org.jxmpp.util.XmppStringUtils Maven / Gradle / Ivy
/**
*
* Copyright © 2014-2019 Florian Schmaus
*
* 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.jxmpp.util;
import org.jxmpp.util.cache.LruCache;
/**
* Utility class for handling Strings in XMPP.
*/
public class XmppStringUtils {
/**
* Returns the localpart of an XMPP address (JID). For example, for the address "[email protected]/Resource", "user"
* would be returned. Returns null if the given JID has no localpart. Returns the empty string if
* the given JIDs localpart is the empty string (which is invalid).
*
* @param jid
* the XMPP address to parse.
* @return the name portion of the XMPP address, the empty String or null.
*/
public static String parseLocalpart(String jid) {
int atIndex = jid.indexOf('@');
if (atIndex < 0) {
return null;
}
if (atIndex == 0) {
// '@' as first character, i.e. '@example.org". Return empty string as
// localpart, to make it possible to differentiate this from 'example.org'
// (which would return 'null' as localpart).
return "";
}
int slashIndex = jid.indexOf('/');
if (slashIndex >= 0 && slashIndex < atIndex) {
// This is an '@' character in the resourcepart.
return null;
}
return jid.substring(0, atIndex);
}
/**
* Returns the domain of an XMPP address (JID). For example, for the address "[email protected]/Resource", "xmpp.org"
* would be returned. If jid is null, then this method returns also null. If
* the input String is no valid JID or has no domainpart, then this method will return the empty String.
*
* @param jid
* the XMPP address to parse.
* @return the domainpart of the XMPP address, the empty String or null.
*/
public static String parseDomain(String jid) {
if (jid == null) return null;
int atIndex = jid.indexOf('@');
int slashIndex = jid.indexOf('/');
if (slashIndex >= 0) {
// '[email protected]/resource' and '[email protected]/res@otherres' case
if (slashIndex > atIndex) {
return jid.substring(atIndex + 1, slashIndex);
// 'domain.foo/res@otherres' case
} else {
return jid.substring(0, slashIndex);
}
} else {
return jid.substring(atIndex + 1);
}
}
/**
* Returns the resource portion of an XMPP address (JID). For example, for the address "[email protected]/Resource",
* "Resource" would be returned. Returns null if the given JID has no resourcepart. Returns the
* empty string if the given JID has an empty resourcepart (which is invalid).
*
* @param jid
* the XMPP address to parse.
* @return the resource portion of the XMPP address.
*/
public static String parseResource(String jid) {
int slashIndex = jid.indexOf('/');
if (slashIndex < 0) {
return null;
}
if (slashIndex + 1 > jid.length()) {
return "";
} else {
return jid.substring(slashIndex + 1);
}
}
/**
* Returns the JID with any resource information removed. For example, for
* the address "[email protected]/Smack", "[email protected]" would
* be returned.
*
* @param jid
* the XMPP JID.
* @return the bare XMPP JID without resource information.
*/
public static String parseBareJid(String jid) {
int slashIndex = jid.indexOf('/');
if (slashIndex < 0) {
return jid;
} else if (slashIndex == 0) {
return "";
} else {
return jid.substring(0, slashIndex);
}
}
/**
* Returns true if jid is a full JID (i.e. a JID with resource part).
*
* @param jid the String to check.
* @return true if full JID, false otherwise
*/
public static boolean isFullJID(String jid) {
String domain = parseDomain(jid);
String resource = parseResource(jid);
if ((domain == null || domain.length() <= 0)
|| (resource == null || resource.length() <= 0)) {
return false;
}
return true;
}
/**
* Returns true if jid is a bare JID ("[email protected]").
*
* This method may return true for Strings that are not valid JIDs (e.g. because of Stringprep violations). Consider
* using org.jxmpp.jid.util.JidUtil.validateBareJid(String) from jxmpp-jid instead of this method as it
* exceptions provide a meaningful message string why the JID is not a bare JID and will also check for Stringprep
* errors.
*
*
* @param jid the String to check.
* @return true if bare JID, false otherwise
*/
public static boolean isBareJid(String jid) {
String domain = parseDomain(jid);
String resource = parseResource(jid);
return (domain != null && domain.length() > 0
&& (resource == null || resource.length() == 0));
}
private static final LruCache LOCALPART_ESCAPE_CACHE = new LruCache(100);
private static final LruCache LOCALPART_UNESCAPE_CACHE = new LruCache(100);
/**
* Escapes the localpart of a JID according to "JID Escaping" (XEP-0106).
* Escaping replaces characters prohibited by Nodeprep with escape sequences,
* as follows:
*
* Character mappings
* Unescaped Character Encoded Sequence <space> \20 " \22 & \26 ' \27 / \2f : \3a < \3c > \3e @ \40 \ \5c
*
*
* This process is useful when the localpart comes from an external source that doesn't
* conform to Nodeprep. For example, a username in LDAP may be "Joe Smith". Because
* the <space> character isn't a valid part of a localpart, the username should
* be escaped to "Joe\20Smith" before being made into a JID (e.g. "joe\[email protected]"
* after case-folding, etc. has been applied).
*
*
* All localpart escaping and un-escaping must be performed manually at the appropriate
* time; the JID class will not escape or un-escape automatically.
*
* @param localpart the localpart.
* @return the escaped version of the localpart.
