Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.validator; import java.io.Serializable; import java.util.Arrays; import java.util.HashSet; import java.util.Set; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.validator.routines.InetAddressValidator; import org.apache.commons.validator.util.Flags; /** * <p>Validates URLs.</p> * Behavour of validation is modified by passing in options: * <ul> * <li>ALLOW_2_SLASHES - [FALSE] Allows double '/' characters in the path * component.</li> * <li>NO_FRAGMENT- [FALSE] By default fragments are allowed, if this option is * included then fragments are flagged as illegal.</li> * <li>ALLOW_ALL_SCHEMES - [FALSE] By default only http, https, and ftp are * considered valid schemes. Enabling this option will let any scheme pass validation.</li> * </ul> * * <p>Originally based in on php script by Debbie Dyer, validation.php v1.2b, Date: 03/07/02, * http://javascript.internet.com. However, this validation now bears little resemblance * to the php original.</p> * <pre> * Example of usage: * Construct a UrlValidator with valid schemes of "http", and "https". * * String[] schemes = {"http","https"}. * UrlValidator urlValidator = new UrlValidator(schemes); * if (urlValidator.isValid("ftp://foo.bar.com/")) { * System.out.println("url is valid"); * } else { * System.out.println("url is invalid"); * } * * prints "url is invalid" * If instead the default constructor is used. * * UrlValidator urlValidator = new UrlValidator(); * if (urlValidator.isValid("ftp://foo.bar.com/")) { * System.out.println("url is valid"); * } else { * System.out.println("url is invalid"); * } * * prints out "url is valid" * </pre> * * @see * <a href="http://www.ietf.org/rfc/rfc2396.txt"> * Uniform Resource Identifiers (URI): Generic Syntax * </a> * * @version $Revision: 1739358 $ * @since Validator 1.1 * @deprecated Use the new UrlValidator in the routines package. This class * will be removed in a future release. */ @Deprecated public class UrlValidator implements Serializable { private static final long serialVersionUID = 24137157400029593L; /** * Allows all validly formatted schemes to pass validation instead of * supplying a set of valid schemes. */ public static final int ALLOW_ALL_SCHEMES = 1 << 0; /** * Allow two slashes in the path component of the URL. */ public static final int ALLOW_2_SLASHES = 1 << 1; /** * Enabling this options disallows any URL fragments. */ public static final int NO_FRAGMENTS = 1 << 2; private static final String ALPHA_CHARS = "a-zA-Z"; // NOT USED private static final String ALPHA_NUMERIC_CHARS = ALPHA_CHARS + "\\d"; private static final String SPECIAL_CHARS = ";/@&=,.?:+$"; private static final String VALID_CHARS = "[^\\s" + SPECIAL_CHARS + "]"; // Drop numeric, and "+-." for now private static final String AUTHORITY_CHARS_REGEX = "\\p{Alnum}\\-\\."; private static final String ATOM = VALID_CHARS + '+'; /** * This expression derived/taken from the BNF for URI (RFC2396). */ private static final String URL_REGEX = "^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\\?([^#]*))?(#(.*))?"; // 12 3 4 5 6 7 8 9 private static final Pattern URL_PATTERN = Pattern.compile(URL_REGEX); /** * Schema/Protocol (ie. http:, ftp:, file:, etc). */ private static final int PARSE_URL_SCHEME = 2; /** * Includes hostname/ip and port number. */ private static final int PARSE_URL_AUTHORITY = 4; private static final int PARSE_URL_PATH = 5; private static final int PARSE_URL_QUERY = 7; private static final int PARSE_URL_FRAGMENT = 9; /** * Protocol (ie. http:, ftp:,https:). */ private static final Pattern SCHEME_PATTERN = Pattern.compile("^\\p{Alpha}[\\p{Alnum}\\+\\-\\.]*"); private static final String AUTHORITY_REGEX = "^([" + AUTHORITY_CHARS_REGEX + "]*)(:\\d*)?(.*)?"; // 1 2 3 4 private static final Pattern AUTHORITY_PATTERN = Pattern.compile(AUTHORITY_REGEX); private static final int PARSE_AUTHORITY_HOST_IP = 1; private static final int PARSE_AUTHORITY_PORT = 2; /** * Should always be empty. */ private static final int PARSE_AUTHORITY_EXTRA = 3; private static final Pattern PATH_PATTERN = Pattern.compile("^(/[-\\w:@&?