In the configuration of Ranger Presto plugin service, password is not a required content. Only when SSL is enabled in Presto, we need to fill in the password. When Presto does not enable SSL, if you fill in the password when configuring the service, the connection will fail and an exception will be thrown.
However, currently in the code, we always put prop.getProperty(HadoopConfigHolder.RANGER_LOGIN_PASSWORD) to prestoProperties, if the password is not set, prop.getProperty(HadoopConfigHolder.RANGER_LOGIN_PASSWORD) will be null. If we put a null value to Properties, this will throw NPE. We need to check whether we have set the password.