摘要：本文介绍怎么结合servlet,jsp来完成文件的上传
1，需要引入两个jar包
commons-fileupload-1.2.1.jar，commons-io-1.4.jar
2，修改web.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app version="3.0" 3 xmlns="http://java.sun.com/xml/ns/javaee" 4 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 5 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 6 http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> 7 <display-name></display-name> 8 9 10 <servlet> 11 <servlet-name>upload</servlet-name> 12 <servlet-class>UploadServlet</servlet-class> 13 <init-param> 14 <param-name>filePath</param-name> 15 <param-value>store</param-value> 16 </init-param> 17 <init-param> 18 <param-name>tempFilePath</param-name> 19 <param-value>temp</param-value> 20 </init-param> 21 </servlet> 22 <servlet-mapping> 23 24 <servlet-name>upload</servlet-name> 25 <url-pattern>/upload</url-pattern> 26 </servlet-mapping> 27 <welcome-file-list> 28 <welcome-file>index.jsp</welcome-file> 29 </welcome-file-list> 30 </web-app>
3,需要一个html界面来点击上传的文件路径等
1 <html> 2 <head> 3 <title>Upload</title> 4 </head> 5 <body > 6 <form name="uploadForm" method="POST" 7 enctype="MULTIPART/FORM-DATA" 8 action="upload"> 9 <table> 10 <tr> 11 <td><div align="right">User Name:</div></td> 12 <td><input type="text" name="username" size="30"/> </td> 13 </tr> 14 <tr> 15 <td><div align="right">Upload File1:</div></td> 16 <td><input type="file" name="file1" size="30"/> </td> 17 </tr> 18 <tr> 19 <td><div align="right">Upload File2:</div></td> 20 <td><input type="file" name="file2" size="30"/> </td> 21 </tr> 22 <tr> 23 <td><input type="submit" name="submit" value="upload"></td> 24 <td><input type="reset" name="reset" value="reset"></td> 25 </tr> 26 </table> 27 </form> 28 </body> 29 </html>
4，通过servlet来控制文件的上传
1 import java.io.File; 2 import java.io.IOException; 3 import java.io.PrintWriter; 4 import java.util.Iterator; 5 import java.util.List; 6 7 import javax.servlet.ServletConfig; 8 import javax.servlet.ServletException; 9 import javax.servlet.http.HttpServlet; 10 import javax.servlet.http.HttpServletRequest; 11 import javax.servlet.http.HttpServletResponse; 12 13 import org.apache.commons.fileupload.FileItem; 14 import org.apache.commons.fileupload.FileUploadException; 15 import org.apache.commons.fileupload.disk.DiskFileItemFactory; 16 import org.apache.commons.fileupload.servlet.ServletFileUpload; 17 18 19 public class UploadServlet extends HttpServlet{ 20 private String filePath;//存放上传文件的目录 21 private String tempFilePath;//存放临时文件的目录 22 @Override 23 protected void doPost(HttpServletRequest req, HttpServletResponse res) 24 throws ServletException, IOException { 25 res.setContentType("text/plain"); 26 //向客户端发送响应正文 27 PrintWriter outNet=res.getWriter(); 28 //创建一个基于硬盘的FileItem工厂 29 DiskFileItemFactory factory=new DiskFileItemFactory(); 30 //设置向硬盘写数据时所用的缓冲区的大小，此处为4k 31 factory.setSizeThreshold(4*1024); 32 //设置临时目录 33 factory.setRepository(new File(tempFilePath)); 34 //设置一个文件上传处理器 35 ServletFileUpload upload=new ServletFileUpload(factory); 36 //设置允许上传的文件的最大尺寸，此为4m 37 upload.setFileSizeMax(4*1024*1024); 38 try { 39 List items=upload.parseRequest(req); 40 Iterator ite=items.iterator(); 41 while (ite.hasNext()) { 42 FileItem item=(FileItem) ite.next(); 43 if(item.isFormField()){ 44 processFormField(item,outNet); //处理普通的表单域 45 46 }else{ 47 processUploadedFile(item,outNet); //处理上传文件 48 49 } 50 } 51 outNet.close(); 52 53 } catch (FileUploadException e) { 54 throw new RuntimeException(); 55 } 56 } 57 58 private void processUploadedFile(FileItem item, PrintWriter outNet) { 59 String filename=item.getFieldName(); 60 int index=filename.lastIndexOf("\"); 61 filename=filename.substring(index+1,filename.length()); 62 long filesize=item.getSize(); 63 64 if(filename.equals("")&&filesize==0)return; 65 66 File uploadFile=new File(filePath+"/"+filename); 67 68 try { 69 item.write(uploadFile); 70 outNet.print(filename+"is saved."); 71 outNet.print("The size of"+filename+"is"+filesize+" "); 72 } catch (Exception e) { 73 throw new RuntimeException(); 74 } 75 76 } 77 78 private void processFormField(FileItem item, PrintWriter outNet) { 79 String name=item.getFieldName(); 80 String value=item.getString(); 81 outNet.println(name+":"+value+" "); 82 83 } 84 85 @Override 86 public void init(ServletConfig config) throws ServletException { 87 88 super.init(config); 89 filePath=config.getInitParameter("filePath"); 90 tempFilePath=config.getInitParameter("tempFilePath"); 91 filePath=getServletContext().getRealPath("/")+"store"; 92 tempFilePath=getServletContext().getRealPath("/")+"temp"; 93 } 94 }