java + ajax 實現進度條文件上傳

package com.cnblogs.zxub.upload; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.ResourceBundle; import javax.servlet.http.HttpServletRequest; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileItemFactory; import org.apache.commons.fileupload.FileUpload; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.MultipartStream; import org.apache.commons.fileupload.servlet.ServletRequestContext; /** * @author zxub 2006-7-14 下午05:25:10 处理输入流，并提供相应信息 */ public class HttpFileUpload extends FileUpload { // 有默认参数文件 public static ResourceBundle config = ResourceBundle.getBundle("config"); private static final long K = 1024 * 1024 * 2; private static final long M = 1024 * 1024 * 1024; // 默认的单个文件大小限制，0为无限制，配置文件中存放的为String类型 private long fileLimitSize = getByteSize(config.getString("fileLimitSize")); // 默认的文件上传类型限制 private String allowFileTypes = config.getString("allowFileTypes"); private String allowFiles = null; // 允许上传的文件类型，null表示无限制 private boolean allowField = true; // 是否允许处理非文件域，默认为否 private int reportLimitSize = 1024000; // 最小报告长度，默认为10K private StreamReport streamReport = null; // 上传进度处理对象 public HttpFileUpload() { super(); setSizeMax(getByteSize(config.getString("onceMaxSize"))); } public HttpFileUpload(FileItemFactory fileItemFactory) { super(fileItemFactory); setSizeMax(getByteSize(config.getString("onceMaxSize"))); } public long getFileLimitSize() { return fileLimitSize; } public void setFileLimitSize(long fileLimitSize) { this.fileLimitSize = fileLimitSize; } public static long getByteSize(String size) { String unit = size.substring(size.length() - 1).toUpperCase(); String num; if (unit.equals("K")) { num = size.substring(0, size.length() - 1); return Long.parseLong(num) * HttpFileUpload.K; } else if (unit.equals("M")) { num = size.substring(0, size.length() - 1); return Long.parseLong(num) * HttpFileUpload.M; } else { return Long.parseLong(size); } } /** * @return [String] 允许上传的文件类型 */ public String getAllowFileTypes() { return allowFileTypes; } /** * 设置允许上传的文件类型，默认是""，无限制 * * @param allowFileTypes */ public void setAllowFileTypes(String allowFileTypes) { this.allowFileTypes = allowFileTypes; } public void addAllowFileTypes(String allowFileTypes) { this.allowFileTypes += ("," + allowFileTypes); } /** * 设置是否允许上载除file以外的field的内容 * * @param allow */ public void setAllowField(boolean allow) { allowField = allow; } /** * @return [boolean] 是否允许上载除file以外的field */ public boolean isAllowField() { return allowField; } /** * 设置最小报告长度，这个参数影响报告频度，默认是10K * * @param reportLimitSize */ public void setReportLimitSize(int reportLimitSize) { this.reportLimitSize = reportLimitSize; } public int getReportLimitSize() { return reportLimitSize; } /** * 上传后清理工作 */ public void dispose() { if (streamReport != null) streamReport.dispose(); } /** * 完成上传操作 根据allowField值决定是否接收除file以外的其它field，并检查上传的文件是否为允许的文件 * * @param request * @return * @throws FileUploadException * @throws IOException */ public List parseRequest(HttpServletRequest request) throws FileUploadException { ServletRequestContext ctx = new ServletRequestContext(request); if (ctx == null) { throw new NullPointerException( "HttpFileUpload(parseRequestEx): ctx parameter"); } ArrayList items = new ArrayList(); String contentType = ctx.getContentType(); if ((null == contentType) || (!contentType.toLowerCase().startsWith(MULTIPART))) { throw new InvalidContentTypeException( "HttpFileUpload(parseRequestEx): the request doesn't contain a " + MULTIPART_FORM_DATA + " or " + MULTIPART_MIXED + " stream, content type header is " + contentType); } int requestSize = ctx.getContentLength(); if (requestSize == -1) { throw new UnknownSizeException("由于数据大小未知，上传被终止！"); } long sizeMax = getSizeMax(); if (sizeMax >= 0 && requestSize > sizeMax) { throw new SizeLimitExceededException("由于文件总大小 [ " + requestSize + " ] 超出限定 [ " + sizeMax + " ],上传被终止！", requestSize, sizeMax); } String charEncoding = getHeaderEncoding(); if (charEncoding == null) { charEncoding = ctx.getCharacterEncoding(); } try { byte[] boundary = getBoundary(contentType); if (boundary == null) { throw new FileUploadException( "the request was rejected because " + "no multipart boundary was found"); } streamReport = new StreamReport(request); streamReport.init(); streamReport.setReportLimitSize(reportLimitSize); InputStream input = ctx.getInputStream(); InputSteamEx inputEx = new InputSteamEx(input, streamReport); MultipartStream multi = new MultipartStream(inputEx, boundary); multi.setHeaderEncoding(charEncoding); boolean nextPart = multi.skipPreamble(); List invalidFiles = new ArrayList(); while (nextPart) { Map headers = parseHeaders(multi.readHeaders()); String fieldName = getFieldName(headers); if (fieldName != null) { String subContentType = getHeader(headers, CONTENT_TYPE); if (subContentType != null && subContentType.toLowerCase().startsWith( MULTIPART_MIXED)) { // Multiple files. // 由于一般传送文件时，设置的是multipart/form-data，所以这里不会进入 byte[] subBoundary = getBoundary(subContentType); multi.setBoundary(subBoundary); boolean nextSubPart = multi.skipPreamble(); while (nextSubPart) { headers = parseHeaders(multi.readHeaders()); if (getFileName(headers) != null) { FileItem item = createItem(headers, false); OutputStream os = item.getOutputStream(); try { multi.readBodyData(os); } finally {