使用JFreeChart制作图表，但是鼠标移动屏幕就闪一下，public void update(Graphics g){paint(g)}不能消除求高手指教
import java.awt.*;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.swing.*;

import org.jfree.chart.*;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.time.*;
import org.jfree.data.time.ohlc.OHLCSeries;
import org.jfree.data.time.ohlc.OHLCSeriesCollection;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.*;

public class TimeSeriesDemo1 extends ApplicationFrame implements ChartMouseListener {

  public JFreeChart chart;
  ChartPanel chartPanel;
  private boolean crossedAxis = false;
  private double xValue = 0.0;
  private double yValue = 0.0;
  private int mouseX = 0;
  private int mouseY = 0;
  private Point2D point;
  private Rectangle2D rectangle2D;
  private SimpleDateFormat dateFormat1 = new SimpleDateFormat("yyyy年MM月dd日HH时mm分");
  public static XYPlot xyplot;
  public Frame frame;
  public TimeSeriesDemo1(String s)
  {
  super(s);
  XYDataset xydataset = createDataset();
  JFreeChart jfreechart = createChart(xydataset);
  chartPanel = new ChartPanel(jfreechart, false);
  chartPanel.addChartMouseListener(this);
  chartPanel.setPreferredSize(new Dimension(500, 270));
  chartPanel.setMouseZoomable(true, false);
  chartPanel.setVerticalAxisTrace(true);
  chartPanel.setHorizontalAxisTrace(true);
  setContentPane(chartPanel);
  }

  private static JFreeChart createChart(XYDataset xydataset)
  {
  JFreeChart jfreechart = ChartFactory.createTimeSeriesChart("Legal & General Unit Trust Prices", "Date", "Price Per Unit", xydataset, true, true, true);
  jfreechart.setBackgroundPaint(Color.white);
  xyplot = (XYPlot)jfreechart.getPlot();
  xyplot.setBackgroundPaint(Color.lightGray);
  xyplot.setDomainGridlinePaint(Color.white);
  xyplot.setRangeGridlinePaint(Color.white);
  xyplot.setAxisOffset(new RectangleInsets(5D, 5D, 5D, 5D));
  xyplot.setDomainCrosshairVisible(true);
  xyplot.setRangeCrosshairVisible(true);
  org.jfree.chart.renderer.xy.XYItemRenderer xyitemrenderer = xyplot.getRenderer();
  if(xyitemrenderer instanceof XYLineAndShapeRenderer)
  {
  XYLineAndShapeRenderer xylineandshaperenderer = (XYLineAndShapeRenderer)xyitemrenderer;
  xylineandshaperenderer.setBaseShapesVisible(true);
  xylineandshaperenderer.setBaseShapesFilled(true);
  }
  DateAxis dateaxis = (DateAxis)xyplot.getDomainAxis();
  dateaxis.setDateFormatOverride(new SimpleDateFormat("MMM-yyyy"));
  return jfreechart;
  }

  private static XYDataset createDataset()
  {
  TimeSeries timeseries = new TimeSeries("L&G European Index Trust", org.jfree.data.time.Month.class);
  timeseries.add(new Month(2, 2001), 181.80000000000001D);
  timeseries.add(new Month(3, 2001), 167.30000000000001D);
  timeseries.add(new Month(4, 2001), 153.80000000000001D);
  timeseries.add(new Month(5, 2001), 167.59999999999999D);
  timeseries.add(new Month(6, 2001), 158.80000000000001D);