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

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

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1. 对commons fileupload组件的简单封装

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3. 巧妙使用spring对commons fileUpload的包装

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; }