本文实现的文件上传也是无页面刷新的，可以说是一种"类似AJAX"方法
开始之前先说两句无关的，其实在ajax出现之前，web应用也可以是无刷新的，那时大多通过IFrame来做到这一点。当然Ajax出现之后，人们一窝蜂地投奔Ajax 的阵营了，，iFrame 就乏人问津了。但是用iFrame来实现无刷新上传文件确实一个很好的选择。
ps：Ajax技术基本上可以说是由google公司带起来的，但少Gmail中上传文件用的还是 IFrame，所以使用IFrame来上传文件是最好的选择。我在这里这里用的技术是jsp，其实asp，php等也是一样可以这么实现的
html：
<html> <body> <form action="/FileUploadServlet" id="form1" name="form1" encType="multipart/form-data" method="post" target="hidden_frame" > <input type="file" id="file" name="file" style="width:450"> <INPUT type="submit" value="上传文件"><span id="msg"></span> <br> <font color="red">支持JPG,JPEG,GIF,BMP,SWF,RMVB,RM,AVI文件的上传</font> <iframe id="hidden_frame"></iframe></form> </body> </html> <script type="text/javascript"> function callback(msg) { document.getElementById("file").outerHTML = document.getElementById("file").outerHTML; document.getElementById("msg").innerHTML = "<font color=red>"+msg+"</font>";} </script>
java 逻辑处理:
package com.partner.servlets;
import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.PrintWriter;import java.util.Date;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;import org.apache.commons.fileupload.util.Streams;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;
import com.partner.core.util.UploadConfigurationRead;
public class FileUploadServlet extends HttpServlet {
private static final long serialVersionUID = 1L; protected final transient Log log = LogFactory.getLog(FileUploadServlet.class);protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}
@SuppressWarnings("unchecked")protected void doPost(HttpServletRequest request, HttpServletResponse response){//文件存放的目录//File tempDirPath =new File(request.getSession().getServletContext().getRealPath("/")+File.separator+"uploads");String path = UploadConfigurationRead.getInstance().getConfigItem("tempPath").trim();File tempDirPath = new File(path);if(!tempDirPath.exists()){tempDirPath.mkdirs();}//创建磁盘文件工厂DiskFileItemFactory fac = new DiskFileItemFactory();//创建servlet文件上传组件ServletFileUpload upload = new ServletFileUpload(fac); upload.setHeaderEncoding("UTF-8");//文件列表List fileList = null; //解析request从而得到前台传过来的文件try { fileList = upload.parseRequest(request); } catch (FileUploadException ex) { ex.printStackTrace(); return; } //保存后的文件名 String imageName = null; //便利从前台得到的文件列表 Iterator<FileItem> it = fileList.iterator(); while(it.hasNext()){ FileItem item = it.next(); //如果不是普通表单域，当做文件域来处理 BufferedInputStream in = null; BufferedOutputStream out = null; if(!item.isFormField()){ imageName = new Date().getTime()+"_"+item.getName(); try {in = new BufferedInputStream(item.getInputStream());out = new BufferedOutputStream( new FileOutputStream(new File(tempDirPath+File.separator+imageName))); Streams.copy(in, out, true);} catch (IOException e) {log.error("文件上传异常:", e);}finally{if(in != null){try {in.close();} catch (IOException e) {log.error("上传文件关闭输入失败",e);}}if(out != null){try {out.close();} catch (IOException e) {log.error("上传文件关闭输出失败",e);}}} } } PrintWriter out = null;try {out = encodehead(request, response);} catch (IOException e) {e.printStackTrace();}//这个地方不能少，否则前台得不到上传的结果
最好的感觉就是你什么都跟我说。
