matches();
346                if (match) {
347                    domainSegment[segmentCount] = atomMatcher.group(1);
348                    segmentLength = domainSegment[segmentCount].length() + 1;
349                    hostIP =
350                            segmentLength >= hostIP.length()
351                            ? ""
352                            : hostIP.substring(segmentLength);
353
354                    segmentCount++;
355                }
356            }
357            final String topLevel = domainSegment[segmentCount - 1];
358            if (topLevel.length() < 2 || topLevel.length() > 4) { // CHECKSTYLE IGNORE MagicNumber (deprecated code)
359                return false;
360            }
361
362            // First letter of top level must be a alpha
363            if (!ALPHA_PATTERN.matcher(topLevel.substring(0, 1)).matches()) {
364                return false;
365            }
366
367            // Make sure there's a host name preceding the authority.
368            if (segmentCount < 2) {
369                return false;
370            }
371        }
372
373        if (!hostname && !ipV4Address) {
374            return false;
375        }
376
377        final String port = authorityMatcher.group(PARSE_AUTHORITY_PORT);
378        if (port != null && !PORT_PATTERN.matcher(port).matches()) {
379            return false;
380        }
381
382        final String extra = authorityMatcher.group(PARSE_AUTHORITY_EXTRA);
383        if (!GenericValidator.isBlankOrNull(extra)) {
384            return false;
385        }
386
387        return true;
388    }
389
390    /**
391     * Returns true if the given fragment is null or fragments are allowed.
392     * @param fragment Fragment value to validate.
393     * @return true if fragment is valid.
394     */
395    protected boolean isValidFragment(final String fragment) {
396        if (fragment == null) {
397            return true;
398        }
399
400        return options.isOff(NO_FRAGMENTS);
401    }
402
403    /**
404     * Returns true if the path is valid.  A <code>null</code> value is considered invalid.
405     * @param path Path value to validate.
406     * @return true if path is valid.
407     */
408    protected boolean isValidPath(final String path) {
409        if (path == null) {
410            return false;
411        }
412
413        if (!PATH_PATTERN.matcher(path).matches()) {
414            return false;
415        }
416
417        final int slash2Count = countToken("//", path);
418        if (options.isOff(ALLOW_2_SLASHES) && slash2Count > 0) {
419            return false;
420        }
421
422        final int slashCount = countToken("/", path);
423        final int dot2Count = countToken("..", path);
424        if (dot2Count > 0 && slashCount - slash2Count - 1 <= dot2Count) {
425            return false;
426        }
427
428        return true;
429    }
430
431    /**
432     * Returns true if the query is null or it's a properly formatted query string.
433     * @param query Query value to validate.
434     * @return true if query is valid.
435     */
436    protected boolean isValidQuery(final String query) {
437        if (query == null) {
438            return true;
439        }
440
441        return QUERY_PATTERN.matcher(query).matches();
442    }
443
444    /**
445     * Validate scheme. If schemes[] was initialized to a non null,
446     * then only those scheme's are allowed.  Note this is slightly different
447     * than for the constructor.
448     * @param scheme The scheme to validate.  A <code>null</code> value is considered
449     * invalid.
450     * @return true if valid.
451     */
452    protected boolean isValidScheme(final String scheme) {
453        if (scheme == null) {
454            return false;
455        }
456
457        if (!SCHEME_PATTERN.matcher(scheme).matches()) {
458            return false;
459        }
460
461        if (options.isOff(ALLOW_ALL_SCHEMES) && !allowedSchemes.contains(scheme)) {
462            return false;
463        }
464
465        return true;
466    }
467}