=+,.!/~*'%$_;]*)?$"); private static final Pattern QUERY_PATTERN = Pattern.compile("^(.*)$"); private static final Pattern LEGAL_ASCII_PATTERN = Pattern.compile("^\\p{ASCII}+$"); private static final Pattern DOMAIN_PATTERN = Pattern.compile("^" + ATOM + "(\\." + ATOM + ")*$"); private static final Pattern PORT_PATTERN = Pattern.compile("^:(\\d{1,5})$"); private static final Pattern ATOM_PATTERN = Pattern.compile("^(" + ATOM + ").*?$"); private static final Pattern ALPHA_PATTERN = Pattern.compile("^[" + ALPHA_CHARS + "]"); /** * Holds the set of current validation options. */ private final Flags options; /** * The set of schemes that are allowed to be in a URL. */ private final Set<String> allowedSchemes = new HashSet<String>(); /** * If no schemes are provided, default to this set. */ protected String[] defaultSchemes = { "http", "https", "ftp" }; /** * Create a UrlValidator with default properties. */ public UrlValidator() { this(null); } /** * Behavior of validation is modified by passing in several strings options: * @param schemes Pass in one or more url schemes to consider valid, passing in * a null will default to "http,https,ftp" being valid. * If a non-null schemes is specified then all valid schemes must * be specified. Setting the ALLOW_ALL_SCHEMES option will * ignore the contents of schemes. */ public UrlValidator(String[] schemes) { this(schemes, 0); } /** * Initialize a UrlValidator with the given validation options. * @param options The options should be set using the public constants declared in * this class. To set multiple options you simply add them together. For example, * ALLOW_2_SLASHES + NO_FRAGMENTS enables both of those options. */ public UrlValidator(int options) { this(null, options); } /** * Behavour of validation is modified by passing in options: * @param schemes The set of valid schemes. * @param options The options should be set using the public constants declared in * this class. To set multiple options you simply add them together. For example, * ALLOW_2_SLASHES + NO_FRAGMENTS enables both of those options. */ public UrlValidator(String[] schemes, int options) { this.options = new Flags(options); if (this.options.isOn(ALLOW_ALL_SCHEMES)) { return; } if (schemes == null) { schemes = this.defaultSchemes; } this.allowedSchemes.addAll(Arrays.asList(schemes)); } /** * <p>Checks if a field has a valid url address.</p> * * @param value The value validation is being performed on. A <code>null</code> * value is considered invalid. * @return true if the url is valid. */ public boolean isValid(String value) { if (value == null) { return false; } if (!LEGAL_ASCII_PATTERN.matcher(value).matches()) { return false; } // Check the whole url address structure Matcher urlMatcher = URL_PATTERN.matcher(value); if (!urlMatcher.matches()) { return false; } if (!isValidScheme(urlMatcher.group(PARSE_URL_SCHEME))) { return false; } if (!isValidAuthority(urlMatcher.group(PARSE_URL_AUTHORITY))) { return false; } if (!isValidPath(urlMatcher.group(PARSE_URL_PATH))) { return false; } if (!isValidQuery(urlMatcher.group(PARSE_URL_QUERY))) { return false; } if (!isValidFragment(urlMatcher.group(PARSE_URL_FRAGMENT))) { return false; } return true; } /** * Validate scheme. If schemes[] was initialized to a non null, * then only those scheme's are allowed. Note this is slightly different * than for the constructor. * @param scheme The scheme to validate. A <code>null</code> value is considered * invalid. * @return true if valid. */ protected boolean isValidScheme(String scheme) { if (scheme == null) { return false; } if (!SCHEME_PATTERN.matcher(scheme).matches()) { return false; } if (options.isOff(ALLOW_ALL_SCHEMES) && !allowedSchemes.contains(scheme)) { return false; } return true; } /** * Returns