Spring resttemplate post json with utf-8

Aug 18, 2017

In Spring framework RestTemplate is very useful in terms of sending various http requests to RESTful resources and this post shows simple examples on how to set Content-Type, Accept headers, as well as the content encoding, which is especially important when requesting with non-ascii (e.g. CJK languages) data.

Initialize RestTemplate

import java.nio.Charset;
import java.util.Arrays;
import org.springframework.web.client.RestTemplate;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpEntity;
import org.springframework.http.MediaType;
import org.springframework.http.converter.StringHttpMessageConverter;
import com.fasterxml.jackson.databind.ObjectMapper;

RestTemplate restTemplate = new RestTemplate();

Set Content-Type

HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.setContentType(MediaType.APPLICATION_JSON);

Set Accept

headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
headers.setAcceptCharset(Arrays.asList(Charset.forName("UTF-8")));

Set encoding - option 1

restTemplate
    .getMessageConverters()
    .add(0, new StringHttpMessageConverter(Charset.forName("UTF-8")));

Set encoding - option 2

MediaType mediaType = new MediaType("application", "json", Charset.forName("UTF-8"));
httpHeaders.setContentType(mediaType);

Post request

XObject xObject = new XObject();
xObject.setFieldA("a");
xObject.setFieldB("b");
ObjectMapper objectMapper = new ObjectMapper();
String payload = objectMapper.writeValueAsString(xObject);
HttpEntity<String> httpEntity = new HttpEntity<String>(payload, httpHeaders);
YObject yObject = restTemplate.postForObject(httpUrl, httpEntity, YObject.class);