public BufferedImage draw()
{
float maxValue = 0;
float minValue = 0;
long maxColumn = 0;
int gridWidth = 0;
int gridHeight = 0;
int beginWidth = 0 ;
String begindate = "" ;
BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics2D g = (Graphics2D)bufferedImage.getGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, width, height);
g.setColor(Color.gray);
g.drawRect(0, 0, width-1, height-1);
//寫出無數據說明文字
ArrayList tempDoc = new ArrayList();
String hText1 = "查詢無相關數據,請重新選擇查詢條件!";
tempDoc.add(hText1);
//畫出提示文字
g.drawString((String)tempDoc.get(0), width - 375 , 40 + gridHeight);
return bufferedImage;
}