java - 处理 MaxUploadSizeExceededException 不能停止上传文件

Question

我想检查上传文件的大小并阻止文件完全加载到内存中。我正在使用 CommonsMultipartFile。上传的文件将被处理并保存在数据库中。 AbstractCoupleUploadController 类处理包含文件的传入请求:

public abstract class AbstractCoupleUploadController<T extends Serializable> extends RemoteServiceServlet implements ServletContextAware,
        UploadServlet<WorkshopHistoryModel>
{
    ...

    @RequestMapping(method={RequestMethod.GET,RequestMethod.POST})
    public ModelAndView handleRequest(@RequestParam("firstFile") CommonsMultipartFile firstFile,
            @RequestParam("secondFile") CommonsMultipartFile secondFile, HttpServletRequest request, HttpServletResponse response)
    {
        synchronized(this)
        {
            initThreads();
            perThreadRequest.set(request);
            perThreadResponse.set(response);
        }

        handleUpload(firstFile,secondFile,request,response);
        response.getWriter().flush();
        response.flushBuffer();
        return null;
    }

    private void handleUpload(CommonsMultipartFile firstFile, CommonsMultipartFile secondFile, HttpServletRequest request,
        HttpServletResponse response) throws IOException
    {
        response.setContentType("text/html");
        if(firstFile.getSize() == 0 || secondFile.getSize() == 0)
        {
            response.getWriter().print(AppConstants.UPLOAD_ZERO_SIZE_FILE);
            return;
        }

        // other validations
        // uploading:
        try
        {
            String content = request.getParameter(CoupleUploadPanel.CONTENT);
            T model = deserialize(content);
            UploadResultModel resultModel = upload(model,firstFile,secondFile); // it's implemented in UploadFileServletImpl 
            if(resultModel.hasCriticalError())
            {
                response.getWriter().print(AppConstants.UPLOAD_FAIL + "," + String.valueOf(resultModel.getWorkshopHistoryId()));
            }
            else
            {
                response.getWriter().print(AppConstants.UPLOAD_SUCCESS + "," + String.valueOf(resultModel.getWorkshopHistoryId()));
            }
        }
        catch(ProcessRequestException e)
        {
           // write upload error description in response.getWriter()
        }
        catch(Exception e)
        {
            e.printStackTrace();
            response.getWriter().print(AppConstants.UPLOAD_UNKOWN_ERROR);
        }
    }

    ...
}

我的 app-servlet.xml 中有一个 multipartResolver bean (file.upload.max_size=9437184)，还有一个用于处理 UploadSizeExceededExceptions 的 maxUploadSizeExceededExceptionHandler bean:

 <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
     <property name="maxUploadSize" value="${file.upload.max_size}" />
 </bean>
 <bean id="maxUploadSizeExceededExceptionHandler" class="com.insurance.ui.server.uploadfile.MaxUploadSizeExceededExceptionHandler">
     <property name="order" value="1"/>
 </bean>

我的 maxUploadSizeExceededExceptionHandler:

public class MaxUploadSizeExceededExceptionHandler implements HandlerExceptionResolver, Ordered
{
    private int order;

    @Override
    public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
    {
        if(ex instanceof MaxUploadSizeExceededException)
        {
            try
            {
                response.getWriter().print(ErrorConstants.UPLOAD_SIZE_EXCEED + "," + (((MaxUploadSizeExceededException) ex).getMaxUploadSize()/(1024*1024)));
                response.getWriter().flush();
                response.flushBuffer();
                return new ModelAndView();
            }
            catch(IOException e)
            {
            }
        }
        return null;
    }
    ...
}

当我上传一个非常大的文件(超过 ${file.upload.max_size}，大约 700MB)时，CommonsMultipartResolver 立即抛出 MaxUploadSizeExceededException 我正在捕获并处理它(写入 response.getWriter())。但是 < strong>我的问题:我的浏览器上传进度条显示文件还在上传!!为什么？

更新:我正在使用:

• Spring-*-3.0.5.RELEASE
• commons-fileupload-1.1.1

也试过了:

• Spring-*-3.1.2.RELEASE
• commons-fileupload-1.3

还有我的 AS:

• Tomcat 6(开发中)
• Jboss 7(生产中)

更新 2: 在客户端，我使用的是 GWT(我认为没关系):

点击 submitRequestButton 开始上传:

@UiHandler("submitRequestButton")
public void submitRequestButtonClick(ClickEvent event)
{
    try
    {
        // some validation
        submitRequestButton.setEnabled(false);
        uploadPanel.upload(model.getWorkshopHistoryModel()); // uploadPanel is from the CoupleUploadPanel type
    }
    catch(ValidationException exception)
    {
        // handle validation errors
    }
    catch(SerializationException e)
    {
        // handle serialization errors
    }
}

