StringHttpMessageConverter DEFAULT_CHARSET Limitation for Turkish Content

Spring has its own REST support known as Spring Web MVC. Although, I am happy with its general capabilities, I came up with a small but very annoying problem or let’s say limitation related with its one of HttpMessageConverter‘s classes.

Spring Web MVC make use of HttpMessageConverter classes both on server and client to handle HTTP requests and generate responses as well, and one of those converters is StringHttpMessageConverter. It is very easy to generate String response via this converter and @ResponseBody annotation. For example;

public class StringResponseBodyTestController {
	public String hello() {
		return "hello world";

StringHttpMessageConverter looks for HTTP request’s Accept Header, and tries to extract charset parameter out of it. If it can’t then, it uses DEFAULT_CHARSET constant value which is ISO-8859-1. Unfortunately, content which has some special Turkish characters won’t display correctly with the default charset.

public String hello() {
return "hello world - ıİğĞşŞ";

It is easy to set Accept header value if you are using a REST client utility, e.g. Spring’s RestTemplate.

RestTemplate template = new RestTemplate();

HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.set("Accept", "text/html;charset=utf-8");

HttpEntity<?> requestEntity =
new HttpEntity(requestHeaders);

HttpEntity response = template.exchange(
"http://localhost/hello", HttpMethod.GET,
requestEntity, String.class);


However, if you are trying to access your REST services via browser, then you will have problem. Because, adding TR among your preferred languages won’t help, as this causes Accept-Language header to change only. As you see from the above example, we need to add “charset=utf-8” parameter to Accept header. If you are using firefox, the only possible way as far as I know is to use an add-on, like Modify Headers, or HeaderTool.

The bad thing about StringHttpMessageConverter is that it doesn’t provide any facility to change this behaviour. Currently, there are several issues in Spring JIRA system which as for a fix or enhancement to this HttpMessageConverter.

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