<form name="xx" action="<c:url value='/Up3Servlet'/>" method="post" enctype="multjavascript">      function _add(){          var tb = document.getElementById("tb");          //寫(xiě)入一行          var tr = tb.insertRow();          //寫(xiě)入列          var td = tr.insertCell();           //寫(xiě)入數(shù)據(jù)          td.innerHTML="File：";          //再聲明一個(gè)新的td          var td2 = tr.insertCell();          //寫(xiě)入一個(gè)input          td2.innerHTML='<input type="file" name="file"/><button onclick="_del(this);">刪除</button>';      }      function _del(btn){          var tr = btn.parentNode.parentNode;          //alert(tr.tagName);          //獲取tr在table中的下標(biāo)          var index = tr.rowIndex;          //刪除          var tb = document.getElementById("tb");          tb.deleteRow(index);      }      function _submit(){          //遍歷所的有文件          var files = document.getElementsByName("file");          if(files.length==0){              alert("沒(méi)有可以上傳的文件");              return false;          }          for(var i=0;i<files.length;i++){              if(files[i].value==""){                  alert("第"+(i+1)+"個(gè)文件不能為空");                  return false;              }          }        document.forms['xx'].submit();      }  </script></html>

遍歷所有要上傳的文件

解決文件的重名的問(wèn)題

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?qǐng)D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("http://")+1);                                        //獲取擴(kuò)展                    String extName = fileName.substring(fileName.lastIndexOf("."));//.jpg                    //UUID                    String uuid = UUID.randomUUID().toString().replace("-", "");                    //新名稱(chēng)                    String newName = uuid+extName;         //在這里用UUID來(lái)生成新的文件夾名字，這樣就不會(huì)導(dǎo)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();        }        }}