最近的项目开发中，遇到了一个多文件上传的问题，即在不刷新页面的情况下，上传多个文件至服务器。现总结分享如下：
本文主要采用了基于jsp的ajax，jquery，servlet等技术。
1.upload.jsp
点击上传时，调用对应的fileupload函数，通过ajax将文件异步传送到servlet中处理。注意在文件上载时，所使用的编码类型应当是“multipart/form-data”，它既可以发送文本数据，也支持二进制数据上载。
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"https://www.jb51.net/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <base href="https://www.jb51.net/<%=basePath%>"> <title>Insert title here</title> <script type="text/javascript" src="https://www.jb51.net/js/jquery.js"></script> <script type="text/javascript" src="https://www.jb51.net/js/ajaxfileupload.js"></script> </head> <script language="JavaScript" type="text/javascript"> var buildph=0; var typeph=0; var planph=0; function fileupload1(){ if($("#locationphoto").val()==""){ alert("上传文件不能为空!"); return false; } var file = $("#locationphoto").val(); var pos=file.lastIndexOf("\\"); var fileName=file.substring(pos+1);//获得文件名字 $.ajaxFileUpload({ url:"PictureServlet";, contentType:"multipart/form-data; text/xml;charset=utf-8", secureuri:false, cache: false,//防止缓存 fileElementId:'locationphoto', dataType: 'text/xml', success: function (data) { document.getElementById("locationspan").innerHTML = fileName; alert(fileName); },error: function (data, status, e){ alert("fail"); } } ); } function fileupload2(){ if($("#buildingphoto").val()==""){ alert("上传文件不能为空!"); return false; } var file = $("#buildingphoto").val(); var pos=file.lastIndexOf("\\"); var fileName=file.substring(pos+1); buildph++; $.ajaxFileUpload({ url:"PictureServlet";, contentType:"multipart/form-data; text/xml;charset=utf-8", secureuri:false, cache: false,//防止缓存 fileElementId:'buildingphoto', dataType: 'text/xml', success: function (data) { document.getElementById("buildingspan"+buildph).innerHTML = fileName; alert(fileName); },error: function (data, status, e){ alert("fail"); } } ); } function fileupload3(){ if($("#typePhoto").val()==""){ alert("上传文件不能为空!"); return false; } var file = $("#typePhoto").val(); var pos=file.lastIndexOf("\\"); var fileName=file.substring(pos+1); typeph++; $.ajaxFileUpload({ url:"PictureServlet";, contentType:"multipart/form-data; text/xml;charset=utf-8", secureuri:false, cache: false,//防止缓存 fileElementId:'typePhoto', dataType: 'text/xml', success: function (data) { document.getElementById("typespan"+typeph).innerHTML = fileName; alert(fileName); },error: function (data, status, e){ alert("fail"); } } ); } </script> <body> <form method="post" action=""> <table> <tr> <td colspan="2">楼盘位置图： <span ></span> <input type="file" value="this.val()"/> <input type="button" value="上传"/> </td> </tr> <tr> <td colspan="2">楼盘照片： <span ></span> <span ></span> <span ></span> <span ></span> <input type="file" value="this.val()"/> <input type="button" value="上传"/> </td> </tr> <tr> <td colspan="2">楼盘户型图： <span ></span> <span ></span> <span ></span> <span ></span> <input type="file" value="this.val()"/> <input type="button" value="上传"/> </td> </tr> </table> </form> </body> </html>
2.PictureServlet.java
通过该servlet接受jsp上传的数据流，存储到相应路径，并解析出文件名。
package com.servlet; import java.io.BufferedOutputStream; import java.io.DataOutputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.ServletInputStream; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.realty.base.action.BuildingAction; /** * Servlet implementation class PictureServlet */ @WebServlet("/PictureServlet") public class PictureServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public PictureServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doPost(request,response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.setContentType("text/xml");//是xml response.setHeader("Cache-Control", "no-cache"); response.setCharacterEncoding("UTF-8"); String filepath ="E:/pic/";//文件上传的路径，实际开发中一般用相对路径 String filename = ""; String; ServletInputStream in = request.getInputStream(); byte[] buf = new byte[4048]; int len = in.readLine(buf, 0, buf.length); String f = new String(buf, 0, len - 1); while ((len = in.readLine(buf, 0, buf.length)) != -1) { filename = new String(buf, 0, len,"utf-8");//解决汉字乱码问题 int j = filename.lastIndexOf("\""); int s = filename.indexOf("filename"); name=filename.substring(s+10,j); filename = name;//通过上述处理可以得到上传的文件名 System.out.println("filename="+filename); DataOutputStream fileStream = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(filepath+ filename))); len = in.readLine(buf, 0, buf.length); len = in.readLine(buf, 0, buf.length); while ((len = in.readLine(buf, 0, buf.length)) != -1) { String tempf = new String(buf, 0, len - 1); if (tempf.equals(f) || tempf.equals(f + "--")) { break; } else{ fileStream.write(buf, 0, len); // 写入 } } fileStream.close(); } PrintWriter out=response.getWriter(); String result = filename ; out.print(result); out.close(); in.close(); } }