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 + "/";
%>
















	

		

			

				
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