在java中使用jfree图表制作动态折线图 [英] Making dynamic line chart using jfree chart in java

问题描述

如何使用java中的jFree图表创建动态折线图，该图表显示2小时之前的数据，并且还提供一个空白区域，数据显示从当前时间开始2小时。例如假设当前时间是下午4点，所以图表显示数据从下午2点到下午6点。下午2点到下午4点图表显示一条线，下午4点到下午6点提供一个空白区域，这是图表移动时填充的时间，这意味着该图形的尾部从中间开始向右移动。类似于股市图表。

how can i create dynamic line chart using jFree chart in java which is show data of 2 hours before and also provide a blank space where data show for 2 hours later from current time.For example suppose current time is 4pm ,so the chart display data from 2pm to 6pm.Here 2pm to 4pm the chart show a line and 4pm to 6pm provide a blank space which is fill time to time when the graph is moving that mean the tail of this graph is starting from middle and move right. similar like stock market chart.

推荐答案

是的，你可以做到。几天前我遇到了类似的问题。

Yes, you can do it. I was facing a similar problem a few days ago.

DynamicLineAndTimeSeriesChart.java

DynamicLineAndTimeSeriesChart.java

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.Timer;
import javax.swing.JPanel;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.ValueAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.data.time.Millisecond;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;

/**
 * An example to show how we can create a dynamic chart.
*/
public class DynamicLineAndTimeSeriesChart extends ApplicationFrame implements ActionListener {

    /** The time series data. */
    private TimeSeries series;

    /** The most recent value added. */
    private double lastValue = 100.0;

    /** Timer to refresh graph after every 1/4th of a second */
    private Timer timer = new Timer(250, this);

    /**
     * Constructs a new dynamic chart application.
     *
     * @param title  the frame title.
     */
    public DynamicLineAndTimeSeriesChart(final String title) {

        super(title);
        this.series = new TimeSeries("Random Data", Millisecond.class);

        final TimeSeriesCollection dataset = new TimeSeriesCollection(this.series);
        final JFreeChart chart = createChart(dataset);

        timer.setInitialDelay(1000);

        //Sets background color of chart
        chart.setBackgroundPaint(Color.LIGHT_GRAY);

        //Created JPanel to show graph on screen
        final JPanel content = new JPanel(new BorderLayout());

        //Created Chartpanel for chart area
        final ChartPanel chartPanel = new ChartPanel(chart);

        //Added chartpanel to main panel
        content.add(chartPanel);

        //Sets the size of whole window (JPanel)
        chartPanel.setPreferredSize(new java.awt.Dimension(800, 500));

        //Puts the whole content on a Frame
        setContentPane(content);

        timer.start();

    }

    /**
     * Creates a sample chart.
     *
     * @param dataset  the dataset.
     *
     * @return A sample chart.
     */
    private JFreeChart createChart(final XYDataset dataset) {
        final JFreeChart result = ChartFactory.createTimeSeriesChart(
            "Dynamic Line And TimeSeries Chart",
            "Time",
            "Value",
            dataset,
            true,
            true,
            false
        );

        final XYPlot plot = result.getXYPlot();

        plot.setBackgroundPaint(new Color(0xffffe0));
        plot.setDomainGridlinesVisible(true);
        plot.setDomainGridlinePaint(Color.lightGray);
        plot.setRangeGridlinesVisible(true);
        plot.setRangeGridlinePaint(Color.lightGray);

        ValueAxis xaxis = plot.getDomainAxis();
        xaxis.setAutoRange(true);

        //Domain axis would show data of 60 seconds for a time
        xaxis.setFixedAutoRange(60000.0);  // 60 seconds
        xaxis.setVerticalTickLabels(true);

        ValueAxis yaxis = plot.getRangeAxis();
        yaxis.setRange(0.0, 300.0);

        return result;
    }
    /**
     * Generates an random entry for a particular call made by time for every 1/4th of a second.
     *
     * @param e  the action event.
     */
    public void actionPerformed(final ActionEvent e) {

        final double factor = 0.9 + 0.2*Math.random();
        this.lastValue = this.lastValue * factor;

        final Millisecond now = new Millisecond();
        this.series.add(new Millisecond(), this.lastValue);

        System.out.println("Current Time in Milliseconds = " + now.toString()+", Current Value : "+this.lastValue);
    }

    /**
     * Starting point for the dynamic graph application.
     *
     * @param args  ignored.
     */
    public static void main(final String[] args) {

        final DynamicLineAndTimeSeriesChart demo = new DynamicLineAndTimeSeriesChart("Dynamic Line And TimeSeries Chart");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);

    }

}  

还请检查这里：

http://blog.odoobiz.com/2012/07/how-to-draw-dynamic-line-or-timeseries.html

这篇关于在java中使用jfree图表制作动态折线图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！