解决commons-fileupload组件无法处理自定义head信息的bug

红太狼 2022-07-14 00:57 61阅读 0赞

**解决commons-fileupload组件无法处理自定义head信息的bug**

**相关阅读：**

1.  [对commons fileupload组件的简单封装][commons fileupload]

2.  [利用Jakarta commons fileupload组件实现多文件上传][Jakarta commons fileupload]

3. [巧妙使用spring对commons fileUpload的包装][spring_commons fileUpload]

Jakarta commons fileupload组件可以处理HTTP请求及响应，很多时候被用来处理文件上传，但是近期发现，当我们自定义文件上传、自己组装mime信息、文件上传时加入自定义head节点时，fileupload组件无法获得自定义的head节点，仔细分析了fileupload组件源代码后，发现核心方法在 FileUploadBase文件的 findNextItem方法中，问题在于fileupload组件解析完自定义的head节点后，却忘记传递到 FileItemStreamImpl中了，稍作修订，即可修正该bug。

/\*\*解析文件列表 \* Called for finding the nex item, if any. \* @return True, if an next item was found, otherwise false. \* @throws IOException An I/O error occurred. \*/ private boolean findNextItem() throws IOException \{ if (eof) \{ return false; \} if (currentItem != null) \{ currentItem.close(); currentItem = null; \} for (;;) \{ boolean nextPart; if (skipPreamble) \{ nextPart = multi.skipPreamble(); \} else \{ nextPart = multi.readBoundary(); \} if (!nextPart) \{ if (currentFieldName == null) \{ // Outer multipart terminated -> No more data eof = true; return false; \} // Inner multipart terminated -> Return to parsing the outer multi.setBoundary(boundary); currentFieldName = null; continue; \} FileItemHeaders headers = getParsedHeaders(multi.readHeaders()); if (currentFieldName == null) \{ // We're parsing the outer multipart String fieldName = getFieldName(headers); if (fieldName != null) \{ String subContentType = headers.getHeader(CONTENT\_TYPE); if (subContentType != null && subContentType.toLowerCase() .startsWith(MULTIPART\_MIXED)) \{ currentFieldName = fieldName; // Multiple files associated with this field name byte\[\] subBoundary = getBoundary(subContentType); multi.setBoundary(subBoundary); skipPreamble = true; continue; \} String fileName = getFileName(headers); currentItem = new FileItemStreamImpl(fileName, fieldName, headers.getHeader(CONTENT\_TYPE), fileName == null, getContentLength(headers)); notifier.noteItem(); itemValid = true; return true; \} \} else \{ String fileName = getFileName(headers); if (fileName != null) \{ //这里代码要修订 //这是原来的代码，没有传入header //currentItem = new FileItemStreamImpl(fileName, currentFieldName,headers.getHeader(CONTENT\_TYPE),false, getContentLength(headers)); //这是新的代码，我们要传入header currentItem = new FileItemStreamImpl(fileName, currentFieldName,headers.getHeader(CONTENT\_TYPE),false, getContentLength(headers),headers); notifier.noteItem(); itemValid = true; return true; \} \} multi.discardBodyData(); \} \} /\*\*原始代码，存在丢失FileItemHeaders信息的bug \* Creates a new instance. \* @param pName The items file name, or null. \* @param pFieldName The items field name. \* @param pContentType The items content type, or null. \* @param pFormField Whether the item is a form field. \* @param pContentLength The items content length, if known, or -1 \* @throws IOException Creating the file item failed. \*/ FileItemStreamImpl(String pName, String pFieldName, String pContentType, boolean pFormField, long pContentLength) throws IOException \{ name = pName; fieldName = pFieldName; contentType = pContentType; formField = pFormField; final ItemInputStream itemStream = multi.newInputStream(); InputStream istream = itemStream; if (fileSizeMax != -1) \{ if (pContentLength != -1 && pContentLength > fileSizeMax) \{ FileUploadException e = new FileSizeLimitExceededException( "The field " + fieldName + " exceeds its maximum permitted " + " size of " + fileSizeMax + " characters.", pContentLength, fileSizeMax); throw new FileUploadIOException(e); \} istream = new LimitedInputStream(istream, fileSizeMax) \{ protected void raiseError(long pSizeMax, long pCount) throws IOException \{ itemStream.close(true); FileUploadException e = new FileSizeLimitExceededException( "The field " + fieldName + " exceeds its maximum permitted " + " size of " + pSizeMax + " characters.", pCount, pSizeMax); throw new FileUploadIOException(e); \} \}; \} stream = istream; \} /\*\*创建FileItem，修订后的代码，解决丢失FileItemHeaders信息的bug \* @param pName \* @param pFieldName \* @param pContentType \* @param pFormField \* @param pContentLength \* @param headers \* @throws IOException \*/ FileItemStreamImpl(String pName, String pFieldName, String pContentType, boolean pFormField, long pContentLength,FileItemHeaders headers) throws IOException \{ name = pName; fieldName = pFieldName; contentType = pContentType; formField = pFormField; if(headers!=null)\{ this.headers = headers; \} final ItemInputStream itemStream = multi.newInputStream(); InputStream istream = itemStream; if (fileSizeMax != -1) \{ if (pContentLength != -1 && pContentLength > fileSizeMax) \{ FileUploadException e = new FileSizeLimitExceededException( "The field " + fieldName + " exceeds its maximum permitted " + " size of " + fileSizeMax + " characters.", pContentLength, fileSizeMax); throw new FileUploadIOException(e); \} istream = new LimitedInputStream(istream, fileSizeMax) \{ protected void raiseError(long pSizeMax, long pCount) throws IOException \{ itemStream.close(true); FileUploadException e = new FileSizeLimitExceededException( "The field " + fieldName + " exceeds its maximum permitted " + " size of " + pSizeMax + " characters.", pCount, pSizeMax); throw new FileUploadIOException(e); \} \}; \} stream = istream; \}

[commons fileupload]: http://blog.csdn.net/hbcui1984/archive/2007/05/29/1629151.aspx
[Jakarta commons fileupload]: http://blog.csdn.net/hbcui1984/archive/2007/05/25/1625754.aspx
[spring_commons fileUpload]: http://blog.csdn.net/hbcui1984/archive/2007/07/10/1684596.aspx