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>删除</button> </td> </tr> </table> <br/> <input type="button" value="上传"> <input 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>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(); } } }

以上实现了java多文件上传，解决了文件重名问题，希望对大家的学习有所帮助。