public class ConData{    private String driverName="com.microsoft.sqlserver.jdbc.SQLServerDriver";    private String dbURL="jdbc:sqlserver://localhost:1433;DatabaseName=testData";    private String userName;//="sa"    private String userPwd;//="199369265"    private Vector<Point> data=http://www.mamicode.com/new Vector<Point>();    private Connection dbConn;        public ConData(String username,String password){        userName=username;        userPwd=password;            }    public void Treat() throws IOException     {        try{            Class.forName(driverName);            dbConn=DriverManager.getConnection(dbURL,userName,userPwd);                      JOptionPane.showMessageDialog(null, "连接数据库成功");                                Statement state=dbConn.createStatement();               ResultSet rs=state.executeQuery("select * from houst_data");            int R=6370856;            int cnt=0;            while(rs.next()){                String name=rs.getString(1);                double x=rs.getDouble(3);//可以采用列号，也可以采用列名，如"X"                double y=rs.getDouble(4);                int price=rs.getInt(5);                                data.addElement(new Point(name,x,y,price,cnt));                    cnt++;            }        }        catch(Exception e){            e.printStackTrace();            System.out.print("连接失败!");        }                         }}