使用Apache POI创建Excel折线图并保存为图片

本教程将指导您使用Apache POI库在Java中创建Excel折线图。我们将涵盖以下步骤：

读取Excel文件数据2. 创建折线图3. 设置图例和轴4. 添加数据系列5. 将图表保存到Excel文件6. 将图表保存为图片文件

代码示例

以下是一个完整的Java代码示例，演示如何创建Excel折线图并将其保存为图片：javaimport org.apache.poi.ss.util.CellRangeAddress;import org.apache.poi.xddf.usermodel.chart.;import org.apache.poi.xssf.usermodel.;

import javax.imageio.ImageIO;import java.awt.image.BufferedImage;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;

public class ExcelChartExample03 {

public static void main(String[] args) {        try {            // 读取Excel文件            FileInputStream fileIn = new FileInputStream('巴新EDEVU水库数据处理表.xlsx');            XSSFWorkbook workbook = new XSSFWorkbook(fileIn);            XSSFSheet sheet1 = workbook.getSheet('P9');            XSSFSheet sheet2 = workbook.getSheet('P10');

        // 创建折线图 (在'P10'工作表)            XSSFDrawing drawing = sheet2.createDrawingPatriarch();            XSSFClientAnchor anchor = drawing.createAnchor(0, 0, 0, 0, 3, 9, 9, 19);            XSSFChart chart = drawing.createChart(anchor);            chart.setTitleText('数据折线图');            chart.setTitleOverlay(false);

        // 设置图例位置            XDDFChartLegend legend = chart.getOrAddLegend();            legend.setPosition(LegendPosition.BOTTOM);

        // 创建数据系列            XDDFCategoryAxis bottomAxis = chart.createCategoryAxis(AxisPosition.BOTTOM);            XDDFValueAxis leftAxis = chart.createValueAxis(AxisPosition.LEFT);            leftAxis.setCrosses(AxisCrosses.AUTO_ZERO);

        // 创建数据源            XDDFNumericalDataSource<Double> xs1 = XDDFDataSourcesFactory.fromNumericCellRange(sheet1, new CellRangeAddress(11, 85, 0, 0));            XDDFNumericalDataSource<Double> ys1 = XDDFDataSourcesFactory.fromNumericCellRange(sheet1, new CellRangeAddress(11, 85, 2, 2));            XDDFNumericalDataSource<Double> xs2 = XDDFDataSourcesFactory.fromNumericCellRange(sheet2, new CellRangeAddress(11, 139, 0, 0));            XDDFNumericalDataSource<Double> ys2 = XDDFDataSourcesFactory.fromNumericCellRange(sheet2, new CellRangeAddress(11, 139, 2, 2));

        // 添加数据系列            XDDFLineChartData data = (XDDFLineChartData) chart.createData(ChartTypes.LINE, bottomAxis, leftAxis);            XDDFLineChartData.Series series1 = (XDDFLineChartData.Series) data.addSeries(xs1, ys1);            series1.setTitle('P9数据折线图', null);            XDDFLineChartData.Series series2 = (XDDFLineChartData.Series) data.addSeries(xs2, ys2);            series2.setTitle('P10数据折线图', null);

        // 绘制图表            chart.plot(data);

        // 创建'温度'工作表 (如果不存在)            XSSFSheet sheet3 = workbook.getSheet('温度');            if (sheet3 == null) {                sheet3 = workbook.createSheet('温度');            }

        // 将图表复制到'温度'工作表            XSSFDrawing drawing2 = sheet3.createDrawingPatriarch();            XSSFClientAnchor anchor2 = drawing2.createAnchor(0, 0, 0, 0, 0, 0, 10, 20);            XSSFChart chart2 = drawing2.createChart(anchor2);            chart2.setTitleText('数据折线图');            chart2.setTitleOverlay(false);            XDDFCategoryAxis bottomAxis2 = chart2.createCategoryAxis(AxisPosition.BOTTOM);            XDDFValueAxis leftAxis2 = chart2.createValueAxis(AxisPosition.LEFT);            leftAxis2.setCrosses(AxisCrosses.AUTO_ZERO);            XDDFLineChartData data2 = (XDDFLineChartData) chart2.createData(ChartTypes.LINE, bottomAxis2, leftAxis2);            data2.addSeries(xs1, ys1);            data2.addSeries(xs2, ys2);            chart2.plot(data2);

        // 将'温度'工作表中的图表保存为图片            BufferedImage image = new BufferedImage(800, 600, BufferedImage.TYPE_INT_RGB);            image.createGraphics();            chart2.plot(data2);            ImageIO.write(image, 'png', new File('温度折线图.png'));

        // 保存Excel文件            FileOutputStream fileOut = new FileOutputStream('巴新EDEVU水库数据处理表.xlsx');            workbook.write(fileOut);            fileOut.close();

        System.out.println('折线图已创建并保存到Excel文件和图片中。');

    } catch (IOException e) {            e.printStackTrace();        }