Question

当我上传的文件大小超过配置的最大文件大小时，返回的响应对我的JS UI来说不是很漂亮，也不有用。所以，我想抓住它并处理它。但是，问题是在进入控制器之前引发了错误。因此，我对将错误处理代码放在何处感到困惑。我想用的一个想法是定义一个过滤器并将其捕获。那是正常的地方吗？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]

我的控制器动作如下：

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

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

这并不是很重要，因为未输入该代码是因为在线程首先进入该异常时抛出了异常。

按预期，由于相同的原因，向控制器添加异常处理程序未捕获到异常。

@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最大文件大小。我已经知道该怎么做。我的目标是报告用户何时尝试上传大于最大大小的文件。

Answer 1

您需要捕获MaxUploadSizeExceededException.class

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

Answer 2

我遇到了同样的问题，另一个答案对我不起作用，所以继续寻找并找到了这个：https://www.baeldung.com/spring-maxuploadsizeexceeded （一如既往，baeldung.com 上的优秀指南，谢谢！）。检查 Tomcat 配置部分，它解释了为什么即使在使用 ExceptionHandler

我将分享对我有用的东西，使用带有嵌入式 Tomcat 的 Spring Boot v2.3.4。我想允许 10 MB 的文件并向用户显示错误消息

将此添加到 application.yml

#Configuration for size of files that can be uploaded
#Set Tomcat to accept any file size for failed upload
server.tomcat.max-swallow-size: -1
#set the Spring max file size for upload
spring.servlet.multipart:
    max-file-size: 10MB
    max-request-size: 10MB

然后我添加了一个 @ControllerAdvice 就像指南说的那样。请注意，仅向处理上传的控制器添加 @ExceptionHandler 是行不通的。

@Slf4j
@ControllerAdvice
public class FileUploadExceptionAdvice {


    @ExceptionHandler(MaxUploadSizeExceededException.class)
    public ResponseEntity<String> handleMaxUploadSizeExceededException(Exception ex){
        log.warn("Handling MaxUploadSizeExceededException: {}",ex.getMessage());

       
        return ResponseEntity.status(HttpStatus.PAYLOAD_TOO_LARGE)
                .contentType(MediaType.TEXT_PLAIN)
                .body("Message for user");
    }
}

在我的例子中，我想返回一些纯文本，以便在处理上传并显示错误的 JS 库中使用（这个非常好：https://www.dropzonejs.com/）。

您可以根据需要更改处理方式：一些 JSON 错误消息，或显示带有错误消息的页面，如指南。

请注意，如果您的错误消息需要 i18n，您可以在异常处理程序中检索 Locale，只需将其添加为方法的参数即可。看起来像这样：

@Slf4j
@ControllerAdvice
public class FileUploadExceptionAdvice {
    @Value("${spring.servlet.multipart.max-file-size}")
    private String maxFileSize;

    private final MessageSource messageSource;

    public FileUploadExceptionAdvice(MessageSource messageSource){
        this.messageSource=messageSource;
    }

 @ExceptionHandler(MaxUploadSizeExceededException.class)
    public ResponseEntity<String> handleMaxUploadSizeExceededException(Locale locale, Exception ex){

        String errorMessage = messageSource.getMessage("max.upload.size.exceeded", new Object[]{maxFileSize}, locale);
//use errorMessage in return handling
   }
}

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

2 个答案: