dbconn.java

一个用Jsp+javaBean+sevlet写的购物车

package hello;
/* 
 * Source File Name: DBconn.java
 * Description: 数据库常用操作 
 * Copyright: ShenZhen szpt Copyright (c) 2005
 * @author 张霞
 */
import java.sql.*;

public class DBconn
{
  	Connection con = null;
  	ResultSet rs = null;
  	
  	String DBDriver="sun.jdbc.odbc.JdbcOdbcDriver";
  	String Connstr="jdbc:odbc:info";
  	String username="";
  	String password="";

  //-------------------------- 构造器：数据库驱动 ---------------------------
    public DBconn()
    {
        try
         {Class.forName(DBDriver);
          }catch(ClassNotFoundException e) {
            System.err.println("DBconn: classnotfoundexception ");
        }
   }
  //----------------------------- get方法 -----------------------------------
   public void setcon(Connection newcon)
   {
     con=newcon;
   }
   public Connection getcon()
    {
      try {
        con = DriverManager.getConnection(Connstr,username,password);
      }
      catch (SQLException e)
        {
            System.err.println("executeQuery: " + e.getMessage());
        }
      return con;
    }
  //----------------------------- set方法 -----------------------------------
   public void setrs(ResultSet newrs)
   {
     rs=newrs;
   }
   public ResultSet getrs()
    {      
      return rs;
    }    
    //------------------------- 数据库添加 -----------------------------------
     public void executeInsert(String s)
     {
         int i = 0;
         Statement sql;

         try
         {
             con = DriverManager.getConnection(Connstr,username,password);
             sql = con.createStatement();
             i = sql.executeUpdate(s);
         }
         catch(SQLException sqlexception)
         {
             System.err.println("executeInsert:" + sqlexception.getMessage());
         }
     }
    //--------------------------- 数据库简单查询 ------------------------------
    public ResultSet Querysimple(String s)
    {
        rs = null;
        Statement sql;
        try
        {
            con = DriverManager.getConnection(Connstr,username,password);
            sql = con.createStatement();
            rs = sql.executeQuery(s);
        }
        catch(SQLException sqlexception)
        {
            System.err.println("executeQuery: " + sqlexception.getMessage());
        }
        return rs;
    }
    //----------------------------- 数据库查询 -------------------------------
    public ResultSet executeQuery(String s)
    {
        rs = null;
        Statement sql;
        try
        {
            con = DriverManager.getConnection(Connstr,username,password);
            sql = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
            rs = sql.executeQuery(s);
        }
        catch(SQLException sqlexception)
        {
            System.err.println("executeQuery: " + sqlexception.getMessage());
        }
        return rs;
    }
    //------------------------------ 数据删除 -------------------------------
    public void executeDelete(String s)
    {
        Statement sql;
        try
        {
            con = DriverManager.getConnection(Connstr,username,password);
            sql = con.createStatement();
            sql.executeUpdate(s);
        }
        catch(SQLException sqlexception)
        {
            System.err.println("executeDelete: " + sqlexception.getMessage());
        }
    }
    //------------------------------ 数据库更新 -------------------------------
    public int executeUpdate(String s)
    {
        int i = 0;
        Statement sql;
        try
        {
            con = DriverManager.getConnection(Connstr,username,password);
            sql = con.createStatement();
            i = sql.executeUpdate(s);
        }
        catch(SQLException sqlexception)
        {
            System.err.println("executeUpdate: " + sqlexception.getMessage());
        }
        return i;
    }
  //-------------------------------- 数据库关闭 --------------------------------
    public void Close()
    {
        try
        {
            if(rs != null)
                rs.close();

            if(con != null)
                con.close();
        }
        catch(SQLException sqlexception)
        {
            System.err.println("close: " + sqlexception.getMessage());
        }
    }
  //------------------------------------------------------------------------------
}