Java implementation dynamically uploads multiple files and resolves file name problems (GO)

This article is divided into two major areas to explain:

One, Java implementation dynamically upload multiple files

Second, solve the problem of file renaming Java

For your reference, the specific contents are as follows

1. Uploading multiple files dynamically

<script>

< 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>

Traverse all the files to be uploaded

2. Solve the problem of duplicate file name

  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();      }       } }The above implementation of the Java multi-file upload, solve the problem of duplicate file name, I hope that everyone's learning has helped.

Java implementation dynamically uploads multiple files and resolves file name problems (GO)