Converting xml SOAPUI response to Java Object

Am a beginner in webservices, am working on consuming a webservice from a partner API which will act as the server, i have developed a Gateway application that will push requests to my API which will act as the client. i did this as the methods in my API and the partner's API do not match. i have explored the partner's API on SOAPUI and identified the method that i require, which i have pasted below:

<soapenv:Envelope xmlns:soapenv="http://ift.tt/sVJIaE" xmlns:hub="http://ift.tt/YCChdh">
<soapenv:Header/>
<soapenv:Body>
  <hub:validateAccount>
     <credentials>
        <username>?</username>
        <password>?</password>
     </credentials>
     <packet>
        <!--1 or more repetitions:-->
        <Item>
           <serviceID>?</serviceID>
           <serviceCode>?</serviceCode>
           <accountNumber>?</accountNumber>
           <requestExtraData>?</requestExtraData>
        </Item>
     </packet>
  </hub:validateAccount>
</soapenv:Body>
</soapenv:Envelope>

After submiting request to specified endpoint URL, i get the below response

<S:<S:Envelope xmlns:S="http://ift.tt/sVJIaE">
Body>
  <ns2:validateAccountResponse xmlns:ns2="http://ift.tt/YCChdh">
     <return>
        <authStatus>
           <authStatusCode>131</authStatusCode>
           <authStatusDescription>Authentication was a success</authStatusDescription>
        </authStatus>
        <results>
           <Item>
              <statusCode>307</statusCode>
              <statusDescription>Account number provided is valid</statusDescription>
              <serviceID>130</serviceID>
              <serviceCode/>
              <accountNumber>XXXXXXXX</accountNumber>
              <active>yes</active>
              <responseExtraData>{"Currency":"XXX","VALUE":"33.54","DueDate":"2014-09-12T00:00:00+07:00"}</responseExtraData>
           </Item>
        </results>
     </return>
  </ns2:validateAccountResponse>
</S:Body>
</S:Envelope>

I want to convert the response into a java object and use it in my GateWay but i dont know how to go about it. Can someone please assist me?