从上传的Excel文件中将数据存储在数据库中
我有一个处理上传Excel文件的代码，通过读取并将其存储在数据库中。 代码如下，它正在编译，但给出了一个错误。
请参阅下面的代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title></title> <link href="http://fonts.googleapis.com/css?family=Source+Sans+Pro:200,300,400,600,700,900|Quicksand:400,700|Questrial" rel="stylesheet" /> <link href="css/default.css" rel="stylesheet" type="text/css" media="all" /> <link href="css/fonts.css" rel="stylesheet" type="text/css" media="all" /> <%@ page import="java.sql.*" %> <%@ page import="com.oreilly.servlet.*" %> <%@ page import="java.io.*"%> <%@ page import="java.util.*"%> <%@ page import="com.oreilly.servlet.*" %> <%@page import=" org.apache.poi.hssf.usermodel.*"%> <%@ page import ="org.apache.poi.poifs.filesystem.*" %> <%@ page import="org.apache.poi.ss.usermodel.Row" %> <%@ page import ="java.util.Date" %> <%@ page import ="java.io.*" %> </head> <body> <div id="header-wrapper"> <div id="header" class="container"> <div id="logo"> <h1><span class="icon icon-cog"></span><a href="#">MPSTME Exam Portal</a></h1> <div id="menu"> <ul> <li><a href="homepage_teacher.html" accesskey="1" title="">Homepage</a></li> <li><a href="#" accesskey="2" title="">New Teacher</a></li> <li><a href="#" accesskey="3" title="">New Student</a></li> <li class="current_page_item"><a href="admin_timetable.jsp" accesskey="5" title="">Upload Timetable</a></li> <li><a href="index.html" accesskey="6" title="">Logout</a></li> </ul> </div> </div> </div> </div> <div id="page-wrapper"> <div id="page" class="container"> <div class="title"> <h2>Upload Timetable</h2> </div> </div> </div> <div class="wrapper"> <div id="three-column" class="container"> <% MultipartRequest m = new MultipartRequest(request,"/Users/Documents/workspace/exam_portal/WebContent",96163690); out.print("uploaded"); %> <% Class.forName("com.mysql.jdbc.Driver"); Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/examportal","root","mpstme"); %> <% String filename="/Users/hemshah/Documents/workspace/exam_portal/WebContent/timetable.xls"; ArrayList dataHolder = readExcelFile(filename); String sql = "insert into timetable values(?,?,?,?,?,?)"; ps = conn.prepareStatement(sql); int count = 0; ArrayList cellStoreArrayList = null; System.out.println("dataHolder.size() = " + dataHolder.size()); for (int i = 1; i < dataHolder.size(); i++) { System.out.println("dataHolder.size()="+dataHolder.get(i)); cellStoreArrayList = (ArrayList)dataHolder.get(i); ps.setString(1,((HSSFCell)cellStoreArrayList.get(0)).toString()); ps.setString(2,((HSSFCell)cellStoreArrayList.get(1)).toString()); ps.setString(3,((HSSFCell)cellStoreArrayList.get(2)).toString()); ps.setString(4,((HSSFCell)cellStoreArrayList.get(3)).toString()); ps.setString(5,((HSSFCell)cellStoreArrayList.get(4)).toString()); ps.setString(6,((HSSFCell)cellStoreArrayList.get(5)).toString()); count= ps.executeUpdate(); // System.out.print(((HSSFCell)cellStoreArrayList.get(5)).toString() + "\t"); } %> <%! PreparedStatement ps=null; public static ArrayList readExcelFile(String filename) { ArrayList cellArrayListHolder=new ArrayList(); ArrayList cellStoreArrayList=new ArrayList(); ArrayList test = null; try { FileInputStream myInput = new FileInputStream(filename); POIFSFileSystem myFileSystem = new POIFSFileSystem(myInput); HSSFWorkbook myWorkbook = new HSSFWorkbook(myFileSystem); HSSFSheet mySheet = myWorkbook.getSheetAt(0); Iterator rowIter = mySheet.rowIterator(); while (rowIter.hasNext()) { HSSFRow myrow = (HSSFRow) rowIter.next(); Iterator cellIter = myrow.cellIterator(); //ArrayList cellStoreArrayList = new ArrayList(); while(cellIter.hasNext()) { HSSFCell myCell = (HSSFCell) cellIter.next(); cellStoreArrayList.add(myCell); } } } catch(Exception e) { } return cellStoreArrayList; } %> <% if(count>0) { %> Following details from Excel file have been inserted in student table of database <table> <tr> <th>Subject ID</th> <th>Subject Name</th> <th>Faculty</th> <th>Date</th> <th>Time</th> <th>Class</th> </tr> <% for (int i = 1; i < dataHolder.size(); i++) { cellStoreArrayList = (ArrayList) dataHolder.get(i); %> <tr> <td><%=((HSSFCell)cellStoreArrayList.get(0)).toString() %></td> <td><%=((HSSFCell)cellStoreArrayList.get(1)).toString() %></td> <td><%=((HSSFCell)cellStoreArrayList.get(2)).toString() %></td> <td><%=((HSSFCell)cellStoreArrayList.get(3)).toString() %></td> <td><%=((HSSFCell)cellStoreArrayList.get(4)).toString() %></td> <td><%=((HSSFCell)cellStoreArrayList.get(5)).toString() %></td> </tr> <%} }%> </table> </div> </body> </html> 这里是错误的堆栈跟踪：
org.apache.jasper.JasperException: An exception occurred processing JSP page /admin_timetable_upload.jsp at line 80 77: for (int i=1;i < dataHolder.size(); i++) 78: { 79: System.out.println("dataHolder.size()="+dataHolder.get(i)); 80: cellStoreArrayList=(ArrayList)dataHolder.get(i); 81: ps.setString(1,((HSSFCell)cellStoreArrayList.get(0)).toString()); 82: ps.setString(2,((HSSFCell)cellStoreArrayList.get(1)).toString()); 83: ps.setString(3,((HSSFCell)cellStoreArrayList.get(2)).toString()); Stacktrace: org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:575) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:477) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) javax.servlet.http.HttpServlet.service(HttpServlet.java:731) root cause java.lang.ClassCastException: org.apache.poi.hssf.usermodel.HSSFCell cannot be cast to java.util.ArrayList org.apache.jsp.admin_005ftimetable_005fupload_jsp._jspService(admin_005ftimetable_005fupload_jsp.java:199) org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) javax.servlet.http.HttpServlet.service(HttpServlet.java:731) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339) javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
我如何解决这个问题？
你不需要这个：
cellStoreArrayList = (ArrayList) dataHolder.get(i);
到一个ArrayList中，它已经返回一个HSSFCell，所以你只需要：
HSSFCell cell = dataHolder.get(i);