How to send XML POST requests with Spring RestTemplate?

Question

Is it possible to send XML POST requests with spring, eg RestTemplate?

I want to send the following xml to the url localhost:8080/xml/availability

<AvailReq>
  <hotelid>123</hotelid>
</AvailReq>

Also do I want to add custom http headers on each request dynamically(!).

How could I achieve this with spring?

Answer 1

First of all, define your HTTP headers, like following:

HttpHeaders headers = new HttpHeaders();
headers.add("header_name", "header_value");

You can set any HTTP header with this approach. For well known headers you can use pre-defined methods. For example, in order to set Content-Type header:

headers.setContentType(MediaType.APPLICATION_XML);

Then define a HttpEntity or RequestEntity to prepare your request object:

HttpEntity<String> request = new HttpEntity<String>(body, headers);

If you somehow have access to the XML string, you can use HttpEntity<String>. Otherwise you can define a POJO corresponding to that XML. and finally send the request using postFor... methods:

ResponseEntity<String> response = restTemplate.postForEntity("http://localhost:8080/xml/availability", request, String.class);

Here i'm POSTing the request to the http://localhost:8080/xml/availability endpoint and converting the HTTP response body into a String.

Note, that in the above examples new HttpEntity<String>(...) can be replaced with new HttpEntity<>(...) using JDK7 and later.

Answer 2

Find below for example to use a RestTemplate to exchange XML as String and receive a response:

String xmlString = "<?xml version=\"1.0\" encoding=\"utf-8\"?><AvailReq><hotelid>123</hotelid></AvailReq>";

    RestTemplate restTemplate =  new RestTemplate();
    //Create a list for the message converters
    List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
    //Add the String Message converter
    messageConverters.add(new StringHttpMessageConverter());
    //Add the message converters to the restTemplate
    restTemplate.setMessageConverters(messageConverters);


    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_XML);
    HttpEntity<String> request = new HttpEntity<String>(xmlString, headers);

    final ResponseEntity<String> response = restTemplate.postForEntity("http://localhost:8080/xml/availability", request, String.class);

Answer 3

Below you find a complete example how to use a RestTemplate to exchange XML documents and receive a HTML response:

import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;
import static org.springframework.test.web.client.match.MockRestRequestMatchers.header;
import static org.springframework.test.web.client.match.MockRestRequestMatchers.content;
import static org.springframework.test.web.client.match.MockRestRequestMatchers.method;
import static org.springframework.test.web.client.match.MockRestRequestMatchers.requestTo;
import static org.springframework.test.web.client.response.MockRestResponseCreators.withSuccess;

import org.junit.Test;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.test.web.client.MockRestServiceServer;
import org.springframework.web.client.RestTemplate;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;

import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

public class XmlTest {

    @Test
    public void test() throws Exception {
        RestTemplate restTemplate = new RestTemplate();
        MockRestServiceServer mockServer = MockRestServiceServer.createServer(restTemplate);
        String htmlString = "<p>response</p>";
        String xmlString = "<?xml version=\"1.0\" encoding=\"utf-8\"?><AvailReq><hotelid>123</hotelid></AvailReq>";

        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder = factory.newDocumentBuilder();
        Document document = builder.parse(new InputSource(new StringReader(xmlString)));

        mockServer.expect(requestTo("http://localhost:8080/xml/availability"))
                .andExpect(method(HttpMethod.POST))
                .andExpect(content().string(is(xmlString)))
                .andExpect(header("header", "value"))
                .andRespond(withSuccess("<p>response</p>", MediaType.TEXT_HTML));

        HttpHeaders headers = new HttpHeaders();
        headers.add("header", "value");
        HttpEntity<Document> request = new HttpEntity<>(document, headers);

        final ResponseEntity<String> response = restTemplate.postForEntity("http://localhost:8080/xml/availability", request, String.class);

        assertThat(response.getBody(), is(htmlString));
        mockServer.verify();
    }
}