servlet上传文件

package fileupload;

import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Iterator;
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.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
*
*
* @author huahua
*/
public class FileUploaded extends HttpServlet {
private String uploadPath = "E:\\"; // 定义文件的上传路径
private int MAXFILESIZE = 100 * 1024 * 1024; // 限制文件的上传大小

public FileUploaded() {
super();
}
public void destroy() {
super.destroy();
}

// 主处理
protected void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
System.out.println("Access !");
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();

// 保存文件到服务器中 |Create a factory for disk-based file items
DiskFileItemFactory factory = new DiskFileItemFactory();
factory.setSizeThreshold(4096); // 超出这个大小放磁盘，否则放在内存中
ServletFileUpload upload = new ServletFileUpload(factory); // Create a new file upload handler
upload.setSizeMax(MAXFILESIZE);
try {
List fileItems = upload.parseRequest(request); // Parse the request,have a List of file items that you need to process
Iterator iter = fileItems.iterator();
while (iter.hasNext()) {
FileItem item = (FileItem) iter.next();
// 如果item.isFormField为true,则代表简单域，否则为file域。Field有2种，一种是简单域，一种是file域。
if (!item.isFormField()) {
// 获得文件名，包括文件的扩展名
String name = item.getName();
System.out.println(name);
try {
// "factory.setRepository(new File(path));"可以设置临时目录
item.write(new File(uploadPath + name)); // 写入磁盘。
} catch (Exception e) {
e.printStackTrace();
}
}
}
} catch (FileUploadException e) {
e.printStackTrace();
System.out.println(e.getMessage() + "结束");
}
}

/**
* Handles the HTTP <code>GET</code> method.
*
* @param request
*            servlet请求
* @param response
*            servlet响应
*/
// 如果是GET请求，则调用doGet方法。
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}

/**
* Handles the HTTP <code>POST</code> method.
*
* @param request
*            servlet请求
* @param response
*            servlet响应
*/
// 如果是POST请求，则调用doPost方法
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}

/**
* Returns a short description of the servlet.
*/
public String getServletInfo() {
return "ServletName: FileUploaded. extends: HttpServlet.";
}
}