poi导出柱状图的代码

下面是使用Apache POI库导出柱状图的示例代码：

import java.io.FileOutputStream;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.*;

public class BarChartExample {

   public static void main(String[] args) throws Exception {

      //创建工作簿
      Workbook workbook = new XSSFWorkbook();

      //创建工作表
      Sheet sheet = workbook.createSheet("Bar Chart Example");

      //定义数据
      Object[][] data = {
         {"Month", "Sales"},
         {"January", 100},
         {"February", 120},
         {"March", 80},
         {"April", 90},
         {"May", 110},
         {"June", 130},
         {"July", 70},
         {"August", 90},
         {"September", 100},
         {"October", 120},
         {"November", 80},
         {"December", 90}
      };

      //创建行和单元格，并填充数据
      int rowNum = 0;
      for (Object[] rowData : data) {
         Row row = sheet.createRow(rowNum++);
         int colNum = 0;
         for (Object field : rowData) {
            Cell cell = row.createCell(colNum++);
            if (field instanceof String) {
               cell.setCellValue((String) field);
            } else if (field instanceof Integer) {
               cell.setCellValue((Integer) field);
            }
         }
      }

      //创建柱状图
      Drawing drawing = sheet.createDrawingPatriarch();
      ClientAnchor anchor = drawing.createAnchor(0, 0, 0, 0, 5, 1, 15, 20);
      Chart chart = drawing.createChart(anchor);

      //设置图表类型和标题
      ChartLegend legend = chart.getOrCreateLegend();
      legend.setPosition(LegendPosition.TOP_RIGHT);
      BarChartData dataChart = chart.getChartDataFactory().createBarChartData();
      ChartAxis bottomAxis = chart.getChartAxisFactory().createCategoryAxis(AxisPosition.BOTTOM);
      ValueAxis leftAxis = chart.getChartAxisFactory().createValueAxis(AxisPosition.LEFT);
      leftAxis.setCrosses(AxisCrosses.AUTO_ZERO);
      ChartDataSource<Number> xs = DataSources.fromNumericCellRange(sheet, new CellRangeAddress(1, 12, 1, 1));
      ChartDataSource<Number> ys1 = DataSources.fromNumericCellRange(sheet, new CellRangeAddress(1, 12, 2, 2));
      dataChart.addSeries(xs, ys1);
      chart.plot(dataChart, bottomAxis, leftAxis);

      //保存工作簿到文件
      FileOutputStream fileOut = new FileOutputStream("bar-chart-example.xlsx");
      workbook.write(fileOut);
      fileOut.close();
      System.out.println("The bar chart has been exported to bar-chart-example.xlsx");
   }
}

这个示例代码会创建一个柱状图，并将其导出到名为“bar-chart-example.xlsx”的Excel文件中。可以根据需要修改数据、图表类型、图表位置等。