SpringMVC中文乱码踩坑

使用SpringMVC在返回一个字符串时发生了中文乱码问题。produces属性无效

@RequestMapping(value = "/nihao", produces = "text/plain;charset=UTF-8") @ResponseBody public String hello(HttpServletResponse response) throws UnsupportedEncodingException { User user = new User(); user.setSex("男"); user.setName("Clover"); user.setAge(19); return user.toString(); } HTTP/1.1 200 OK Server: Apache-Coyote/1.1 Content-Type: text/plain;charset=ISO-8859-1 Content-Length: 36 Date: Sun, 01 Aug 2021 12:20:21 GMT Connection: close { "name": "Clover", "sex": "?", "age": 19 }

添加常用的过滤器org.springframework.web.filter.CharacterEncodingFilter依然无法解决

<filter> <filter-name>characterEncodingFilter</filter-name> <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> <init-param> <param-name>encoding</param-name> <param-value>utf-8</param-value> </init-param> <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> 问题根源

最后查看源码时发现问题出现在处理内容协商的时候，SpringMVC使用了一个叫做org.springframework.http.converter.StringHttpMessageConverter的转换器进行处理java.lang.String。在这个处理器中，有个一默认的编码格式，它甚至使用了final修饰…..

public static final Charset DEFAULT_CHARSET = Charset.forName("ISO-8859-1");

并且，通过Postman或者REST Client发送请求时，Accept默认是*/*。

解决方案 方案一

注册一个StringHttpMessageConverter，注册之后不再使用SpringMVC默认的。它可以将produces设置为Content-Type。也就是说@RequestMapping的produces属性生效了

<mvc:annotation-driven> <mvc:message-converters> <bean/> </mvc:message-converters> </mvc:annotation-driven> HTTP/1.1 200 OK Server: Apache-Coyote/1.1 Accept-Charset: ... Content-Type: text/plain;charset=utf-8 Content-Length: 37 Date: Sun, 01 Aug 2021 13:09:35 GMT Connection: close { "name": "Clover", "sex": "男", "age": 19 } 方案二

Accept问题，SpringMVC的默认StringHttpMessageConverter处理的是*/*，那手动设置一个Accept尽可能避开它…..

POST {{url}}/nihao HTTP/1.1 Accept: text/plain;charset=utf-8 HTTP/1.1 200 OK Server: Apache-Coyote/1.1 Content-Type: text/plain;charset=utf-8 Content-Length: 38 Date: Sun, 01 Aug 2021 13:20:16 GMT Connection: close { "name": "Clover", "sex": "男", "age": 19 }