struts2文件上传大小

--struts2中文件上传的二个限制,一个是struts.multipart.maxSize,如果不设置,struts2 的核心包下的default.properties文件里有默认的大小设置struts.multipart.maxSize=2097152,即2M. 这是struts2文件上传的第一道关.

第二道关是inteceptor中的maximumSize. 当真实的文件大小能通过第一道关时.针对不同的action中配置的inteceptor,maximumSize才能发挥相应的拦截作用.

比如struts.multipart.maxSize=50M. actionA中inteceptorA的maximumSize=30M. actionB中inteceptorB的maximumSize=10M.

struts.multipart.maxSize=50M对于inteceptorA,B都会起到第一关的作用.而inteceptorA和inteceptorB可以在通过第一关之后,根据自己的业务定制各自针对拦截器起作用的maximumSize

如果真实的文件>50M. 抛出会抛出the request was rejected because its size (XXXX) exceeds the configured maximum (XXXX)异常，他是不能被国际化的，因为这个信息是commons-fileupload组件抛出的,是不支持国际化这信息.

struts2.2 org.apache.commons.fileupload.FileUploadBase.java中

 /**   * Creates a new instance.   * @param ctx The request context.   * @throws FileUploadException An error occurred while   *   parsing the request.   * @throws IOException An I/O error occurred.   */   FileItemIteratorImpl(RequestContext ctx)           throws FileUploadException, IOException {       if (ctx == null) {           throw new NullPointerException("ctx parameter");       }          String contentType = ctx.getContentType();       if ((null == contentType)               || (!contentType.toLowerCase().startsWith(MULTIPART))) {           throw new InvalidContentTypeException(                   "the request doesn't contain a "                   + MULTIPART_FORM_DATA                   + " or "                   + MULTIPART_MIXED                   + " stream, content type header is "                   + contentType);       }          InputStream input = ctx.getInputStream();          if (sizeMax >= 0) {           int requestSize = ctx.getContentLength();           if (requestSize == -1) {               input = new LimitedInputStream(input, sizeMax) {                   protected void raiseError(long pSizeMax, long pCount)                           throws IOException {                       FileUploadException ex =                           new SizeLimitExceededException(                               "the request was rejected because"                               + " its size (" + pCount                               + ") exceeds the configured maximum"                               + " (" + pSizeMax + ")",                               pCount, pSizeMax);                       throw new FileUploadIOException(ex);                   }               };           } else {   ///问题就在这里////////////////////////////////////               if (sizeMax >= 0 && requestSize > sizeMax) {                   throw new SizeLimitExceededException(                           "the request was rejected because its size ("                           + requestSize                           + ") exceeds the configured maximum ("                           + sizeMax + ")",                           requestSize, sizeMax);               }           }       }          String charEncoding = headerEncoding;       if (charEncoding == null) {           charEncoding = ctx.getCharacterEncoding();       }          boundary = getBoundary(contentType);       if (boundary == null) {           throw new FileUploadException(                   "the request was rejected because "                   + "no multipart boundary was found");       }          notifier = new MultipartStream.ProgressNotifier(listener,               ctx.getContentLength());       multi = new MultipartStream(input, boundary, notifier);       multi.setHeaderEncoding(charEncoding);          skipPreamble = true;       findNextItem();  

如果InteceptorA上传的是40M的真实文件.那么此时拦截器InteceptorA会访问国际化信息:struts.messages.error.file.too.larges对应的值.

当且仅当上传文件<=30M的时候,InteceptorA才会成功上传.

下面是解决struts.multipart.maxSize提示信息不友好的问题.

当超过50M时.commons-fileupload抛出运行时异常,struts2会把这个异常看到是action级别的异常.所以会将异常信息

the request was rejected because its size (XXXX) exceeds the configured maximum (XXXX)写到actionError里面.我们需要做的就是在action里覆盖addActionError方法

    @Override    public void addActionError(String anErrorMessage) {        //改从国际化里取值        if (anErrorMessage                .startsWith("the request was rejected because its size")) {            super.addActionError(getText("struts.multipart.maxSize.limit"));        } else {            super.addActionError(anErrorMessage);        }    }

相应的配置文件

struts.multipart.maxSize.limit=系统上传的文件最大为50M
struts.messages.error.file.too.larges=新广告批量上传的文件最大为5M
struts.messages.error.content.type.not.allowed=上传的文件格式目前仅支持xls格式
struts.messages.error.uploading=上传文件失败
struts.messages.invalid.token=您已经提交了表单，请不要重复提交。
fileupload.filenums.exceed=已经有超过5个文件在运行,请稍候再试
filedownload.rows.exceed=由于您选择的广告组内广告数量太多，请分组下载
accountNotExist=客户不存在
invalidTask=无效的任务

注意,由于inteceptor中途返回,原来页面上输入的其他文本内容也都不见了，也就是说params注入失败。

 

这个是没办法的，因为这个异常是在文件上传之前捕获的，文件未上传，同时params也为注入，所以这时最好重定向到一个jsp文件，提示上传失败，然后重写填写相应信息。

解决办法:最好跳到一个专门显示错误的页.而不要返回操作页.

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注意,拦截器所谓的同名配置覆盖,是重复执行的,比如defaultStack中是包含fileUpload,token的. 如果将<interceptor-ref name="defaultStack" />放到显示定义的拦截器之后,会覆盖显示定义的拦截器.

下面是正确的拦截器顺序:

        <action name="BatchMIADOperation!*" method="{1}"            class="com.*****.***.action.multiidea.batchad.BatchMIADOperationAction">            <interceptor-ref name="defaultStack" />            <interceptor-ref name="fileUpload">                <param name="maximumSize">5242880</param>                <!--                    <param name="allowedTypes">                    application/vnd.ms-excel                    </param>                -->            </interceptor-ref>            <interceptor-ref name="token">                <param name="excludeMethods">                    init,search,updateBatchCpcMatch,batchExportMIAD,downloadWhenError                </param>            </interceptor-ref>            <result name="input">                /WEB-INF/jsp/multiidea/batchad/BatchMIAD.jsp            </result>            <result name="success">                /WEB-INF/jsp/multiidea/batchad/BatchMIAD.jsp            </result>            <result name="invalid.token">                /WEB-INF/jsp/multiidea/batchad/BatchMIAD.jsp            </result>        </action>