java 访问数据库公共类

package com.javaweb.mvc;

import java.sql.*;

/**
 * @author 公共数据访问类
 *
 * Statement 和 PreparedStatement之间的关系和区别
 * 关系：PreparedStatement继承自Statement，都是接口
 * 区别：PreparedStatement可以使用占位符，是预编译的，批处理比Statement效率高
 * 注意：Statement执行SQL语句有SQL注入，一般不使用
 *
 */
public class SqlHelper {
    private static String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
    private static String dbURL = "jdbc:sqlserver://mssql-rw-cyp_coopbusiness.vip.test.suixinhuan.com;DatabaseName=CYP_CoopBusiness";
    private static String userName = "sa";
    private static String userPwd = "";

    private static Connection getCoonection()
        {
        Connection conn = null;
        try
        {
            // 加载JDBC驱动
            Class.forName(driverName);
            // 获取连接
            conn = DriverManager.getConnection(dbURL, userName, userPwd);
            return conn;
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * PreparedStatement执行查询操作
     * @param SQL
     * @param args
     * @return
     */
    public static ResultSet executeQuery(String SQL, Object[] args)
    {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try
        {
           conn = getCoonection();
           ps = conn.prepareStatement(SQL);
           // 设置参数
           if (args != null && args.length > ) {
               for (int i = ; i < args.length; i++) {
                   ps.setObject(i + , args[i]);
               }
           }
           rs = ps.executeQuery();
           return rs;
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        finally {
            try {
                if (rs != null)
                    rs.close();
                if (ps != null)
                    ps.close();
                if (conn != null)
                    conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /**
     * PreparedStatement执行增删改操作
     * @param SQL
     * @param args
     * @return
     */
    public static boolean executeUpdate(String SQL, Object[] args)
    {
        Connection conn = null;
        PreparedStatement ps = null;
        try
        {
            conn = getCoonection();
            ps = conn.prepareStatement(SQL);
            // 设置参数
            if (args != null && args.length > ) {
               for (int i = ; i < args.length; i++) {
                   ps.setObject(i + , args[i]);
               }
            }
            int result = ps.executeUpdate();    //返回受影响的行数
            if(result > )
               return true;
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        finally {
            try {
                if (ps != null)
                    ps.close();
                if (conn != null)
                    conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return false;
    }

    /**
     * Statement执行查询操作
     * @param SQL
     * @return
     */
    public static ResultSet executeQuery(String SQL)
    {
        Connection conn = null;
        Statement sm = null;
        ResultSet rs = null;
        try
        {
           conn = getCoonection();
           sm = conn.createStatement();
           rs = sm.executeQuery(SQL);
           return rs;
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        finally {
            try {
                if (rs != null)
                    rs.close();
                if (sm != null)
                    sm.close();
                if (conn != null)
                    conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

    /**
     * Statement执行增删改操作
     * @param SQL
     * @return
     */
    public static boolean executeUpdate(String SQL)
    {
        Connection conn = null;
        Statement sm = null;
        try
        {
            conn = getCoonection();
            sm = conn.createStatement();
            int result = sm.executeUpdate(SQL);    //返回受影响的行数
            if(result > )
               return true;
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        finally {
            try {
                if (sm != null)
                    sm.close();
                if (conn != null)
                    conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return false;
    }
}

下面是调用实例：

package com.javaweb.mvc;

import java.util.ArrayList;
import java.util.List;
import java.sql.*;

/**
 * @author 数据访问类
 *
 */
public class ServiceStationDao {
    /**
     * @return 查询所有服务站
     *
     */
    public List<ServiceStation> getAll() {
        List<ServiceStation> list = new ArrayList<ServiceStation>();
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;

        try {

            // 加载JDBC驱动
            // Class.forName("com.mysql.jdbc.Driver");
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");

            // 连接服务器和数据库
            // String url = "jdbc:mysql://localhost:3306/student?user=root&password=1234";
            String url = "jdbc:sqlserver://mssql-rw-cyp_coopbusiness.vip.test.suixinhuan.com;DatabaseName=CYP_CoopBusiness";
            String user = "Umanager";
            String password = "ASD123asd!1";
            String sql = "SELECT ROW_NUMBER() over(order by CreateDate) as RowNum,* FROM T_TRA_ServiceStation WHERE DeleteTag = 0 AND CityCode = ? ORDER BY CreateDate";
            conn = DriverManager.getConnection(url, user, password);
            ps = conn.prepareStatement(sql);
            ps.setString(, "");
            rs = ps.executeQuery();
            while (rs.next()) {
                int RowNum = rs.getInt();
                String ID = rs.getString();
                String StationName = rs.getString("StationName");
                String CityCode = rs.getString("CityCode");
                String CityName = rs.getString("CityName");
                String StationAddr = rs.getString("StationAddr");
                int IsEnabled = rs.getInt("IsEnabled");
                String Createor = rs.getString("Createor");
                String strCreateDate = rs.getString("CreateDate");
                java.util.Date CreateDate = CommonHelper.strToDateLong(strCreateDate);

                ServiceStation obj = new ServiceStation(RowNum, ID, StationName, CityCode, CityName, StationAddr,
                        IsEnabled, Createor, CreateDate);
                list.add(obj);
            }
        }
        catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        catch (SQLException e) {
            e.printStackTrace();
        }
        finally {
            try {
                if (rs != null)
                    rs.close();
                if (ps != null)
                    ps.close();
                if (conn != null)
                    conn.close();
            }
            catch (SQLException e) {
                e.printStackTrace();
            }
        }
        return list;
    }

    /**
     * @return 新增服务站
     *
     */
    public boolean addServiceStation(ServiceStation obj) {
//        //方式一
//        String SQL = "INSERT INTO dbo.T_TRA_ServiceStation (ID,StationName,CityCode,CityName,StationAddr,Lng,lat,IsEnabled,Createor,DeleteTag,CreateorUser,CreateDate,LastOperName,LastOperUser,LastOperDate)";
//        SQL += " VALUES ('598212333755587533', '"+obj.getStationName()+"', '110100', '北京-北京市', '"+obj.getStationAddr()+"', 116.420574, 40.012993, 0, 'System', 0, 'System', '"+CommonHelper.getStringDate()+"', 'zhouruibj', '周锐北京', '"+CommonHelper.dateToStrLong(obj.getCreateDate())+"')";
//        boolean result = SqlHelper.executeUpdate(SQL);
        //方式二
        String SQL = "INSERT INTO dbo.T_TRA_ServiceStation VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
        Object[] args = new Object[];
        args[] = CommonHelper.getCard() + CommonHelper.getCard();
        args[] = obj.getStationName();
        args[] = "";
        args[] = "北京-北京市";
        args[] = obj.getStationAddr();
        args[] = 116.420574;
        args[] = 40.012993;
        args[] = ;
        args[] = "System";
        args[] = ;
        args[] = "System";
        args[] = CommonHelper.getStringDate();
        args[] = "zhouruibj";
        args[] = "周锐北京";
        args[] = CommonHelper.dateToStrLong(obj.getCreateDate());
        boolean result = SqlHelper.executeUpdate(SQL, args);
        return result;
    }

    /**
     * @return 删除服务站
     *
     */
    public boolean deleteServiceStation(String ID)
    {
        String SQL = "DELETE FROM T_TRA_ServiceStation WHERE ID = ?";
        Object[] args = new Object[];
        args[] = ID;
        boolean result = SqlHelper.executeUpdate(SQL, args);
        return result;
    }
}