前言
前文中讲到，使用@ResponseStatus注解，可以修饰一个异常类，在发生异常的时候返回指定的错误码和消息，在返回的 reason中包含中文的时候，就会出现中文乱码的问题
现象
reason中包含中文的时候，前端返回为乱码
/**
* 自定义异常类
*
* @author Administrator
*
*/
@ResponseStatus(value = HttpStatus.FORBIDDEN, reason = "没有权限")
public class TestException extends RuntimeException {
private static final long serialVersionUID = 5759027883028274330L;
}
调用代码
/**
* 测试抛出异常乱码
*
* @return
*/
@RequestMapping(value = "/say", produces = "text/html;charset=UTF-8")
@ResponseBody
String say2() {
throw new TestException();
}
访问 http://localhost:8080/say2 返回乱码
原因
通过查看spring mvc 源码发现，解析这个 注解的类为 ResponseStatusExceptionResolver 主要是在resolveResponseStatus 中解析并 调用 response sendError 方法来想客户端发送 html 格式的异常消息，产生乱码的原因是因为编码格式不匹配，而这里明显没有 调用 response.setCharacterEncoding 方法。
public class ResponseStatusExceptionResolver extends AbstractHandlerExceptionResolver implements MessageSourceAware {
private MessageSource messageSource;
public void setMessageSource(MessageSource messageSource) {
this.messageSource = messageSource;
}
protected ModelAndView doResolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
{
ResponseStatus responseStatus = (ResponseStatus)AnnotatedElementUtils.findMergedAnnotation(ex.getClass(), ResponseStatus.class);
if (responseStatus != null);
try {
return resolveResponseStatus(responseStatus, request, response, handler, ex);
}
catch (Exception resolveEx) {
this.logger.warn("Handling of @ResponseStatus resulted in Exception", resolveEx);
break label81:
if (ex.getCause() instanceof Exception) {
ex = (Exception)ex.getCause();
return doResolveException(request, response, handler, ex); }
}
label81: return null;
}
protected ModelAndView resolveResponseStatus(ResponseStatus responseStatus, HttpServletRequest request,
HttpServletResponse response, Object handler, Exception ex) throws Exception {
int statusCode = responseStatus.code().value();
String reason = responseStatus.reason();
if (this.messageSource != null) {
reason = this.messageSource.getMessage(reason, null, reason, LocaleContextHolder.getLocale());
}
if (!(StringUtils.hasLength(reason))) {
response.sendError(statusCode);
} else {
response.sendError(statusCode, reason);
}
return new ModelAndView();
}
}
spring 是通过 CharacterEncodingFilter来设置 request 和 response 的编码格式的，查看代码如下，走到这一步，就要查看 spirng boot 是在哪里定义这个过滤器的
@Override
protected void doFilterInternal(
HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
if (this.encoding != null && (this.forceEncoding || request.getCharacterEncoding() == null)) {
request.setCharacterEncoding(this.encoding);
if (this.forceEncoding) {
response.setCharacterEncoding(this.encoding);
}
}
filterChain.doFilter(request, response);
}
查看代码，是在 HttpEncodingAutoConfiguration 这个配置类中设置的，代码如下 ，这里就用到一个属性类 HttpEncodingProperties 查看代码，调用的是 shouldForce 方法，所以只需一个设置，就可以让他强制设置编码格式 spring.http.encoding.force=true
public class HttpEncodingAutoConfiguration {
private final HttpEncodingProperties properties;
public HttpEncodingAutoConfiguration(HttpEncodingProperties properties) {
this.properties = properties;
}
@Bean
@ConditionalOnMissingBean({ CharacterEncodingFilter.class })
public CharacterEncodingFilter characterEncodingFilter() {
CharacterEncodingFilter filter = new OrderedCharacterEncodingFilter();
filter.setEncoding(this.properties.getCharset().name());
filter.setForceRequestEncoding(this.properties.shouldForce(HttpEncodingProperties.Type.REQUEST));
filter.setForceResponseEncoding(this.properties.shouldForce(HttpEncodingProperties.Type.RESPONSE));
return filter;
}
@Bean
public LocaleCharsetMappingsCustomizer localeCharsetMappingsCustomizer() {
return new LocaleCharsetMappingsCustomizer(this.properties);
}
private static class LocaleCharsetMappingsCustomizer implements EmbeddedServletContainerCustomizer, Ordered {
private final HttpEncodingProperties properties;
LocaleCharsetMappingsCustomizer(HttpEncodingProperties properties) {
this.properties = properties;
}
public void customize(ConfigurableEmbeddedServletContainer container) {
if (this.properties.getMapping() != null)
container.setLocaleCharsetMappings(this.properties.getMapping());
}
public int getOrder() {
return 0;
}
}
}
boolean shouldForce(Type type) {
Boolean force = (type == Type.REQUEST) ? this.forceRequest : this.forceResponse;
if (force == null) {
force = this.force;
}
if (force == null) {
force = Boolean.valueOf(type == Type.REQUEST);
}
return force.booleanValue();
}
解决办法
spring.http.encoding.force=true
结果
再次访问刷新，显示正常。
