一些可能用得下的

?

1. ChartPanel:
   

   public ChartEntity getEntityForPoint(int viewX,  int viewY)
   Returns the chart entity at a given point.
   This method will return null if there is (a) no entity at the given point, or (b) no entity collection has been generated.
   Parameters:
   viewX - the x-coordinate.
   viewY - the y-coordinate.
   Returns:
   The chart entity (possibly null).

   ?