true if the authority is properly formatted. An authority is the combination * of hostname and port. A <code>null</code> authority value is considered invalid. * @param authority Authority value to validate. * @return true if authority (hostname and port) is valid. */ protected boolean isValidAuthority(String authority) { if (authority == null) { return false; } InetAddressValidator inetAddressValidator = InetAddressValidator.getInstance(); Matcher authorityMatcher = AUTHORITY_PATTERN.matcher(authority); if (!authorityMatcher.matches()) { return false; } boolean hostname = false; // check if authority is IP address or hostname String hostIP = authorityMatcher.group(PARSE_AUTHORITY_HOST_IP); boolean ipV4Address = inetAddressValidator.isValid(hostIP); if (!ipV4Address) { // Domain is hostname name hostname = DOMAIN_PATTERN.matcher(hostIP).matches(); } //rightmost hostname will never start with a digit. if (hostname) { // LOW-TECH FIX FOR VALIDATOR-202 // TODO: Rewrite to use ArrayList and .add semantics: see VALIDATOR-203 char[] chars = hostIP.toCharArray(); int size = 1; for (int i = 0; i < chars.length; i++) { if (chars[i] == '.') { size++; } } String[] domainSegment = new String[size]; boolean match = true; int segmentCount = 0; int segmentLength = 0; while (match) { Matcher atomMatcher = ATOM_PATTERN.matcher(hostIP); match = atomMatcher.matches(); if (match) { domainSegment[segmentCount] = atomMatcher.group(1); segmentLength = domainSegment[segmentCount].length() + 1; hostIP = (segmentLength >= hostIP.length()) ? "" : hostIP.substring(segmentLength); segmentCount++; } } String topLevel = domainSegment[segmentCount - 1]; if (topLevel.length() < 2 || topLevel.length() > 4) { // CHECKSTYLE IGNORE MagicNumber (deprecated code) return false; } // First letter of top level must be a alpha if (!ALPHA_PATTERN.matcher(topLevel.substring(0, 1)).matches()) { return false; } // Make sure there's a host name preceding the authority. if (segmentCount < 2) { return false; } } if (!hostname && !ipV4Address) { return false; } String port = authorityMatcher.group(PARSE_AUTHORITY_PORT); if (port != null && !PORT_PATTERN.matcher(port).matches()) { return false; } String extra = authorityMatcher.group(PARSE_AUTHORITY_EXTRA); if (!GenericValidator.isBlankOrNull(extra)) { return false; } return true; } /** * Returns true if the path is valid. A <code>null</code> value is considered invalid. * @param path Path value to validate. * @return true if path is valid. */ protected boolean isValidPath(String path) { if (path == null) { return false; } if (!PATH_PATTERN.matcher(path).matches()) { return false; } int slash2Count = countToken("//", path); if (options.isOff(ALLOW_2_SLASHES) && (slash2Count > 0)) { return false; } int slashCount = countToken("/", path); int dot2Count = countToken("..", path); if (dot2Count > 0 && (slashCount - slash2Count - 1) <= dot2Count) { return false; } return true; } /** * Returns true if the query is null or it's a properly formatted query string. * @param query Query value to validate. * @return true if query is valid. */ protected boolean isValidQuery(String query) { if (query == null) { return true; } return QUERY_PATTERN.matcher(query).matches(); } /** * Returns true if the given fragment is null or fragments are allowed. * @param fragment Fragment value to validate. * @return true if fragment is valid. */ protected boolean isValidFragment(String fragment) { if (fragment == null) { return true; } return options.isOff(NO_FRAGMENTS); } /** * Returns the number of times the token appears in the target. * @param token Token value to be counted. * @param target Target value to count tokens in. * @return the number of tokens. */ protected int countToken(String token, String target) { int tokenIndex = 0; int count = 0; while (tokenIndex != -1) { tokenIndex = target.indexOf(token, tokenIndex); if (tokenIndex > -1) { tokenIndex++; count++; } } return count; } }