Java使用JFreeChart创建动态图表的代码示例

<dependency>
    <groupId>org.jfree</groupId>
    <artifactId>jfreechart</artifactId>
    <version>1.5.3</version>
</dependency>

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtils;
import org.jfree.chart.JFreeChart;
import org.jfree.data.category.DefaultCategoryDataset;

import java.io.File;
import java.io.IOException;

public class LineChartExample {
    public static void main(String[] args) {
        // 创建数据集
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();
        dataset.addValue(1, "Series1", "Category1");
        dataset.addValue(4, "Series1", "Category2");
        dataset.addValue(3, "Series1", "Category3");
        dataset.addValue(5, "Series1", "Category4");

        // 创建折线图
        JFreeChart chart = ChartFactory.createLineChart(
                "Sample Line Chart", // 图表标题
                "Category",         // X轴标签
                "Value",            // Y轴标签
                dataset             // 数据集
        );

        // 保存图表为图片
        try {
            ChartUtils.saveChartAsPNG(new File("line_chart.png"), chart, 600, 400);
            System.out.println("Chart saved as line_chart.png");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import java.awt.Color;

// 设置图表背景色
chart.setBackgroundPaint(Color.WHITE);

// 设置绘图区域背景色
CategoryPlot plot = chart.getCategoryPlot();
plot.setBackgroundPaint(Color.LIGHT_GRAY);

import org.jfree.chart.renderer.category.LineAndShapeRenderer;

// 获取渲染器
LineAndShapeRenderer renderer = (LineAndShapeRenderer) plot.getRenderer();

// 设置折线颜色
renderer.setSeriesPaint(0, Color.RED); // 第一条折线为红色
renderer.setSeriesStroke(0, new BasicStroke(2.0f)); // 设置线条粗细

import org.jfree.chart.StandardChartTheme;

// 设置全局字体
StandardChartTheme chartTheme = new StandardChartTheme("CN");
chartTheme.setExtraLargeFont(new Font("宋体", Font.PLAIN, 20)); // 标题字体
chartTheme.setLargeFont(new Font("宋体", Font.PLAIN, 16));     // 图例字体
chartTheme.setRegularFont(new Font("宋体", Font.PLAIN, 14));   // 轴标签字体
ChartFactory.setChartTheme(chartTheme);

CategoryAxis categoryAxis = chart.getCategoryPlot().getDomainAxis();
categoryAxis.setMaximumCategoryLabelLines(2); // 允许每个标签最多两行
categoryAxis.setCategoryLabelPositions(CategoryLabelPositions.UP_45);  // 旋转标签
categoryAxis.setLowerMargin(0.0); // 去掉边缘空白
categoryAxis.setUpperMargin(0.0); // 去掉边缘空白

import org.jfree.chart.ChartUtils;

// 保存图表为 PNG 文件
ChartUtils.saveChartAsPNG(new File("chart.png"), chart, 800, 600);

import com.deepoove.poi.XWPFTemplate;
import com.deepoove.poi.data.PictureType;
import com.deepoove.poi.data.Pictures;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartUtils;
import org.jfree.chart.JFreeChart;
import org.jfree.data.category.DefaultCategoryDataset;

import java.io.File;
import java.io.FileInputStream;
import java.util.HashMap;
import java.util.Map;

public class DailyReportExample {
    public static void main(String[] args) throws Exception {
        // 创建数据集
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();
        dataset.addValue(10, "监测站", "00:00");
        dataset.addValue(20, "监测站", "06:00");
        dataset.addValue(30, "监测站", "12:00");
        dataset.addValue(40, "监测站", "18:00");

        // 创建折线图
        JFreeChart chart = ChartFactory.createLineChart(
                "监测站总在线数", // 图表标题
                "小时",         // X轴标签
                "数量",         // Y轴标签
                dataset         // 数据集
        );

        // 保存图表为图片
        String chartPath = "daily_chart.png";
        ChartUtils.saveChartAsPNG(new File(chartPath), chart, 800, 600);

        // 将图片插入到 Word 文档
        Map<String, Object> dataMap = new HashMap<>();
        dataMap.put("chart", Pictures.ofStream(new FileInputStream(chartPath), PictureType.PNG).create());

        XWPFTemplate template = XWPFTemplate.compile("template.docx").render(dataMap);
        template.writeToFile("output.docx");
    }
}