package com.szf.servlet;
import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.servlet.ServletException;
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.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
public class UploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private static final long FILE_MAX_SIZE = 4 * 1024 * 1024;
public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
if (!ServletFileUpload.isMultipartContent(request)) {
forward(request, response, "error form type");
}
String fileTempPath = this.getServletContext().getRealPath("/") + "filetemp";
File tempDir = new File(fileTempPath);
if (!tempDir.exists()) {
tempDir.mkdirs();
}
FileItemFactory factory = new DiskFileItemFactory(4096, tempDir);
ServletFileUpload sfu = new ServletFileUpload(factory);
sfu.setFileSizeMax(FILE_MAX_SIZE);
List<FileItem> fileItems = null;
try {
fileItems = sfu.parseRequest(request);
} catch (FileUploadException e) {
e.printStackTrace();
if (e instanceof SizeLimitExceededException) {
forward(request, response, "invalid file size");
}
return;
}
if (fileItems == null || fileItems.size() == 0) {
forward(request, response, "please upload a file");
return;
}
this.saveFile(request, response, fileItems);
}
private void forward(HttpServletRequest request, HttpServletResponse response, String message) throws ServletException, IOException {
String url = "/index.jsp";
request.setAttribute("message", message);
request.getRequestDispatcher(url).forward(request, response);
}
private void saveFile(HttpServletRequest request, HttpServletResponse response, List<FileItem> fileItems) throws ServletException, IOException {
for (FileItem fi : fileItems) {
if (fi == null || fi.isFormField()) {
continue;
}
File file = new File("d://"+fi.getName());
try {
fi.write(file);
} catch (Exception e) {
forward(request, response, e.getMessage());
}
}
}
}
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<c:set var="ctx" value="${pageContext.request.contextPath}" scope="page"></c:set>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>upload</title>
</head>
<body>
<c:out value="${message}"></c:out>
<form action="${ctx}/servlet/UploadServlet" method="post" enctype="multipart/form-data">
文件<input type="file" name="file"/><br/>
<input type="submit" value="上传"/>
</form>
</body>
</html>
