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>