Follow Fang!: Java 長條圖(JfreeChart)

JfreeChart是一套Java還蠻知名的Chart套件。有提供長條圖、曲線圖、圓餅圖等等多種圖形，還有提供Chart範本，這次範例是jfreechart-1.0.14.zip實做範例

JfreeChart本身應該是繼承Swing和awt所沿生出來的套件，所以寫法對於會寫Swing以及awt的人應該是不陌生，不外乎就是設定Jframe、Panel等等

不熟悉的人可以看一下JfreeChart所提供的原始碼並搭配JfreeChart API來學習

以下的Code某些部份是沿用範本BarChartDemo1，我刪掉用不太到的Code，所以可能會略為精簡一些

import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.BarRenderer;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;

public class Chart extends ApplicationFrame {

    private static final long serialVersionUID = 1L;

    public Chart(String title) {
        super(title);
        CategoryDataset dataset = createDataset();
        JFreeChart chart = createChart(dataset);
        ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setFillZoomRectangle(true);
        chartPanel.setMouseWheelEnabled(true); // 讓滑鼠滾輪可以放大縮小
        chartPanel.setPreferredSize(new Dimension(600, 480));
        setContentPane(chartPanel);
    }

    private static CategoryDataset createDataset() {

        String series1 = "A";
        String series2 = "B";
        String series3 = "C";

        String category1 = "Category 1";

        DefaultCategoryDataset dataset = new DefaultCategoryDataset();

        dataset.addValue(1.0, series1, category1);
        dataset.addValue(7.0, series2, category1);
        dataset.addValue(100.0, series3, category1);

        return dataset;
    }

    private static JFreeChart createChart(CategoryDataset dataset) {

        // 建立長條圖
        JFreeChart chart = ChartFactory
                .createBarChart("Title", "Y label", "X label", dataset,
                        PlotOrientation.VERTICAL, true, true, false);

        // 設定背景顏色
        chart.setBackgroundPaint(Color.white);

        CategoryPlot plot = (CategoryPlot) chart.getPlot();

        // 設定Y軸數值
        NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
        rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());

        BarRenderer renderer = (BarRenderer) plot.getRenderer();
        renderer.setDrawBarOutline(false);

        // 畫出長條圖
        GradientPaint gp0 = new GradientPaint(0.0f, 0.0f, Color.blue, 0.0f,
                0.0f, new Color(0, 0, 64));
        GradientPaint gp1 = new GradientPaint(0.0f, 0.0f, Color.green, 0.0f,
                0.0f, new Color(0, 64, 0));
        GradientPaint gp2 = new GradientPaint(0.0f, 0.0f, Color.red, 0.0f,
                0.0f, new Color(64, 0, 0));
        renderer.setSeriesPaint(0, gp0);
        renderer.setSeriesPaint(1, gp1);
        renderer.setSeriesPaint(2, gp2);

        return chart;
    }

    public static void main(String[] args) {
        Chart chart = new Chart("Test");
        chart.pack(); // 動態設定元件大小
        RefineryUtilities.centerFrameOnScreen(chart);
        chart.setVisible(true);
    }

}

參考資料：
http://puremonkey2010.blogspot.tw/2011/06/java-jfreechart-part-1.html
http://hsingyu-jcworld.blogspot.tw/2012/01/javajfreechart.html
http://www.jfree.org/jfreechart/api/javadoc/index.html

2013/01/26

Java 長條圖(JfreeChart)