/
UrlValidator.java
491 lines (406 loc) · 15.2 KB
/
UrlValidator.java
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/*
* $Id$
* $Rev$
* $Date$
*
* ====================================================================
* Copyright 2001-2005 The Apache Software Foundation
*
* Licensed 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 org.apache.commons.validator.util.Flags;
import org.apache.oro.text.perl.Perl5Util;
/**
* <p>Validates URLs.</p>
* Behavour of validation is modified by passing in options:
* <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>
*
* <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>
*
* @since Validator 1.1
*/
public class UrlValidator implements Serializable {
/**
* 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";
private static final String ALPHA_NUMERIC_CHARS = ALPHA_CHARS + "\\d";
private static final String SPECIAL_CHARS = ";/@&=,.?:+$";
private static final String VALID_CHARS = "[^\\s" + SPECIAL_CHARS + "]";
private static final String SCHEME_CHARS = ALPHA_CHARS;
// Drop numeric, and "+-." for now
private static final String AUTHORITY_CHARS = ALPHA_NUMERIC_CHARS + "\\-\\.";
private static final String ATOM = VALID_CHARS + '+';
/**
* This expression derived/taken from the BNF for URI (RFC2396).
*/
private static final String URL_PATTERN =
"/^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\\?([^#]*))?(#(.*))?/";
// 12 3 4 5 6 7 8 9
/**
* Schema/Protocol (ie. http:, ftp:, file:, etc).
*/
private static final int PARSE_URL_SCHEME = 2;
/**
* Includes hostname/ip and port number.
*/
private static final int PARSE_URL_AUTHORITY = 4;
private static final int PARSE_URL_PATH = 5;
private static final int PARSE_URL_QUERY = 7;
private static final int PARSE_URL_FRAGMENT = 9;
/**
* Protocol (ie. http:, ftp:,https:).
*/
private static final String SCHEME_PATTERN = "/^[" + SCHEME_CHARS + "]/";
private static final String AUTHORITY_PATTERN =
"/^([" + AUTHORITY_CHARS + "]*)(:\\d*)?(.*)?/";
// 1 2 3 4
private static final int PARSE_AUTHORITY_HOST_IP = 1;
private static final int PARSE_AUTHORITY_PORT = 2;
/**
* Should always be empty.
*/
private static final int PARSE_AUTHORITY_EXTRA = 3;
private static final String PATH_PATTERN = "/^(/[-\\w:@&?=+,.!/~*'%$]*)?$/";
private static final String QUERY_PATTERN = "/^(.*)$/";
private static final String LEGAL_ASCII_PATTERN = "/^[\\000-\\177]+$/";
private static final String IP_V4_DOMAIN_PATTERN =
"/^(\\d{1,3})[.](\\d{1,3})[.](\\d{1,3})[.](\\d{1,3})$/";
private static final String DOMAIN_PATTERN =
"/^" + ATOM + "(\\." + ATOM + ")*$/";
private static final String PORT_PATTERN = "/^:(\\d{1,5})$/";
private static final String ATOM_PATTERN = "/(" + ATOM + ")/";
private static final String ALPHA_PATTERN = "/^[" + ALPHA_CHARS + "]/";
/**
* Holds the set of current validation options.
*/
private Flags options = null;
/**
* The set of schemes that are allowed to be in a URL.
*/
private Set 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);
}
/**
* 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;
}
Perl5Util matchUrlPat = new Perl5Util();
Perl5Util matchAsciiPat = new Perl5Util();
if (!matchAsciiPat.match(LEGAL_ASCII_PATTERN, value)) {
return false;
}
// Check the whole url address structure
if (!matchUrlPat.match(URL_PATTERN, value)) {
return false;
}
if (!isValidScheme(matchUrlPat.group(PARSE_URL_SCHEME))) {
return false;
}
if (!isValidAuthority(matchUrlPat.group(PARSE_URL_AUTHORITY))) {
return false;
}
if (!isValidPath(matchUrlPat.group(PARSE_URL_PATH))) {
return false;
}
if (!isValidQuery(matchUrlPat.group(PARSE_URL_QUERY))) {
return false;
}
if (!isValidFragment(matchUrlPat.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;
}
Perl5Util schemeMatcher = new Perl5Util();
if (!schemeMatcher.match(SCHEME_PATTERN, scheme)) {
return false;
}
if (this.options.isOff(ALLOW_ALL_SCHEMES)) {
if (!this.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;
}
Perl5Util authorityMatcher = new Perl5Util();
Perl5Util matchIPV4Pat = new Perl5Util();
if (!authorityMatcher.match(AUTHORITY_PATTERN, authority)) {
return false;
}
boolean ipV4Address = false;
boolean hostname = false;
// check if authority is IP address or hostname
String hostIP = authorityMatcher.group(PARSE_AUTHORITY_HOST_IP);
ipV4Address = matchIPV4Pat.match(IP_V4_DOMAIN_PATTERN, hostIP);
if (ipV4Address) {
// this is an IP address so check components
for (int i = 1; i <= 4; i++) {
String ipSegment = matchIPV4Pat.group(i);
if (ipSegment == null || ipSegment.length() <= 0) {
return false;
}
try {
if (Integer.parseInt(ipSegment) > 255) {
return false;
}
} catch(NumberFormatException e) {
return false;
}
}
} else {
// Domain is hostname name
Perl5Util domainMatcher = new Perl5Util();
hostname = domainMatcher.match(DOMAIN_PATTERN, hostIP);
}
//rightmost hostname will never start with a digit.
if (hostname) {
String[] domainSegment = new String[10];
boolean match = true;
int segmentCount = 0;
int segmentLength = 0;
Perl5Util atomMatcher = new Perl5Util();
while (match) {
match = atomMatcher.match(ATOM_PATTERN, hostIP);
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) {
return false;
}
// First letter of top level must be a alpha
Perl5Util alphaMatcher = new Perl5Util();
if (!alphaMatcher.match(ALPHA_PATTERN, topLevel.substring(0, 1))) {
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) {
Perl5Util portMatcher = new Perl5Util();
if (!portMatcher.match(PORT_PATTERN, port)) {
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;
}
Perl5Util pathMatcher = new Perl5Util();
if (!pathMatcher.match(PATH_PATTERN, path)) {
return false;
}
int slash2Count = countToken("//", path);
if (this.options.isOff(ALLOW_2_SLASHES) && (slash2Count > 0)) {
return false;
}
int slashCount = countToken("/", path);
int dot2Count = countToken("..", path);
if (dot2Count > 0) {
if ((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;
}
Perl5Util queryMatcher = new Perl5Util();
return queryMatcher.match(QUERY_PATTERN, query);
}
/**
* 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 this.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;
}
}