java实现动态上传多个文件并解决文件重名问题_JAVA教程

本文分为两大方面进行讲解：

一、java实现动态上传多个文件

二、解决文件重命名问题java

供大家参考，具体内容如下

1、动态上传多个文件

				?

									<form name="xx" action="<c:url value='/Up3Servlet'/>" method="post" enctype="multipart/form-data">

									  <table id="tb" border="1">

									    <tr>

									      <td>

									        File：

									      </td>

									      <td>

									        <input type="file" name="file">

									        <button onclick="_del(this);">删除</button>

									      </td>

									    </tr>

									  </table>

									  <br/>

									  <input type="button" onclick="_submit();" value="上传">

									  <input onclick="_add();" type="button" value="增加">

									  </form>

									 </body>

									 <script type="text/javascript">

									   function _add(){

									     var tb = document.getElementById("tb");

									     //写入一行

									     var tr = tb.insertRow();

									     //写入列

									     var td = tr.insertCell();

									      //写入数据

									     td.innerHTML="File：";

									     //再声明一个新的td

									     var td2 = tr.insertCell();

									     //写入一个input

									     td2.innerHTML='<input type="file" name="file"/><button onclick="_del(this);">删除</button>';

									   }

									   function _del(btn){

									     var tr = btn.parentNode.parentNode;

									     //alert(tr.tagName);

									     //获取tr在table中的下标

									     var index = tr.rowIndex;

									     //删除

									     var tb = document.getElementById("tb");

									     tb.deleteRow(index);

									   }

									   function _submit(){

									     //遍历所的有文件

									     var files = document.getElementsByName("file");

									     if(files.length==0){

									       alert("没有可以上传的文件");

									       return false;

									     }

									     for(var i=0;i<files.length;i++){

									       if(files[i].value==""){

									         alert("第"+(i+1)+"个文件不能为空");

									         return false;

									       }

									     }

									    document.forms['xx'].submit();

									   }

									 </script>

									</html>

遍历所有要上传的文件

2、解决文件的重名的问题

									package cn.hx.servlet;

									import java.io.File;

									import java.io.IOException;

									import java.io.PrintWriter;

									import java.util.ArrayList;

									import java.util.List;

									import java.util.UUID;

									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.disk.DiskFileItemFactory;

									import org.apache.commons.fileupload.servlet.ServletFileUpload;

									import org.apache.commons.io.FileUtils;

									public class UpImgServlet extends HttpServlet {

									  public void doPost(HttpServletRequest request, HttpServletResponse response)

									      throws ServletException, IOException {

									    request.setCharacterEncoding("UTF-8");

									    String path = getServletContext().getRealPath("/up");

									    DiskFileItemFactory disk = 

									        new DiskFileItemFactory(1024*10,new File("d:/a"));

									    ServletFileUpload up = new ServletFileUpload(disk);

									    try{

									      List<FileItem> list = up.parseRequest(request);

									      //只接收图片*.jpg-iamge/jpege.,bmp/imge/bmp,png,

									      List<String> imgs = new ArrayList<String>();

									      for(FileItem file :list){

									        if(file.getContentType().contains("image/")){

									          String fileName = file.getName();

									          fileName = fileName.substring(fileName.lastIndexOf("\\")+1);

									          //获取扩展

									          String extName = fileName.substring(fileName.lastIndexOf("."));//.jpg

									          //UUID

									          String uuid = UUID.randomUUID().toString().replace("-", "");

									          //新名称

									          String newName = uuid+extName;     //在这里用UUID来生成新的文件夹名字，这样就不会导致重名

									          FileUtils.copyInputStreamToFile(file.getInputStream(),

									              new File(path+"/"+newName));

									          //放到list

									          imgs.add(newName);

									        }

									        file.delete();

									      }

									      request.setAttribute("imgs",imgs);

									      request.getRequestDispatcher("/jsps/imgs.jsp").forward(request, response);

									    }catch(Exception e){

									      e.printStackTrace();

									    }

									  }

									}