public LdapContext connetLDAP() throws NamingException {  // 连接Ldap需要的信息  String ldapFactory = "com.sun.jndi.ldap.LdapCtxFactory";  String ldapUrl = "ldap:/IP:port";// url  String ldapAccount = "cn=root"; // 用户名  String ldapPwd = "password";//密码  Hashtable env = new Hashtable();  env.put(Context.INITIAL_CONTEXT_FACTORY, ldapFactory);  // LDAP server  env.put(Context.PROVIDER_URL, ldapUrl);  env.put(Context.SECURITY_AUTHENTICATION, "simple");  env.put(Context.SECURITY_PRINCIPAL, ldapAccount);  env.put(Context.SECURITY_CREDENTIALS, ldapPwd);  env.put("java.naming.referral", "follow");  LdapContext ctxTDS = new InitialLdapContext(env, null);  return ctxTDS;  
}