HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: An exception occurred processing JSP page /deletexuan.jsp at line 56
53: <%
54: String s="select * from xuan";
55: ResultSet rs=Li.getRs(s);
56: while(rs.next()){
57: out.print("<form action='DelScoreServlet'>");
58: String ss=rs.getString("xname");
59: out.print("<tr><td>"+ss+"</td><td>");
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:505)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
root cause
java.lang.NullPointerException
org.apache.jsp.deletexuan_jsp._jspService(deletexuan_jsp.java:121)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.16 logs.
Apache Tomcat/6.0.16
那rs应该取什么东西啊?
追答看代码,猜测是一个 结果集,从S 也就是 那个sql语句的查询结果
保存形式类似于 List
String s="select * from xuan";
ResultSet rs=Li.getRs(s);
while(rs.next()){
out.print("");
String ss=rs.getString("xname");
out.print(""+ss+"");??
ResultSet rs=Li.getRs(s);
一定返回ResultSet的非null对象吗。
返回的要么是rs要么为空
追答为空,就会出错了。
还可能Li是空对象。
使用前,检查一下
Li是一个类,这个类主要管数据库的删除,修改,查询,添加,但是能出来的功能就只有添加和修改
那个DBHander里面设的rs就是为空,改了是不是就好了?
追答Li.getRs(s);这个方法的代码贴出来看看?
追问public ResultSet getRs(String sql) throws SQLException{
jspInit();
try {
rs=stmt.executeQuery(sql);
return rs;
} catch (Exception e) {
System.out.print(e);
return null;
}
System.out.print(e); 你看下这里有没有打印错误信息。
在这句下面加一句55: ResultSet rs=Li.getRs(s);
if(null!=rs){
while(rs.next()){
out.print("");
String ss=rs.getString("xname");
out.print(""+ss+"");
}
}