package com.test;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class DBConn {        public static Connection getConn(String db){        String driverName="";        String dbURL="";        String userName = "";          String userPwd = "";         if(db.equals("sqlServer")){            driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";            dbURL = "jdbc:sqlserver://192.168.0.1:1444; DatabaseName=test";            userName = "";            userPwd = "";        }else if(db.equals("oracle")){            driverName = "oracle.jdbc.driver.OracleDriver";            dbURL = "jdbc:oracle:thin:@192.168.0.1:1521:test";            userName = "";            userPwd = "";        }else if(db.equals("mysql")){            driverName = "com.mysql.jdbc.Driver";            dbURL = "jdbc:mysql://192.168.0.1:3306/test";            userName = "";            userPwd = "";         }        Connection dbConn=null;        try {            Class.forName(driverName);            dbConn = DriverManager.getConnection(dbURL, userName, userPwd);        } catch (Exception e) {            e.printStackTrace();        }        return dbConn;    }        public static void main(String[] args) {        Connection dbConn =DBConn.getConn("oracle");        System.out.println(dbConn);        String sql = "select id from table";        PreparedStatement ps;        try {            ps = dbConn.prepareStatement(sql);            ResultSet rs = ps.executeQuery();            while(rs.next())                System.out.println(rs.getInt("id"));        } catch (SQLException e) {            e.printStackTrace();        }    }}