XML to POJO JAVA

I have read other posts related to this issue but I could not fix my problem. I try to convert the following XML String to a JAVA class but when I try to access param1 using getParam1() method it returns null and I am not sure why.

The XML String:

<?xml version="1.0" encoding="utf-8"?>
<REQUERYTRXRESPONSE xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://tempuri.org/">
 <param1>3gbahtJf1y85Oks4HrPLkqTQZV8Yg8pIhdXOrZ8pLGJP3FLwqKlIzIl/GgUpGvFaw4MC4SV+4pCudmVq+apIMIJJS4PrVyUx4T0ZO/Tsui4ZqCn62dLAG0DVhBVz2ZasF4yr7CRYnk47FWS0RywXmA==</param1>
 <param2>lO4ismiJwsvBiHQGW/UwCA==</param2>
 <param3 />
</REQUERYTRXRESPONSE>

The Java class:

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(namespace = "http://tempuri.org/", name =  "REQUERYTRXRESPONSE")
@XmlAccessorType(XmlAccessType.PROPERTY)
public class REQUERYTRXRESPONSE {
private String param1;
private String param2;
private String param3;

@XmlElement(required = true, name = "param1")
public String getParam1() {
    return param1;
}
public void setParam1(String param1) {
    this.param1 = param1;
}

@XmlElement(required = true, name = "param2")
public String getParam2() {
    return param2;
}
public void setParam2(String param2) {
    this.param2 = param2;
}

@XmlElement(required = true, name = "param3")
public String getParam3() {
    return param3;
}
public void setParam3(String param3) {
    this.param3 = param3;
}
}

The XML to Java class code:

HttpRequest httpRequest = HttpRequest.get();

    if (httpRequest.ok()) {
        String response = httpRequest.body();

        System.out.println(response);

        JAXBContext jaxbContext = JAXBContext.newInstance(REQUERYTRXRESPONSE.class);
        Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
        REQUERYTRXRESPONSE requerytrxresponse = (REQUERYTRXRESPONSE) unmarshaller.unmarshal(new StringReader(response));


        System.out.println((String) requerytrxresponse.getParam1()); // returns null
    }