如何在tomcat容器中的spring boot multipart controller action中捕获FileSizeLimitExceededException？

Question

当我上传大小超过配置的最大文件大小的文件时，返回的响应对我的 JS UI 不是很漂亮或有用。所以，我想抓住它并处理它。但是，问题是在输入我的控制器之前抛出错误。因此，我不知道在哪里放置我的错误处理代码。我正在考虑的一个想法是定义一个过滤器并在那里捕获它。这是正常的地方吗？我看到的堆栈跟踪是：

at org.apache.tomcat.util.http.fileupload.FileUploadBase$FileItemIteratorImpl$FileItemStreamImpl$1.raiseError(FileUploadBase.java:628) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.tomcat.util.http.fileupload.util.LimitedInputStream.checkLimit(LimitedInputStream.java:76) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.tomcat.util.http.fileupload.util.LimitedInputStream.read(LimitedInputStream.java:135) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at java.io.FilterInputStream.read(FilterInputStream.java:107) ~[na:1.8.0_121]
at org.apache.tomcat.util.http.fileupload.util.Streams.copy(Streams.java:98) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.tomcat.util.http.fileupload.util.Streams.copy(Streams.java:68) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.tomcat.util.http.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:293) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.connector.Request.parseParts(Request.java:2902) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.connector.Request.parseParameters(Request.java:3242) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.connector.Request.getParameter(Request.java:1136) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.connector.RequestFacade.getParameter(RequestFacade.java:381) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:84) ~[spring-web-5.0.9.RELEASE.jar!/:5.0.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.9.RELEASE.jar!/:5.0.9.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.9.RELEASE.jar!/:5.0.9.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.9.RELEASE.jar!/:5.0.9.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:806) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1498) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_121]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_121]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.34.jar!/:8.5.34]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_121]

我的控制器操作如下所示：

@PostMapping("/upload")
@ResponseBody
public String handleFileUpload(@RequestParam("file") MultipartFile file) {
    String fileName = storageService.store(file);
    String fileUrl = "/api/file/" + fileName;

    return "{\"fileUrl\":\"" + fileUrl + "\"}";
}

虽然这不是很重要，因为没有输入该代码，因为首先在线程中抛出异常。

正如预期的那样，出于同样的原因，向控制器添加异常处理程序并没有捕获异常。

@ExceptionHandler(FileUploadBase.FileSizeLimitExceededException.class)
public String handlefileSizeLimitExceeded(FileUploadBase.FileSizeLimitExceededException exc) {
    return "{\"error\":\"file too big\"}";
}

注意：我不是在问如何更改文件大小最大值。我已经知道该怎么做了。我的目标是在用户尝试上传大于最大值的文件时进行报告。

Answer 1

您需要捕获 MaxUploadSizeExceededException.class

@ExceptionHandler(MaxUploadSizeExceededException.class)
public String handleFileSizeLimitExceeded(MaxUploadSizeExceededException exc) {
    return "{\"error\":\"file too big\"}";
}