com.nimbusds.ldap.dnresolver.TemplateResolver Maven / Gradle / Ivy
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package com.nimbusds.ldap.dnresolver;
import com.unboundid.ldap.sdk.*;
/**
* Resolves a directory object's DN using template substitution.
*
* This class is specifically intended to resolve a user's DN based on a
* unique fragment contained in its RDN, such as an UID, name or email address.
* Every occurence of a "%u" placeholder in the template is replaced by the
* provided input string.
*
*
Example: Resolving a user's DN based on their username (which is used as
* the value part of the RDN):
*
*
* - Input is "jbrown"
*
- DN template is "uid=%u,ou=people,dc=example,dc=com"
*
- The resolved DN is "uid=jbrown,ou=people,dc=example,dc=com"
*
*
* This is the simplest and most efficient method to resolve a user's DN.
* It doesn't require any LDAP requests (search) to be sent to the back-end
* directory. Note, however, that the actual existence of the DN is not
* verified!
*/
public class TemplateResolver implements DNResolver {
/**
* The DN template.
*/
final String template;
/**
* Creates a new DN resolver based on a DN template.
*
* @param template The DN template, must contain a "%u" placeholder.
*
* @throws IllegalArgumentException If the DN template is invalid.
*/
public TemplateResolver(final String template) {
if (! isValidTemplate(template))
throw new IllegalArgumentException("Bad DN template");
this.template = template;
}
/**
* Returns {@code false} if the specified template doesn't contain at
* least one "%u" placeholder or the final string doesn't represent a
* valid DN.
*
* @param template The DN template string to validate.
*
* @return {@code true} if the the template is valid, else {@code false}.
*/
public static boolean isValidTemplate(final String template) {
if (template == null)
return false;
if (template.indexOf("%u") == -1)
return false;
final String testUsername = "user001";
final String dnString = template.replaceAll("%u", testUsername);
try {
new DN(dnString);
} catch (LDAPException e) {
return false;
}
return true;
}
@Override
public DN resolve(final String attribute)
throws DNResolveException {
if (attribute == null || attribute.isEmpty())
throw new IllegalArgumentException("Bad attribute value: must not be null or empty string");
final String dnString = template.replaceAll("%u", attribute);
try {
return new DN(dnString);
} catch (LDAPException e) {
throw new DNResolveException("The syntax of the resolved DN is invalid");
}
}
}