Java Spring resttemplate character encoding

Question

I'm using the Java Spring Resttemplate for getting a json via a get request. The JSON I'm getting has instead of special character slike ü ö ä or ß some weird stuff. So I guess somethings wrong with the character encoding. I can't find any help on the internet. The code I'm using for now is:

String json = restTemplate.getForObject(
    overPassStatementPostCode,
    String.class,
    params);

Answer 1

You just need to add the StringHttpMessageConverter to the template's message converters:

RestTemplate template = new RestTemplate();
template.getMessageConverters()
        .add(0, new StringHttpMessageConverter(Charset.forName("UTF-8")));
ResponseEntity<Object> response = template.exchange(endpoint, method, entity, 
                                                    Object.class);

Answer 2

First I tried @beerbajay 's way , but it not helps。 Finally I resolve it by below way

        RestTemplate template = new RestTemplate();
//      template.getMessageConverters()
//              .add(0, new StringHttpMessageConverter(Charset.forName("UTF-8")));
        HttpHeaders headers = new HttpHeaders();
        headers.setAccept(newArrayList(MediaType.APPLICATION_JSON));
        ResponseEntity<String> response = template.exchange(url, HttpMethod.GET, new HttpEntity<String>(headers), String.class);

Answer 3

I've same issue on this case, after one search, I've got this link: https://gist.github.com/knight1128/66f3e4817ab35c7397fd

its workaround is working for me:

package com.google.locationlab;

import com.google.common.collect.Lists;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.junit.Test;
import org.springframework.http.*;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;

import java.net.URI;
import java.nio.charset.Charset;
import java.util.List;

public class PortalRestTemplateIntegrationTest {
    private Log logger = LogFactory.getLog(PortalRestTemplateIntegrationTest.class);

    @Test
    public void test() throws Exception {
        RestTemplate restTemplate = new RestTemplate();

        HttpMessageConverter stringHttpMessageConverter = new StringHttpMessageConverter(Charset.forName("UTF-8"));
        List<HttpMessageConverter<?>> httpMessageConverter = Lists.newArrayList();
        httpMessageConverter.add(stringHttpMessageConverter);
        restTemplate.setMessageConverters(httpMessageConverter);

        URI targetUrl= UriComponentsBuilder.fromUriString("http://portal.net")
                .path("search")
                .queryParam("q", "잠실역")
                .build()
                .toUri();

        HttpHeaders headers = new HttpHeaders();
        Charset utf8 = Charset.forName("UTF-8");
        MediaType mediaType = new MediaType("text", "html", utf8);
        headers.setContentType(mediaType);
        headers.set("User-Agent", "mozilla");
        headers.set("Accept-Language", "ko"); 
        // gzip 사용하면 byte[] 로 받아서, 압축을 풀고 decoding 해야 한다. 

        HttpEntity<String> entity = new HttpEntity<String>("parameters", headers);
        ResponseEntity<String> responseEntity = restTemplate.exchange(targetUrl.toURL().toString(), HttpMethod.GET, entity, String.class);
        String result = responseEntity.getBody();

        logger.info(result);

    }
}

Answer 4

I have solved this problem. I need to POST a string object in request body with UTF-8.

text/plain

httpHeaders.setContentType(new MediaType("text", "plain", StandardCharsets.UTF_8));

applicaton/json

httpHeaders.setContentType(new MediaType("applicaton", "json", StandardCharsets.UTF_8));

RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> resposeEntity = null;

HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.setContentType(new MediaType("text", "plain", StandardCharsets.UTF_8));

HttpEntity<String> httpEntity = new HttpEntity<String>(stringContent, httpHeaders);
responseEntity = restTemplate.exchange(requestUrl, HttpMethod.POST, httpEntity, String.class);

if (HttpStatus.OK.equals(responseEntity.getStatusCode())) {
    logger.debug("... success ... result: " + responseEntity.getBody());
}

Answer 5

You can still use String.class as a response type if you can do the following.

Upgrading to spring-web 5.2 solves the problem. or set writeAcceptCharset property to false belongs to StringHttpMessageConverter and use that convertor further in RestTemplate instance.

boolean writeAcceptCharSet = false;
List<HttpMessageConverter<?>> c = restTemplate.getMessageConverters();
for (HttpMessageConverter<?> mc : c) {
  if (mc instanceof StringHttpMessageConverter) {
    StringHttpMessageConverter mcc = (StringHttpMessageConverter) mc;
    mcc.setWriteAcceptCharset(writeAcceptCharSet);
  }
}

Answer 6

In my case, I was using Postman. It was sending a hidden header of:

Accept-Encoding: gzip, deflate, br

I removed this header and my response came back correctly, instead of mumbo-jumbos.