SQLHelper.java package com.pingod.database; import java.sql.SQLException; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.util.*; import com.pingod.sql.ConnectionPool; public final class SQLHelper { private ConnectionPool pool = null; private Connection con = null; private PreparedStatement pstmt = null; private ResultSet rs = null; public SQLHelper(){ pool = ConnectionPool.getInstance(); } public ResultSet userDbQuery() throws SQLException{ con = pool.getConnection(); String sql = "select tempid,username,password from tempuser where 1 = ?"; pstmt = con.prepareStatement(sql); pstmt.setInt(1,1); rs = pstmt.executeQuery(); pstmt.close();//我把这行和下面那行注释掉query.jsp就可以显示了，否则提示[Microsoft][SQLServer JDBC Driver]Object has been closed. con.close(); return rs; } } query.jsp <%@ page contentType="text/html; charset=gb2312"%> <%@ page import="java.util.*, java.sql.*, java.text.*"%> <%@ page import="com.pingod.database.SQLHelper"%> <%! ResultSet rs = null; %> <HTML> <HEAD> <TITLE></TITLE> </HEAD> <BODY leftmargin="5" topmargin="8" bgcolor="FFFFFF" text="#000000"> <table width="100%" border="1" cellspacing="0" cellpadding="0"> <tr> <td>id</td> <td>username</td> <td>password</td> </tr> <% SQLHelper sqlHelper = new SQLHelper(); rs = sqlHelper.userDbQuery(); while(rs.next()){ String id = rs.getString(1); String username = rs.getString(2); String password = rs.getString(3); %> <tr> <td><%=id%></td> <td><%=username%></td> <td><%=password%></td> </tr> <% } %> </table> </BODY> </HTML>
if (connection != null) return connection to Pool <p class="indent">