import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.util.List; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; @WebServlet ( "/UploadServlet" ) public class UploadServlet extends HttpServlet { private static final long serialVersionUID = 1L; // 上传文件存储目录 private static final String UPLOAD_DIRECTORY = "upload" ; // 上传配置 private static final int MEMORY_THRESHOLD = 1024 * 1024 * 3 ; // 3MB private static final int MAX_FILE_SIZE = 1024 * 1024 * 40 ; // 40MB private static final int MAX_REQUEST_SIZE = 1024 * 1024 * 50 ; // 50MB /** * 上传数据及保存文件 */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 检测是否为多媒体上传 if (!ServletFileUpload.isMultipartContent(request)) { // 如果不是则停止 PrintWriter writer = response.getWriter(); writer.println( "Error: 表单必须包含 enctype=multipart/form-data" ); writer.flush(); return ; } // 配置上传参数 DiskFileItemFactory factory = new DiskFileItemFactory(); // 设置内存临界值 - 超过后将产生临时文件并存储于临时目录中 factory.setSizeThreshold(MEMORY_THRESHOLD); // 设置临时存储目录 factory.setRepository( new File(System.getProperty( "java.io.tmpdir" ))); ServletFileUpload upload = new ServletFileUpload(factory); // 设置最大文件上传值 upload.setFileSizeMax(MAX_FILE_SIZE); // 设置最大请求值 (包含文件和表单数据) upload.setSizeMax(MAX_REQUEST_SIZE); // 构造临时路径来存储上传的文件 // 这个路径相对当前应用的目录 String uploadPath = getServletContext().getRealPath( "./" ) + File.separator + UPLOAD_DIRECTORY; // 如果目录不存在则创建 File uploadDir = new File(uploadPath); if (!uploadDir.exists()) { uploadDir.mkdir(); } try { // 解析请求的内容提取文件数据 @SuppressWarnings ( "unchecked" ) List<FileItem> formItems = upload.parseRequest(request); if (formItems != null && formItems.size() > 0 ) { // 迭代表单数据 for (FileItem item : formItems) { // 处理不在表单中的字段 if (!item.isFormField()) { String fileName = new File(item.getName()).getName(); String filePath = uploadPath + File.separator + fileName; File storeFile = new File(filePath); // 在控制台输出文件的上传路径 System.out.println(filePath); // 保存文件到硬盘 item.write(storeFile); request.setAttribute( "message" , "文件上传成功!" ); } } } } catch (Exception ex) { request.setAttribute( "message" , "错误信息: " + ex.getMessage()); } // 跳转到 message.jsp getServletContext().getRequestDispatcher( "/message.jsp" ).forward( request, response); } } |