// Session variables
String adminUsername = "<administrator sAMAccountName value>";
String adminPwd = "<admin password>";
String userDN = "<DN for the user being updated>";
String newPwd = "<The new password for the user being updated>";
String ipAddress = "<AD ip address>";

// LDAP configuration
String securityProtocol = "sasl";
String providerURL = "ldap://" + ipAddress;

Hashtable<Object, Object> env = new Hashtable<>();
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.ldap.LdapCtxFactory");
env.put("javax.security.sasl.strength", "high");
env.put("javax.security.sasl.policy.noplaintext", "true");
env.put(Context.PROVIDER_URL, providerURL);
env.put(Context.SECURITY_AUTHENTICATION, "DIGEST-MD5");
env.put(Context.SECURITY_PRINCIPAL, adminUsername);
env.put(Context.SECURITY_CREDENTIALS, adminPwd);
env.put(Context.SECURITY_PROTOCOL, securityProtocol);
env.put(Context.REFERRAL, "follow");

// Prepare the modifications list
String newQuotedPassword = """ + newPwd + """;
byte[] newUnicodePassword = newQuotedPassword.getBytes("UTF-16LE");
ModificationItem[] mods = new ModificationItem[1];
mods[0] = new ModificationItem(DirContext.REPLACE_ATTRIBUTE,
        new BasicAttribute("unicodePwd", newUnicodePassword));

// Initiate the LDAP connection
LdapContext ctx = new InitialLdapContext(env, null);

// Modify the password
ctx.modifyAttributes(userDN, mods);

// Close LDAP connection
ctx.close();