我有一个 CoupleUploadPanel 小部件用于上传(两个文件):

public class CoupleUploadPanel<T extends Serializable> extends FormPanel
{
    public final static String CONTENT = "content";
    private static final String FIRST_FILE = "firstFile";
    private static final String SECOND_FILE = "secondFile";

    private Hidden contentInput;
    private FileUpload firstFileUploadInput;
    private FileUpload secondFileUploadInput;
    private SerializationStreamFactory factory;

    public CoupleUploadPanel(UploadServletAsync<T> factory)
    {
        this(null,factory);
    }

    public CoupleUploadPanel(String url, UploadServletAsync<T> factory)
    {
        this.factory = (SerializationStreamFactory) factory;
        if(url != null)
        {
            setAction(url);
        }
        init();
    }
    public CoupleUploadPanel(String target, String url, UploadServletAsync<T> factory)
    {
        super(target);
        this.factory = (SerializationStreamFactory) factory;
        if(url != null)
        {
            setAction(url);
        }
        init();
    }

    private void init()
    {
        setMethod("POST");
        setEncoding(ENCODING_MULTIPART);
        firstFileUploadInput = new FileUpload();
        firstFileUploadInput.setName(CoupleUploadPanel.FIRST_FILE);
        secondFileUploadInput = new FileUpload();
        secondFileUploadInput.setName(CoupleUploadPanel.SECOND_FILE);
        contentInput = new Hidden();
        contentInput.setName(CONTENT);
        VerticalPanel panel = new VerticalPanel();
        panel.add(firstFileUploadInput);
        panel.add(secondFileUploadInput);
        panel.add(contentInput);
        add(panel);
    }

    public void upload(T input) throws SerializationException
    {
        contentInput.setValue(serialize(input));
        submit();
    }

    private String serialize(T input) throws SerializationException
    {
        SerializationStreamWriter writer = factory.createStreamWriter();
        writer.writeObject(input);
        return writer.toString();
    }
}

我们应该将 UploadServletAsync 传递给 CoupleUploadPanel 构造函数。 UploadServletAsync 和 UploadServlet 接口(interface):

public interface UploadServletAsync<T extends Serializable> 
{
    void upload(T model, AsyncCallback<Void> callback);
}

public interface UploadServlet<T extends Serializable> extends RemoteService
{
    void upload(T model);
}

所以uploadPanel会以这种方式实例化:

uploadPanel= new CoupleUploadPanel<WorkshopHistoryModel>((UploadFileServletAsync) GWT.create(UploadFileServlet.class));
uploadPanel.setAction(UploadFileServlet.URL);

并且在uploadPanel 中添加了一个SubmitCompeleteHandler(onSumbitComplete() 将在提交完成并将结果传递给客户端时调用):

uploadPanel.addSubmitCompleteHandler(new SubmitCompleteHandler()
{

    @Override
    public void onSubmitComplete(SubmitCompleteEvent event)
    {
        String s = event.getResults(); //contains whatever written by response.getWriter() 
        if(s == null)
        {
            // navigate to request list page
        }
        else
        {
            String[] response = s.split(",");
            // based on response: 
            // show error messages if any error occurred in file upload
            // else: navigate to upload result page
        }
    }
});

UploadFileServlet 和 UploadFileServletAsync 接口(interface):

public interface UploadFileServlet extends UploadServlet<WorkshopHistoryModel>
{
    String URL = "**/uploadFileService.mvc";
}

public interface UploadFileServletAsync extends UploadServletAsync<WorkshopHistoryModel>
{
    public static final UploadFileServletAsync INSTANCE = GWT.create(UploadFileServlet.class);
}

在服务器端:UploadFileServletImpl扩展了AbstractCoupleUploadController并实现了upload()方法(上传过程):

@RequestMapping(UploadFileServlet.URL)
public class UploadFileServletImpl extends AbstractCoupleUploadController<WorkshopHistoryModel>
{
    ...

    @Override
    protected UploadResultModel upload(WorkshopHistoryModel model, MultipartFile firstFile, MultipartFile secondFile)
            throws ProcessRequestException
    {
        return workshopHistoryService.submitList(model.getWorkshop(),firstFile,secondFile);
    }

    ...
}

Answer 1

好吧，afaik Spring(一个 servlet 和一些过滤器)不观察上传过程，而只处理完成过程的结果。这是因为上传是由 Tomcat 自己处理的(提示:web.xml 中有上传大小限制选项)。因此，可能会导致上传失败(Spring 不会注意到)或上传太大的文件。只有当第二次发生时，特定的过滤器/拦截器才能拒绝该过程。

在我上次的设置中，我在 Tomcat 前使用 Nginx 作为代理:

1. 如果您的浏览器发送实际文件大小(现代浏览器会发送，至少 IE7？或 IE8？不会)，如果大小超过定义的限制，Nginx 将发送 500。
2. 我不能 100% 确定:如果上传的大小超过指定的限制，Nginx 也会发送 500。这也会取消与 Tomcat 的底层连接。