JavaWeb 实现文件上传下载(笔记)

只能说全是坑…………


UpdateServlet.java

public class UpdateServlet extends HttpServlet {
	private static final long serialVersionUID = 1939130975393034262L;

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		try {
			request.setCharacterEncoding("utf-8");
			response.setContentType("text/html;charset=utf-8");
			DiskFileItemFactory factory = new DiskFileItemFactory();
			File f = new File("D:\\Temp");
			if (f.exists()) {
				f.mkdir();
			}
			factory.setRepository(f);
			ServletFileUpload fileUpload = new ServletFileUpload(factory);
			fileUpload.setHeaderEncoding("utf-8");
			List filList = fileUpload.parseRequest(request);
			PrintWriter writer = response.getWriter();
			for (FileItem item : filList) {
				if (item.isFormField()) {
					String name = item.getFieldName();
					if (name.equals("name")) {
						if (!item.getString().equals("")) {
							String value = item.getString("utf-8");
							writer.print("上传者" + value + "
"); } } } else { String filename = item.getName(); if (filename != null && !filename.equals("")) { writer.print("上传的文件名称是:" + filename + "
"); filename = filename.substring(filename .lastIndexOf("\\") + 1); filename = filename.replace(" ", "_"); filename = UUID.randomUUID().toString() + "_blog635_" + filename; String webpath = "/upload/"; String filepath = getServletContext().getRealPath( webpath + filename); File file = new File(filepath); file.getParentFile().mkdir(); file.createNewFile(); InputStream in = item.getInputStream(); FileOutputStream out = new FileOutputStream(file); byte[] buffer = new byte[1024]; int len; while ((len = in.read(buffer)) > 0) out.write(buffer, 0, len); in.close(); out.close(); item.delete(); writer.print("上传文件成功!
"); } } } } catch (FileUploadException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }

DownLoadServlet.java


public class DownLoadServlet extends HttpServlet {
	private static final long serialVersionUID = -6443548568234690815L;

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		response.setCharacterEncoding("utf-8");
		String x = request.getParameter("x");
		String y = request.getParameter("y");
		String aaa = "blog635";
		String xz = x + "_" + aaa + "_" + y;
		xz = new String(xz.getBytes("ISO8859-1"), "utf-8");
		// 通知浏览器以下载方式打开
		response.addHeader("Content-Type", "applicaion/octet-stream");
		response.addHeader("Content-Disposition",
				"attachment;filename=" + xz.substring(45));
		// 通过文件流读取文件
		InputStream in = getServletContext().getResourceAsStream(
				"/upload/" + xz);
		// 获取response对象的输出流
		OutputStream out = response.getOutputStream();
		byte[] buffer = new byte[1024];
		int len;
		while ((len = in.read(buffer)) != -1) {
			out.write(buffer, 0, len);
		}
		in.close();
		out.close();
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}
}

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="java.io.*"%>
<%
	String path = request.getContextPath();
	String basePath = request.getScheme() + "://"
			+ request.getServerName() + ":" + request.getServerPort()
			+ path + "/";
%>





My JSP 'index.jsp' starting page










	

上传者


上传文件


<% String path1 = request.getRealPath("/upload/"); File dir = new File(path1); File file[] = dir.listFiles(); for (int i = 0; i < file.length; i++) { File fs = file[i]; if (fs.isDirectory()) { out.println(fs.getName() + " [目录]
"); } else { out.println("
  • " + "" + fs.getName().substring(45) + "
  • " + "
    "); } } %>

       // 可实现多文件上传

    commons-io-2.6下载地址: https://mirrors.tuna.tsinghua.edu.cn/apache//commons/io/binaries/commons-io-2.6-bin.zip


    commons-fileupload-1.3.3-bin下载地址:http://mirrors.hust.edu.cn/apache//commons/fileupload/binaries/commons-fileupload-1.3.3-bin.zip


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