Connection conn = null;
    Statement sm = null;
    ResultSet rs = null;
try{
    Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
配制数据源为bbs
  conn = DriverManager.getConnection("jdbc:odbc:bbs", "", "");
  sm = conn.createStatement();
String sql = "SELECT * FROM user WHERE user_name='" + username + "'";
记录集在rs里面,你就可以操作数据库了,
rs = sm.executeQuery(sql);
}catch(Exception e){}