详解Springboot自定义异常处理
背景
Springboot默认把异常的处理集中到一个ModelAndView中了，但项目的实际过程中，这样做，并不能满足我们的要求。具体的自定义异常的处理，参看以下
具体实现
如果仔细看完springboot的异常处理详解，并且研究过源码后，我觉得具体的实现可以不用看了。。。
重写定义错误页面的url，默认只有一个/error
@Bean
publicEmbeddedServletContainerCustomizercontainerCustomizer(){
returnnewEmbeddedServletContainerCustomizer(){
@Override
publicvoidcustomize(ConfigurableEmbeddedServletContainercontainer){
container.addErrorPages(newErrorPage(HttpStatus.NOT_FOUND,"/error/404"));
container.addErrorPages(newErrorPage(HttpStatus.INTERNAL_SERVER_ERROR,"/error/500"));
container.addErrorPages(newErrorPage(java.lang.Throwable.class,"/error/500"));
}
};
}
重写通过实现ErrorController，重写BasicErrorController的功能实现
/**
*重写BasicErrorController,主要负责系统的异常页面的处理以及错误信息的显示
*@seeorg.springframework.boot.autoconfigure.web.BasicErrorController
*@seeorg.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration
*
*@authorJonathan
*@version2016/5/3111:22
*@sinceJDK7.0+
*/
@Controller
@RequestMapping(value="error")
@EnableConfigurationProperties({ServerProperties.class})
publicclassExceptionControllerimplementsErrorController{
privateErrorAttributeserrorAttributes;
@Autowired
privateServerPropertiesserverProperties;
/**
*初始化ExceptionController
*@paramerrorAttributes
*/
@Autowired
publicExceptionController(ErrorAttributeserrorAttributes){
Assert.notNull(errorAttributes,"ErrorAttributesmustnotbenull");
this.errorAttributes=errorAttributes;
}
/**
*定义404的ModelAndView
*@paramrequest
*@paramresponse
*@return
*/
@RequestMapping(produces="text/html",value="404")
publicModelAndViewerrorHtml404(HttpServletRequestrequest,
HttpServletResponseresponse){
response.setStatus(getStatus(request).value());
Mapmodel=getErrorAttributes(request,
isIncludeStackTrace(request,MediaType.TEXT_HTML));
returnnewModelAndView("error/404",model);
}
/**
*定义404的JSON数据
*@paramrequest
*@return
*/
@RequestMapping(value="404")
@ResponseBody
publicResponseEntity>error404(HttpServletRequestrequest){
Mapbody=getErrorAttributes(request,
isIncludeStackTrace(request,MediaType.TEXT_HTML));
HttpStatusstatus=getStatus(request);
returnnewResponseEntity>(body,status);
}
/**
*定义500的ModelAndView
*@paramrequest
*@paramresponse
*@return
*/
@RequestMapping(produces="text/html",value="500")
publicModelAndViewerrorHtml500(HttpServletRequestrequest,
HttpServletResponseresponse){
response.setStatus(getStatus(request).value());
Mapmodel=getErrorAttributes(request,
isIncludeStackTrace(request,MediaType.TEXT_HTML));
returnnewModelAndView("error/500",model);
}
/**
*定义500的错误JSON信息
*@paramrequest
*@return
*/
@RequestMapping(value="500")
@ResponseBody
publicResponseEntity>error500(HttpServletRequestrequest){
Mapbody=getErrorAttributes(request,
isIncludeStackTrace(request,MediaType.TEXT_HTML));
HttpStatusstatus=getStatus(request);
returnnewResponseEntity>(body,status);
}
/**
*Determineifthestacktraceattributeshouldbeincluded.
*@paramrequestthesourcerequest
*@paramproducesthemediatypeproduced(or{@codeMediaType.ALL})
*@returnifthestacktraceattributeshouldbeincluded
*/
protectedbooleanisIncludeStackTrace(HttpServletRequestrequest,
MediaTypeproduces){
ErrorProperties.IncludeStacktraceinclude=this.serverProperties.getError().getIncludeStacktrace();
if(include==ErrorProperties.IncludeStacktrace.ALWAYS){
returntrue;
}
if(include==ErrorProperties.IncludeStacktrace.ON_TRACE_PARAM){
returngetTraceParameter(request);
}
returnfalse;
}
/**
*获取错误的信息
*@paramrequest
*@paramincludeStackTrace
*@return
*/
privateMapgetErrorAttributes(HttpServletRequestrequest,
booleanincludeStackTrace){
RequestAttributesrequestAttributes=newServletRequestAttributes(request);
returnthis.errorAttributes.getErrorAttributes(requestAttributes,
includeStackTrace);
}
/**
*是否包含trace
*@paramrequest
*@return
*/
privatebooleangetTraceParameter(HttpServletRequestrequest){
Stringparameter=request.getParameter("trace");
if(parameter==null){
returnfalse;
}
return!"false".equals(parameter.toLowerCase());
}
/**
*获取错误编码
*@paramrequest
*@return
*/
privateHttpStatusgetStatus(HttpServletRequestrequest){
IntegerstatusCode=(Integer)request
.getAttribute("javax.servlet.error.status_code");
if(statusCode==null){
returnHttpStatus.INTERNAL_SERVER_ERROR;
}
try{
returnHttpStatus.valueOf(statusCode);
}
catch(Exceptionex){
returnHttpStatus.INTERNAL_SERVER_ERROR;
}
}
/**
*实现错误路径,暂时无用
*@seeExceptionMvcAutoConfiguration#containerCustomizer()
*@return
*/
@Override
publicStringgetErrorPath(){
return"";
}
}
总结
第一步，通过定义containerCustomizer,重写定义了异常处理对应的视图。目前定义了404和500，可以继续扩展。
第二步，重写BasicErrorController,当然可以直接定义一个普通的controller类，直接实现第一步定义的视图的方法。重写的目的是重用ErrorAttributes。这样在页面，直接可以获取到status,message,exception,trace等内容。
如果仅仅是把异常处理的视图作为静态页面，不需要看到异常信息内容的话，直接第一步后，再定义error/404，error/500等静态视图即可。
ErrorController根据Accept头的内容，输出不同格式的错误响应。比如针对浏览器的请求生成html页面，针对其它请求生成json格式的返回
以上两步的操作，比网上流传的更能实现自定义化。希望对大家的学习有所帮助，也希望大家多多支持毛票票。