writeAcceptCharset must set to FALSE!
Tags: java, spring, tutorial
Published: 2021-11-11 08:21:13

In most case, `StringHttpMessageConverter` will be set for ANY string response in Servlet context config.
If you have prior Spring 5.2, you must set `writeAcceptCharset` to `false` for unwanted huge response header.
If `writeAcceptCharset` is `true`, by default, and request like `curl -i`, you'll see HUGE header content like this:

```
Accept-Charset:big5, big5-hkscs, compound_text, euc-jp, euc-kr, gb18030, gb2312, gbk, ibm-thai, ibm00858, ibm01140, ibm01141, ibm01142, ibm01143, ibm01144, ibm01145, ibm01146, ibm01147, ibm01148, ibm01149, ibm037, ibm1026, ibm1047, ibm273, ibm277, ibm278, ibm280, ibm284, ibm285, ibm297, ibm420, ibm424, ibm437, ibm500, ibm775, ibm850, ibm852, ibm855, ibm857, ibm860, ibm861, ibm862, ibm863, ibm864, ibm865, ibm866, ibm868, ibm869, ibm870, ibm871, ibm918, iso-2022-cn, iso-2022-jp, iso-2022-jp-2, iso-2022-kr, iso-8859-1, iso-8859-13, iso-8859-15, iso-8859-2, iso-8859-3, iso-8859-4, iso-8859-5, iso-8859-6, iso-8859-7, iso-8859-8, iso-8859-9, jis_x0201, jis_x0212-1990, koi8-r, koi8-u, shift_jis, tis-620, us-ascii, utf-16, utf-16be, utf-16le, utf-32, utf-32be, utf-32le, utf-8, windows-1250, windows-1251, windows-1252, windows-1253, windows-1254, windows-1255, windows-1256, windows-1257, windows-1258, windows-31j, x-big5-solaris, x-euc-jp-linux, x-euc-tw, x-eucjp-open, x-ibm1006, x-ibm1025, x-ibm1046, x-ibm1097, x-ibm1098, x-ibm1112, x-ibm1122, x-ibm1123, x-ibm1124, x-ibm1381, x-ibm1383, x-ibm33722, x-ibm737, x-ibm834, x-ibm856, x-ibm874, x-ibm875, x-ibm921, x-ibm922, x-ibm930, x-ibm933, x-ibm935, x-ibm937, x-ibm939, x-ibm942, x-ibm942c, x-ibm943, x-ibm943c, x-ibm948, x-ibm949, x-ibm949c, x-ibm950, x-ibm964, x-ibm970, x-iscii91, x-iso-2022-cn-cns, x-iso-2022-cn-gb, x-iso-8859-11, x-jis0208, x-jisautodetect, x-johab, x-macarabic, x-maccentraleurope, x-maccroatian, x-maccyrillic, x-macdingbat, x-macgreek, x-machebrew, x-maciceland, x-macroman, x-macromania, x-macsymbol, x-macthai, x-macturkish, x-macukraine, x-ms932_0213, x-ms950-hkscs, x-mswin-936, x-pck, x-sjis_0213, x-utf-16le-bom, x-utf-32be-bom, x-utf-32le-bom, x-windows-50220, x-windows-50221, x-windows-874, x-windows-949, x-windows-950, x-windows-iso2022jp
```

1834 bytes hell.

So, how can you remove this hell? simple. just call a setter method like this:

```xml
	<mvc:annotation-driven>
	    <mvc:message-converters>
	        <bean class="org.springframework.http.converter.StringHttpMessageConverter">
	            <property name="supportedMediaTypes">
	                <list>
	                    <value>text/html;charset=UTF-8</value>
	                </list>
	            </property>
				<property name="writeAcceptCharset" value="false"/>
	        </bean>
	    </mvc:message-converters>
	</mvc:annotation-driven>
```

```java
    @Bean
    public HttpMessageConverter<String> responseBodyConverter() {
        StringHttpMessageConverter converter = new StringHttpMessageConverter(StandardCharsets.UTF_8);
        converter.setSupportedMediaTypes(Arrays.asList(new MediaType("text", "plain", Charset.forName("UTF-8"))));
        converter.setWriteAcceptCharset(false);
        return converter;
    }
```

after Spring 5.2, `writeAcceptCharset` is `false` by default. don't worry about it.

Happy Coding!