* @see XEP-106: JID Escaping
*/
public static String escapeLocalpart(String localpart) {
if (localpart == null) {
return null;
}
String res = LOCALPART_ESCAPE_CACHE.lookup(localpart);
if (res != null) {
return res;
}
StringBuilder buf = new StringBuilder(localpart.length() + 8);
for (int i = 0, n = localpart.length(); i < n; i++) {
char c = localpart.charAt(i);
switch (c) {
case '"':
buf.append("\\22");
break;
case '&':
buf.append("\\26");
break;
case '\'':
buf.append("\\27");
break;
case '/':
buf.append("\\2f");
break;
case ':':
buf.append("\\3a");
break;
case '<':
buf.append("\\3c");
break;
case '>':
buf.append("\\3e");
break;
case '@':
buf.append("\\40");
break;
case '\\':
buf.append("\\5c");
break;
default: {
if (Character.isWhitespace(c)) {
buf.append("\\20");
} else {
buf.append(c);
}
}
}
}
res = buf.toString();
LOCALPART_ESCAPE_CACHE.put(localpart, res);
return res;
}
/**
* Un-escapes the localpart of a JID according to "JID Escaping" (XEP-0106).
* Escaping replaces characters prohibited by Nodeprep with escape sequences,
* as follows:
*
*
* Character mapping
* Unescaped Character Encoded Sequence <space> \20 " \22 & \26 ' \27 / \2f : \3a < \3c > \3e @ \40 \ \5c
*
*
* This process is useful when the localpart comes from an external source that doesn't
* conform to Nodeprep. For example, a username in LDAP may be "Joe Smith". Because
* the <space> character isn't a valid part of a localpart, the username should
* be escaped to "Joe\20Smith" before being made into a JID (e.g. "joe\[email protected]"
* after case-folding, etc. has been applied).
*
*
* All localpart escaping and un-escaping must be performed manually at the appropriate
* time; the JID class will not escape or un-escape automatically.
*
* @param localpart the escaped version of the localpart.
* @return the un-escaped version of the localpart.
* @see XEP-106: JID Escaping
*/
public static String unescapeLocalpart(String localpart) {
if (localpart == null) {
return null;
}
String res = LOCALPART_UNESCAPE_CACHE.lookup(localpart);
if (res != null) {
return res;
}
char[] localpartChars = localpart.toCharArray();
StringBuilder buf = new StringBuilder(localpartChars.length);
for (int i = 0, n = localpartChars.length; i < n; i++) {
compare: {
char c = localpart.charAt(i);
if (c == '\\' && i + 2 < n) {
char c2 = localpartChars[i + 1];
char c3 = localpartChars[i + 2];
switch(c2) {
case '2':
switch (c3) {
case '0':
buf.append(' ');
i += 2;
break compare;
case '2':
buf.append('"');
i += 2;
break compare;
case '6':
buf.append('&');
i += 2;
break compare;
case '7':
buf.append('\'');
i += 2;
break compare;
case 'f':
buf.append('/');
i += 2;
break compare;
}
break;
case '3':
switch (c3) {
case 'a':
buf.append(':');
i += 2;
break compare;
case 'c':
buf.append('<');
i += 2;
break compare;
case 'e':
buf.append('>');
i += 2;
break compare;
}
break;
case '4':
if (c3 == '0') {
buf.append("@");
i += 2;
break compare;
}
break;
case '5':
if (c3 == 'c') {
buf.append("\\");
i += 2;
break compare;
}
break;
}
}
buf.append(c);
}
}
res = buf.toString();
LOCALPART_UNESCAPE_CACHE.put(localpart, res);
return res;
}
/**
* Construct a JID String from the given parts.
*
* @param localpart the localpart.
* @param domainpart the domainpart.
* @return the constructed JID String.
*/
public static String completeJidFrom(CharSequence localpart, CharSequence domainpart) {
return completeJidFrom(localpart != null ? localpart.toString() : null, domainpart.toString());
}
/**
* Construct a JID String from the given parts.
*
* @param localpart the localpart.
* @param domainpart the domainpart.
* @return the constructed JID String.
*/
public static String completeJidFrom(String localpart, String domainpart) {
return completeJidFrom(localpart, domainpart, null);
}
/**
* Construct a JID String from the given parts.
*
* @param localpart the localpart.
* @param domainpart the domainpart.
* @param resource the resourcepart.
* @return the constructed JID String.
*/
public static String completeJidFrom(CharSequence localpart, CharSequence domainpart, CharSequence resource) {
return completeJidFrom(localpart != null ? localpart.toString() : null, domainpart.toString(),
resource != null ? resource.toString() : null);
}
/**
* Construct a JID String from the given parts.
*
* @param localpart the localpart.
* @param domainpart the domainpart.
* @param resource the resourcepart.
* @return the constructed JID String.
*/
public static String completeJidFrom(String localpart, String domainpart, String resource) {
if (domainpart == null) {
throw new IllegalArgumentException("domainpart must not be null");
}
int maxResLength = domainpart.length();
if (localpart != null) maxResLength += localpart.length() + 1;
if (resource != null) maxResLength += resource.length() + 1;
StringBuilder sb = new StringBuilder(maxResLength);
if (localpart != null) {
sb.append(localpart).append('@');
}
sb.append(domainpart);
if (resource != null) {
sb.append('/').append(resource);
}
return sb.toString();
}
/**
* Generate a unique key from a element name and namespace. This key can be used to lookup element/namespace
* information. The key is simply generated by concatenating the strings as follows:
* element + '\t' + namespace.
*
* The tab character (\t) was chosen because it will be normalized, i.e. replace by space, in attribute values. It
* therefore should never appear in element or namespace. For more information about the
* normalization, see the XML specification § 3.3.3
* Attribute-Value Normalization.
*
*
* @param element the element.
* @param namespace the namespace.
* @return the unique key of element and namespace.
*/
public static String generateKey(String element, String namespace) {
return element + '\t' + namespace;
}
}