Java – Cognito User Pool : How to use refreshToken to get new accessToken after accessToken gets expired in aws cognito java SDK?

I use AWS Cognito as my user management solution in a web application based on the Scala Play framework. I’m signing in with the following code.

var mIdentityProvider: AWSCognitoIdentityProvider = getAmazonCognitoIdentityClient;

def sessionLogin(userName: String, password: String): AdminInitiateAuthResult = {
val authParams: java.util.Map[String, String] = new java.util.HashMap[String, String]()
    authParams.put("USERNAME", userName)
    authParams.put("PASSWORD", password)
    val authRequest = new AdminInitiateAuthRequest()
      .withAuthFlow(AuthFlowType.ADMIN_NO_SRP_AUTH)
      .withUserPoolId("***")
      .withClientId("***")
      .withAuthParameters(authParams)
    val authResult = mIdentityProvider.adminInitiateAuth(authRequest)
    authResult
}

The above code returns accessToken, expiresIn, tokenType, refreshToken, and idToken from the AWS Cognito server 。
According to the AWS documentation, when an accessToken expires to continue a user session, we can use refreshToken to get a new accessToken or idToken. However, there is no mention in the documentation about how to use refreshToken for this purpose. Any help with this would be appreciated. Thanks in advance.

I figured it out myself. Here is the working code

def refreshAccessToken(refreshToken: String): AuthenticationResultType = {
    val authParams: java.util.Map[String, String] = new java.util.HashMap[String, String]()
    authParams.put("REFRESH_TOKEN", refreshToken)
    val authRequest = new AdminInitiateAuthRequest()
      .withAuthFlow(AuthFlowType.REFRESH_TOKEN_AUTH)
      .withUserPoolId("***")
      .withClientId("***")
      .withAuthParameters(authParams)
    val authResult = mIdentityProvider.adminInitiateAuth(authRequest)
    val resultType: AuthenticationResultType = authResult.getAuthenticationResult
    resultType
  }