[英]How to add data into a JFree XY chart every 5 seconds?
我可以訪問一個數據庫,該數據庫每5秒返回一個位置的溫度和該位置的時間。
我有一個在x軸上繪制時間的想法。
也許通過使用Java swing Timer,我將能夠每5秒將數據添加到圖形中。
但是,我不知道如何實現它,因為我考慮在createDataset()中添加一個計時器,但是由於它返回了一個數據集,所以我將無法實現它。
知道如何每5秒將數據添加到圖形中嗎?
這是我的代碼:
import java.awt.Color;
import java.awt.BasicStroke;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.data.xy.XYDataset;
import org.jfree.data.xy.XYSeries;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.xy.XYSeriesCollection;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
public class XYLineChart_AWT extends ApplicationFrame {
public XYLineChart_AWT( String applicationTitle, String chartTitle ) {
super(applicationTitle);
JFreeChart xylineChart = ChartFactory.createXYLineChart(
chartTitle ,
"Time" ,
"Temperature" ,
createDataset() ,
PlotOrientation.VERTICAL ,
true , true , false);
ChartPanel chartPanel = new ChartPanel( xylineChart );
chartPanel.setPreferredSize( new java.awt.Dimension( 560 , 367 ) );
final XYPlot plot = xylineChart.getXYPlot( );
XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer( );
renderer.setSeriesPaint( 0 , Color.RED );
renderer.setSeriesStroke( 0 , new BasicStroke( 4.0f ) );
plot.setRenderer( renderer );
setContentPane( chartPanel );
}
private XYDataset createDataset( ) {
final XYSeries temp = new XYSeries( "Temperature" );
//time = getTime(); //returns a float time in seconds.milliseconds
//temperature = getTemp(); //returns a number temperature
//I want to add data into temp every 5 seconds but i don't know how to do it
temp.add( 1.0 , 1.0 );
temp.add( 2.0 , 4.0 );
temp.add( 3.0 , 3.0 );
final XYSeriesCollection dataset = new XYSeriesCollection( );
dataset.addSeries( temp );
return dataset;
}
public static void main( String[ ] args ) {
XYLineChart_AWT chart = new XYLineChart_AWT("Temp",
"Temperature of some location");
chart.pack( );
RefineryUtilities.centerFrameOnScreen( chart );
chart.setVisible( true );
}
}
與其在您的createDataset()
方法中放置一個計時器,不如從您的main方法中生成一個新線程,該線程每5秒修改一次JFreeChart數據集。
例如,您可以執行以下操作:
public static void main( String[ ] args ) {
XYLineChart_AWT chart = new XYLineChart_AWT("Temp",
"Temperature of some location");
chart.pack( );
RefineryUtilities.centerFrameOnScreen( chart );
chart.setVisible( true );
//now make your timer
int delay = 5000; //milliseconds
ActionListener timerAction = new ActionListener() {
public void actionPerformed(ActionEvent evt) {
//some code here to get and modify your dataset so it can be updated
// ----
// ----
//now apply your new dataset to your JFreeChart
xylineChart.getXYPlot().setDataset(myNewDataset);
}
};
new Timer(delay, timerAction).start();
}
請記住添加一些代碼以刪除數據集中的舊條目,以使圖表保持可讀性,並且時間軸上的所有值在不同數據集之間保持相同的距離,例如,確保不超過24個項目(2分鍾數據)一次繪制。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.