Sample LDAP authentication and fetching information form LDAP.

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import javax.naming.directory.Attributes;
import javax.naming.directory.SearchControls;
import javax.naming.directory.SearchResult;
import javax.naming.ldap.InitialLdapContext;
import javax.naming.ldap.LdapContext;

import com.sun.tools.xjc.reader.xmlschema.bindinfo.BIConversion.User;

public class RetrieveUserAttributes {

public static void main(String[] args) {
RetrieveUserAttributes retrieveUserAttributes = new RetrieveUserAttributes();
retrieveUserAttributes.getLdapContext();
retrieveUserAttributes.getUserBasicAttributes("skummitha", retrieveUserAttributes.getLdapContext());
}

public LdapContext getLdapContext(){ //used for LDAP authentication
LdapContext ctx = null;
try{
Hashtable env = new Hashtable();
env.put(Context.INITIAL_CONTEXT_FACTORY,"com.sun.jndi.ldap.LdapCtxFactory");
env.put(Context.SECURITY_AUTHENTICATION, "Simple");
env.put(Context.SECURITY_PRINCIPAL, "domainname\\username");
env.put(Context.SECURITY_CREDENTIALS, "password");
env.put(Context.PROVIDER_URL, "ldap://127.0.0.1:389"); // LDAP URL
ctx = new InitialLdapContext(env, null);
System.out.println("Connection Successful.");
}catch(NamingException nex){
System.out.println("LDAP Connection: FAILED");
nex.printStackTrace();
}
return ctx;
}

private User getUserBasicAttributes(String username, LdapContext ctx) {
User user=null;
try {

SearchControls constraints = new SearchControls();
constraints.setSearchScope(SearchControls.SUBTREE_SCOPE);
String[] attrIDs = { "distinguishedName", // fetching information from LDAP what ever we want
"title",
"sn",
"givenname",
"mail",
"telephonenumber"};
constraints.setReturningAttributes(attrIDs);
//First input parameter is search bas, it can be "CN=Users,DC=YourDomain,DC=com"
//Second Attribute can be uid=username
NamingEnumeration<SearchResult> answer = ctx.search("DC=YourDomain,DC=com", "sAMAccountName="+ username, constraints);
if (answer.hasMore()) {
Attributes attrs = ((SearchResult) answer.next()).getAttributes();
System.out.println("distinguishedName "+ attrs.get("distinguishedName"));
System.out.println("givenname "+ attrs.get("givenname"));
System.out.println("tittle "+ attrs.get("title"));
System.out.println("sn "+ attrs.get("sn"));
System.out.println("mail "+ attrs.get("mail"));
System.out.println("telephonenumber "+ attrs.get("telephonenumber"));
}else{
throw new Exception("Invalid User");
}

} catch (Exception ex) {
ex.printStackTrace();
}
return user;
}

}