UrlValidator.java
/*
* 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
*
* https://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>
* Behaviour 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,
* https://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>
*
* @since 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 int TOP_LEVEL_MAX_LEN = 4;
private static final int TOP_LEVEL_MIN_LEN = 2;
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 = ";/@&=,.?:+$";
private static final String VALID_CHARS = "[^\\s" + SPECIAL_CHARS + "]";
// Drop numeric, and "+-." for now
private static final String AUTHORITY_CHARS_REGEX = "\\p{Alnum}\\-\\.";
private static final String ATOM = VALID_CHARS + '+';
/**
* This expression derived/taken from the BNF for URI (RFC2396).
*/
private static final String URL_REGEX =
"^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\\?([^#]*))?(#(.*))?";
// 12 3 4 5 6 7 8 9
private static final Pattern URL_PATTERN = Pattern.compile(URL_REGEX);
/**
* Schema/Protocol (ie. http:, ftp:, file:, etc).
*/
private static final int PARSE_URL_SCHEME = 2;
/**
* Includes hostname/ip and port number.
*/
private static final int PARSE_URL_AUTHORITY = 4;
private static final int PARSE_URL_PATH = 5;
private static final int PARSE_URL_QUERY = 7;
private static final int PARSE_URL_FRAGMENT = 9;
/**
* Protocol (for example, http:, ftp:, https:).
*/
private static final Pattern SCHEME_PATTERN = Pattern.compile("^\\p{Alpha}[\\p{Alnum}\\+\\-\\.]*");
private static final String AUTHORITY_REGEX =
"^([" + AUTHORITY_CHARS_REGEX + "]*)(:\\d*)?(.*)?";
// 1 2 3 4
private static final Pattern AUTHORITY_PATTERN = Pattern.compile(AUTHORITY_REGEX);
private static final int PARSE_AUTHORITY_HOST_IP = 1;
private static final int PARSE_AUTHORITY_PORT = 2;
/**
* Should always be empty.
*/
private static final int PARSE_AUTHORITY_EXTRA = 3;
private static final Pattern PATH_PATTERN = Pattern.compile("^(/[-\\w:@&?=+,.!/~*'%$_;]*)?$");
private static final Pattern QUERY_PATTERN = Pattern.compile("^(.*)$");
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<>();
/**
* 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);
}
/**
* 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(final int options) {
this(null, options);
}
/**
* 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(final String[] schemes) {
this(schemes, 0);
}
/**
* Behaviour 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, final int options) {
this.options = new Flags(options);
if (this.options.isOn(ALLOW_ALL_SCHEMES)) {
return;
}
if (schemes == null) {
schemes = defaultSchemes;
}
allowedSchemes.addAll(Arrays.asList(schemes));
}
/**
* 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(final String token, final String target) {
int tokenIndex = 0;
int count = 0;
while (tokenIndex != -1) {
tokenIndex = target.indexOf(token, tokenIndex);
if (tokenIndex > -1) {
tokenIndex++;
count++;
}
}
return count;
}
/**
* <p>Checks if a field has a valid URL address.</p>
*
* @param value The value validation is being performed on. A {@code null}
* value is considered invalid.
* @return true if the URL is valid.
*/
public boolean isValid(final String value) {
if (value == null || !LEGAL_ASCII_PATTERN.matcher(value).matches()) {
return false;
}
// Check the whole url address structure
final Matcher urlMatcher = URL_PATTERN.matcher(value);
if (!urlMatcher.matches() || !isValidScheme(urlMatcher.group(PARSE_URL_SCHEME)) || !isValidAuthority(urlMatcher.group(PARSE_URL_AUTHORITY)) || !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;
}
/**
* Returns true if the authority is properly formatted. An authority is the combination
* of hostname and port. A {@code null} authority value is considered invalid.
* @param authority Authority value to validate.
* @return true if authority (hostname and port) is valid.
*/
protected boolean isValidAuthority(final String authority) {
if (authority == null) {
return false;
}
final InetAddressValidator inetAddressValidator =
InetAddressValidator.getInstance();
final 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);
final 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
final char[] chars = hostIP.toCharArray();
int size = 1;
for (final char element : chars) {
if (element == '.') {
size++;
}
}
final String[] domainSegment = new String[size];
boolean match = true;
int segmentCount = 0;
int segmentLength = 0;
while (match) {
final 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++;
}
}
final String topLevel = domainSegment[segmentCount - 1];
// First letter of top level must be an alpha
// Make sure there's a host name preceding the authority.
if (topLevel.length() < TOP_LEVEL_MIN_LEN || topLevel.length() > TOP_LEVEL_MAX_LEN || !ALPHA_PATTERN.matcher(topLevel.substring(0, 1)).matches()
|| segmentCount < 2) {
return false;
}
}
if (!hostname && !ipV4Address) {
return false;
}
final String port = authorityMatcher.group(PARSE_AUTHORITY_PORT);
if (port != null && !PORT_PATTERN.matcher(port).matches()) {
return false;
}
final String extra = authorityMatcher.group(PARSE_AUTHORITY_EXTRA);
if (!GenericValidator.isBlankOrNull(extra)) {
return false;
}
return true;
}
/**
* 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(final String fragment) {
if (fragment == null) {
return true;
}
return options.isOff(NO_FRAGMENTS);
}
/**
* Returns true if the path is valid. A {@code null} value is considered invalid.
* @param path Path value to validate.
* @return true if path is valid.
*/
protected boolean isValidPath(final String path) {
if (path == null || !PATH_PATTERN.matcher(path).matches()) {
return false;
}
final int slash2Count = countToken("//", path);
if (options.isOff(ALLOW_2_SLASHES) && slash2Count > 0) {
return false;
}
final int slashCount = countToken("/", path);
final 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(final String query) {
if (query == null) {
return true;
}
return QUERY_PATTERN.matcher(query).matches();
}
/**
* Validate scheme. If schemes[] was initialized to a non-null,
* then only those schemes are allowed. Note this is slightly different
* than for the constructor.
* @param scheme The scheme to validate. A {@code null} value is considered
* invalid.
* @return true if valid.
*/
protected boolean isValidScheme(final String scheme) {
if (scheme == null || !SCHEME_PATTERN.matcher(scheme).matches() || options.isOff(ALLOW_ALL_SCHEMES) && !allowedSchemes.contains(scheme)) {
return false;
}
return true;
}
}