Netbeans连接数据库

/*
Netbeans连接数据库  

NetBeans项目的“项目属性”中“库”一栏中。Tab页“编译和运行”中已经加上jdbc的驱动文件
*/
Connection conn = null;//连接数据库的对象  

PreparedStatement pstmt = null;//执行sql对象  

try {  

    try {  

        Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");  

    } catch (ClassNotFoundException ex) {  

        Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);  

    }  

    conn = DriverManager.getConnection("jdbc:sqlserver://localhost:1433;DatabaseName=task", "sa", "sa");  

    String sql = "select * from userInfo where username='" + username + "'and password='" + password + "'";  

    System.out.println(username);  

    System.out.println(password);  

    pstmt = conn.prepareStatement(sql);  

    ResultSet rs = pstmt.executeQuery();  

    if (rs.next()) {  

        System.out.println("登录成功!");  

        //response.setHeader("refresh", "3;URL=userCenter.jsp");//登陆成功跳转到用户中心  

    } else {  

        System.out.println("失败！");  

    }  

} catch (SQLException e) {  

    System.out.print("错误！\n");  

    System.out.println(e);  

}  

//本文出自 “阿凡达” 博客，请务必保留此出处http://shamrock.blog.51cto.com/2079212/702542