数据库连接类
package DBConn;
import java.sql.*;
public class DataBaseConn{
String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=student";
String user="sa";
String psw="";
String drivername="com.microsof.jdbc.sqlserver.SQLServerDriver";
ResultSet rs=null;
Statement stmt=null;
Connection conn=null;
public DataBaseConn(){}
public void openconn()throws Exception{
try{
Class.forName(drivername);
conn=DriverManager.getConnection(url,user,psw);
}
catch(Exception e){
System.out.println(e.getMessage());
}
}
public ResultSet executeQuery(String sql){
try{
stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
rs=stmt.executeQuery(sql);
}
catch(SQLException e){
System.err.println("executeQuery:"+e.getMessage());
}
return rs;
}
public void executeUpdate(String sql){
try{
stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
stmt.executeUpdate(sql);
}
catch(Exception e){
System.err.println("executeUpdate:"+e.getMessage());
}
}
public void closeconn(){
try{
conn.close();
}
catch(Exception e){
System.out.println(e);
}
}
public void closestmt(){
try{
stmt.close();
}
catch(Exception e){
System.out.println(e);
}
}
}
jsp
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.sql.*" %>
<jsp:useBean id="db" scope="session" class="DBConn.DataBaseConn">
</jsp:useBean>
<html>
<body>
<table>
<tr>
<%!String sql="select sid from stu";
String s="";
%>
<% db.openconn();
ResultSet rs=db.executeQuery(sql);
while(rs.next()){
s=rs.getString(1);
}
%>
<td><%=s %></td>
</tr>
</table>
</body>
</html>
运行时出现的问题
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 /test.jsp at line 14
11: String s="";
12: %>
13: <% db.openconn();
14: ResultSet rs=db.executeQuery(sql);
15: while(rs.next()){
16: s=rs.getString(1);
17: }
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)