fileuploadservlet.java

数据结构考试 网站（jsp）

package com.dsexam;

import java.io.*;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

public class fileUploadServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

	/**
	 * Destruction of the servlet. <br>
	 */
	public fileUploadServlet() {
		super();
	}

	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		request.setCharacterEncoding("UTF-8");
		HttpSession session = request.getSession(true);
		String snumber = (String) session.getAttribute("snumber");
		String topicnumber = (String) session.getAttribute("topicnumber");

		DiskFileItemFactory factory = new DiskFileItemFactory();
		factory.setSizeThreshold(4096);
		factory.setRepository(new File("c:\\Temp\\"));
		ServletFileUpload upload = new ServletFileUpload(factory);

		FileUpload dfu = new FileUpload();
		upload.setSizeMax(2 * 1024 * 1024);
		dfu.setSizeMax(2 * 1024 * 1024);

		ArrayList  ResultList   =   new   ArrayList();
		
		try {

			List<?> fileitems = upload.parseRequest(request);
			Iterator<?> it = fileitems.iterator();
			final String[] allowedExt = new String[] { "txt", "c", "exe",
					"rar", "doc", "docx" };

			while (it.hasNext()) {
				FileItem fileitem = (FileItem) it.next();
				// 忽略不是文件域的元素.
				if (!fileitem.isFormField()) {
					String name = fileitem.getName();
					long size = fileitem.getSize();
					if ("".equals(name) || size == 0) {
						continue;
					}
					System.out.println(name);

					// 得到去除路径的文件名
					String t_name = name.substring(name.lastIndexOf("\\") + 1);
					// 得到文件的扩展名(无扩展名时将得到全名)
					String t_ext = t_name.substring(t_name.lastIndexOf(".") + 1);
					// 拒绝接受规定文件格式之外的文件类型
					int allowFlag = 0;
					int allowedExtCount = allowedExt.length;
					for (; allowFlag < allowedExtCount; allowFlag++) {
						if (allowedExt[allowFlag].equals(t_ext))
							break;
					}

					String prefix = snumber + "_" + topicnumber + "_" + t_name;
					String u_name = "C:\\Temp\\" + prefix;
					
					try {
						fileitem.write(new File(u_name));
						ResultList.add(prefix);
						ResultList.add(Long.toString(size));
					} catch (Exception e) {
						out.print(e);
					}
					session.setAttribute("ResultList", ResultList);
				} else {
					System.out.println("上传结束!");
				}
				
			}

			response.setContentType("text/html; charset=utf-8");
			response.sendRedirect("save.jsp?snumber="+snumber);
		} catch (Exception e) {
			System.out.println(e.toString());
		}

	}

	/**
	 * The doPost method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to
	 * post.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}

	/**
	 * Initialization of the servlet. <br>
	 * 
	 * @throws ServletException
	 *             if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}