这是我jsp中的代码:
<%
int cardidint =Integer.valueOf(request.getParameter("cardid"));
System.out.print("卡号 为:"+cardidint);
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
Connection conn = DriverManager.getConnection(
"jdbc:sqlserver://localhost:1433;DatabaseName=eatery;user=sa;password=sasa;");
Statement stmt = conn.createStatement();
String sql="select cardID,name,balance from card where cardID='"+cardidint+"'";
System.out.print("卡号验证成功");
ResultSet rs=stmt.executeQuery(sql);
if(rs.next()){
session.setAttribute("cardid",cardidint);
System.out.println("session中的cardid:"+cardidint);
运行结果(部分):
卡号 为:2230卡号验证成功实数i=4卡号 为:2555卡号验证成功session中的cardid:2555
2011-5-27 20:41:01 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.NumberFormatException: null
at java.lang.Integer.parseInt(Integer.java:417)
at java.lang.Integer.valueOf(Integer.java:554)
at org.apache.jsp.Checkcard_jsp._jspService(Checkcard_jsp.java:98)
这是前一个JSP页面中的HTML代码
<th width="276" scope="col"><form name="cardidform" method="post" onSubmit="return Checkcard()"action="Checkcard.jsp">
<p>
<label><span class="STYLE1">卡号 </span>
<input type="text" name="cardid" width="180" height="35">
</label>
</p>
<p> </p>
<p> </p>
<p>
<input name="Submit" type="Submit" class="STYLE1" value="确定">
</p>