jdbc连接数据库（mysql，sqlserver，oracle）

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();
        }
    }
}