build http entity and MessageConverter for RestTemplate

RestTemplateConfigSnippet.java

private HttpEntity buildHttpEntity(List<DataPowerRequest> request){
      HttpHeaders requestHeaders = new HttpHeaders();
      requestHeaders.setContentType(MediaType.APPLICATION_JSON);
      HttpEntity<List<DataPowerRequest>> entity = new HttpEntity<List<DataPowerRequest>>(request
      		, requestHeaders);
      return entity;
}
    
private void setHttpMessageConverter(RestTemplate restTemplate) {

    	if (restTemplate ==null) {
    		restTemplate = new RestTemplate();
    	}
        
        List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
        Jaxb2RootElementHttpMessageConverter jaxbMessageConverter = new Jaxb2RootElementHttpMessageConverter();
        List<MediaType> mediaTypes = new ArrayList<MediaType>();
        mediaTypes.add(MediaType.APPLICATION_JSON);
        jaxbMessageConverter.setSupportedMediaTypes(mediaTypes);
        messageConverters.add(jaxbMessageConverter);
        restTemplate.setMessageConverters(messageConverters);

}