DWR + Servlet 实现文件上传功能

package com.blue.servlet; import java.io.BufferedInputStream; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import javax.servlet.RequestDispatcher; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileItemStream; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.fileupload.util.Streams; import com.blue.beans.ProgressInfo; import com.blue.util.UploadListener; import com.blue.util.Util; public class FileUploadServlet extends HttpServlet { private static final long serialVersionUID = 1L; private static final String FILE_UPLOAD_JSP = "FileUploadForm.jsp"; private static final String SUCCESS_JSP = "success.jsp"; private static final String INDEX = "index.jsp"; private static final String NEXT_SERVLET = "NextServlet"; private static final String PROGRESS_INFO = "PROGRESS_INFO"; private static final long MAX_LENGTH = 10 * 1024 * 1024L; // 10MB private static final int HTTP_REDUNDANT_LENGTH = 1024; // 1KB protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.getSession().removeAttribute(PROGRESS_INFO); RequestDispatcher rd = request.getRequestDispatcher(FILE_UPLOAD_JSP); rd.forward(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Util.info("FileUploadServlet", "posting"); ProgressInfo pi = new ProgressInfo(); request.getSession().setAttribute(PROGRESS_INFO, pi); try { this.doUpload(request, pi); } catch (Exception e) { pi.setInProgress(false); Util.info("FileUploadServlet", "cancelled or interrupted!"); e.printStackTrace(); throw new ServletException(e); } // RequestDispatcher rd = request.getRequestDispatcher(NEXT_SERVLET); RequestDispatcher rd = request.getRequestDispatcher(FILE_UPLOAD_JSP); rd.forward(request, response); } private String getFileName(String fileName) { String name = fileName.substring(fileName.lastIndexOf("\\") + 1); return System.getProperty("java.io.tmpdir") + "/" + name; } private void doUpload(HttpServletRequest request, ProgressInfo pi) throws Exception { String fldName = ""; FileItemStream item = null; BufferedInputStream stream = null; boolean isMultipart = ServletFileUpload.isMultipartContent(request); if (isMultipart) { int filesSize = request.getContentLength() - HTTP_REDUNDANT_LENGTH; if (filesSize >= MAX_LENGTH) { String errorMsg = "Error: Current files size is " + filesSize / (1024 * 1024) + "MB which has exceeded max " + "10MB"; pi.setCompleted(true); pi.setErrorMsg(errorMsg); throw new Exception(errorMsg); } ServletFileUpload upload = new ServletFileUpload(); upload.setFileSizeMax(MAX_LENGTH); upload.setSizeMax(MAX_LENGTH); UploadListener uploadListener = new UploadListener(pi); upload.setProgressListener(uploadListener); // Parse the request FileItemIterator fIter = upload.getItemIterator(request); long curTotalLength = 0L; while (fIter.hasNext()) { item = fIter.next(); fldName = item.getFieldName(); Util.info("FileUploadServlet", fldName + ", " + item.isFormField() + ", " + item.getContentType() + ", " + item.getName() + ", " + item.getHeaders()); if (!item.isFormField()) { fldName = item.getFieldName(); if (item.getName() == null || "".equals(item.getName().trim())) { continue; } stream = new BufferedInputStream(item.openStream()); ByteArrayOutputStream bStream = new ByteArrayOutputStream(); long bStreamLen = Streams.copy(stream, bStream, true); // Util.info("++++++++bStreamLen >> " + bStreamLen); curTotalLength = curTotalLength + bStreamLen; pi.setCurFileName(item.getName()); pi.setUploadedFiles(pi.getUploadedFiles() + "<b>" + item.getName() + " (" + bStreamLen / 1024 + "KB)</b><br/>"); Util.info("FileUploadServlet", this.getFileName(item .getName())); File file = new File(this.getFileName(item.getName())); if (file.exists()) { file.delete(); } OutputStream out = new FileOutputStream(file); bStream.writeTo(out); Util.info("FileUploadServlet", fldName + " just was uploaded, len " + bStreamLen); } } // pi.setTotalSize(curTotalLength/1024); } } }