Best Pattern to replace an util class

I have a class like an util, It contains all preparing and calling requests (I want easily to manage requests). Ex:

public void reqLogin(String emailAddress, String password) {
    JsonRequestBody parameters = new JsonRequestBody();
    parameters.put(USER_NAME, emailAddress);
    parameters.put(PASSWORD, password);
    mService.login(parameters.createRequestBody());
}
public void reqRegister(LocationWrapper location) {
    JsonRequestBody jsonRequestBody = new JsonRequestBody();
    jsonRequestBody.put(DEVICE_TOKEN, "myToken");
    jsonRequestBody.put(DEVICE_TOKEN_TYPE, "type");
    mService.register(jsonRequestBody.createRequestBody());
}

... 

But problem of this design is that in LoginFragment I can call Register request, and in RegisterFragment I can call Login request. So, is it bad solution to create this util class? Is there a pattern to solve my issue?