daohelper.java

来自「简单的信息录入系统 大家可以在这个基础上将其完善 是对初学者的有力帮助」· Java 代码 · 共 86 行

package mvcdemo;
import java.sql.*;
import com.sun.rowset.*;
import javax.sql.rowset.CachedRowSet;//断开模式
public class DAOHelper {
    public DAOHelper() {
    }
    public Connection getConn(){
        Connection con = null;
        try {
            Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
            con = DriverManager.getConnection(
                    "jdbc:microsoft:sqlserver://127.0.0.1;DatabaseName=student",
                    "sa", "");
        } catch (SQLException ex) {
            ex.printStackTrace();
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        }
        return con;
    }
    public int nonQuery(String strSQL){
        int result = 0;
        Connection con = null;
        PreparedStatement pst = null;

        try {
            con = getConn();
            pst = con.prepareStatement(strSQL);
            result = pst.executeUpdate();

        } catch (SQLException ex) {
            ex.printStackTrace();
        }finally{
            try {
                if (pst != null) {
                    pst.close();
                    pst = null;
                }
                if (con != null) {
                    con.close();
                    con = null;
                }
            } catch (SQLException ex1) {
                ex1.printStackTrace();
            }
        }
        return result;
    }

    public CachedRowSet query(String strSQL){
        ResultSet rs = null;
        Connection con = null;
        PreparedStatement pst = null;
        CachedRowSet crs = null;
        try {
            con = getConn();
            pst = con.prepareStatement(strSQL);
            rs = pst.executeQuery();
            crs = new CachedRowSetImpl();
            crs.populate(rs);
        } catch (SQLException ex) {
            ex.printStackTrace();
        }finally{
            try {
                if(rs != null){
                    rs.close();
                    rs = null;
                }
                if (pst != null) {
                    pst.close();
                    pst = null;
                }
                if (con != null) {
                    con.close();
                    con = null;
                }
            } catch (SQLException ex1) {
                ex1.printStackTrace();
            }

        }
        return crs;
    }
}