这个我有点不是很明白原理，借作api抄抄书上的代码
package servlet; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; 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.DiskFileUpload; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; public class UploadServlet extends HttpServlet { /** * Constructor of the object. */ public UploadServlet() { super(); } /** * Destruction of the servlet. <br> */ public void destroy() { super.destroy(); // Just puts "destroy" string in log // Put your code here } /** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println("<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">"); out.println("<HTML>"); out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>"); out.println(" <BODY>"); out.print(" This is "); out.print(this.getClass()); out.println(", using the GET method"); out.println(" </BODY>"); out.println("</HTML>"); out.flush(); out.close(); } /** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to post. * * @param request the request send by the client to the server * @param response the response send by the server to the client * @throws ServletException if an error occurred * @throws IOException if an error occurred */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=utf-8"); File file1=null,file2=null; String description1=null,description2=null; PrintWriter out = response.getWriter(); DiskFileUpload diskFileUpload=new DiskFileUpload(); try{ List<FileItem> list=diskFileUpload.parseRequest(request); out.println("遍历所有的FileItem...<br/>"); for(FileItem fileItem:list){ if(fileItem.isFormField()){ if("description1".equals(fileItem.getFieldName())){ out.println("遍历到description1...<br/>"); description1=new String(fileItem.getString().getBytes(),"UTF-8"); } if("description2".equals(fileItem.getFieldName())){ out.println("遍历到description2...<br/>"); description1=new String(fileItem.getString().getBytes(),"UTF-8"); } } else{ if("file1".equals(fileItem.getFieldName())){ File remoteFile=new File(new String(fileItem.getName().getBytes(),"UTF-8")); out.println("便利到file1...<br/>"); out.println("客户端文件位置"+remoteFile.getAbsolutePath()+"<br/>"); file1=new File(this.getServletContext().getRealPath("attachment"),remoteFile.getName()); file1.getParentFile().mkdirs(); file1.createNewFile(); InputStream ins=fileItem.getInputStream(); OutputStream ous=new FileOutputStream(file1); try{ byte[]buffer =new byte[1024]; int len=0; for(;(len=ins.read(buffer))>-1;){ ous.write(buffer,0,len); } out.println("已经保存文件"+file1.getAbsolutePath()+"<br/>"); }finally{ ous.close(); ins.close(); } } if("file2".equals(fileItem.getFieldName())){ File remoteFile=new File(new String(fileItem.getName().getBytes(),"UTF-8")); out.println("便利到fil2...<br/>"); out.println("客户端文件位置"+remoteFile.getAbsolutePath()+"<br/>"); file1=new File(this.getServletContext().getRealPath("attachment"),remoteFile.getName()); file1.getParentFile().mkdirs(); file1.createNewFile(); InputStream ins=fileItem.getInputStream(); OutputStream ous=new FileOutputStream(file1); try{ byte[]buffer =new byte[1024]; int len=0; for(;(len=ins.read(buffer))>-1;){ ous.write(buffer,0,len); } out.println("已经保存文件"+file1.getAbsolutePath()+"<br/>"); }finally{ ous.close(); ins.close(); } } } } out.println("request 解析完毕"); }catch(FileUploadException e){} if(file1!=null){ // } } /** * Initialization of the servlet. <br> * * @throws ServletException if an error occurs */ public void init() throws ServletException { // Put your code here } }
<html> <head> <meta charset="UTF-8"/> <title> </title> </head> <body> <form action="servlet/UploadServlet" method="post" enctype="multipart/form-data"> <div align="center"><br/> <fieldset style="80%"> <legend>上传文件</legend><br /> <div class='line'> <div align="left" class='leftDiv'>上传文件一</div> <div align='left' class='rightDiv'> <input type="file" name="file1" class="text"> </div> </div> <div class='line'> <div align="left" class='leftDiv'>上传文件二</div> <div align='left' class='rightDiv'> <input type="file" name="file1" class="text"> </div> </div> <div class='line'> <div align="left" class='leftDiv'>上传文件说明一</div> <div align='left' class='rightDiv'> <input type="text" name="description1" class="text"> </div> </div> <div class='line'> <div align="left" class='leftDiv'>上传文件说二</div> <div align='left' class='rightDiv'> <input type="text" name="description2" class="text"> </div> </div> <div class='line'> <div align="left" class='leftDiv'></div> <div align='left' class='rightDiv'><br /> <input type="submit" value="上传文件" class="button"> </div> </div> </fieldset> </div> </form> </body> </html>