Java Excel 数据处理：计算缺失日期的平均值

import org.apache.poi.ss.usermodel.*;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.*;

public class test04 {

    public static void main(String[] args) {
        try {
            // 从输入Excel文件中读取数据
            FileInputStream inputWorkbook = new FileInputStream('C:\Users\Administrator\Desktop\input.xlsx');
            Workbook workbook = WorkbookFactory.create(inputWorkbook);
            Sheet sheet = workbook.getSheetAt(0);
            int totalRows = sheet.getLastRowNum() + 1;
            ArrayList<Data> dataList = new ArrayList<>();
            for (int i = 1; i < totalRows; i++) {
                Row row = sheet.getRow(i);
                Data data = new Data();
                data.date = getDateFromCell(row.getCell(0));
                data.value = getValueFromCell(row.getCell(1));
                dataList.add(data);
            }
            inputWorkbook.close();

            // 按日期对数据排序
            Collections.sort(dataList);

            // 计算缺失日期的平均值
            Map<Date, Double> missingDataMap = new HashMap<>();
            for (int i = 0; i < dataList.size() - 1; i++) {
                Data currentData = dataList.get(i);
                Data nextData = dataList.get(i + 1);
                long diffInMillis = nextData.date.getTime() - currentData.date.getTime();
                long diffInDays = diffInMillis / (24 * 60 * 60 * 1000);
                if (diffInDays > 1) {
                    double diffInValue = nextData.value - currentData.value;
                    double dailyValue = diffInValue / diffInDays;
                    for (int j = 1; j < diffInDays; j++) {
                        Date missingDate = new Date(currentData.date.getTime() + j * (24 * 60 * 60 * 1000));
                        missingDataMap.put(missingDate, currentData.value + j * dailyValue);
                    }
                }
            }
            double totalMissingValue = 0.0;
            int totalMissingCount = missingDataMap.size();
            for (Double value : missingDataMap.values()) {
                totalMissingValue += value;
            }
            double averageMissingValue = totalMissingValue / totalMissingCount;

            // 将数据写入输出Excel文件
            Workbook outputWorkbook = WorkbookFactory.create(true);
            Sheet outputSheet = outputWorkbook.createSheet();
            CellStyle dateStyle = outputWorkbook.createCellStyle();
            dateStyle.setDataFormat(outputWorkbook.getCreationHelper().createDataFormat().getFormat('yyyy-mm-dd'));
            int rowIndex = 0;
            Row headerRow = outputSheet.createRow(rowIndex++);
            headerRow.createCell(0).setCellValue('Date');
            headerRow.createCell(1).setCellValue('Value');
            for (Data data : dataList) {
                Row row = outputSheet.createRow(rowIndex++);
                Cell dateCell = row.createCell(0);
                dateCell.setCellValue(data.date);
                dateCell.setCellStyle(dateStyle);
                row.createCell(1).setCellValue(data.value);
            }
            for (Map.Entry<Date, Double> entry : missingDataMap.entrySet()) {
                Row row = outputSheet.createRow(rowIndex++);
                Cell dateCell = row.createCell(0);
                dateCell.setCellValue(entry.getKey());
                dateCell.setCellStyle(dateStyle);
                row.createCell(1).setCellValue(entry.getValue());
            }
            Row averageRow = outputSheet.createRow(rowIndex);
            averageRow.createCell(0).setCellValue('Average missing value:');
            averageRow.createCell(1).setCellValue(averageMissingValue);
            FileOutputStream outputWorkbookFile = new FileOutputStream('output.xlsx');
            outputWorkbook.write(outputWorkbookFile);
            outputWorkbookFile.close();
            outputWorkbook.close();
            System.out.println('Data processing completed successfully.');
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static Date getDateFromCell(Cell cell) {
        if (cell.getCellType() == CellType.NUMERIC && DateUtil.isCellDateFormatted(cell)) {
            return cell.getDateCellValue();
        } else {
            DataFormatter formatter = new DataFormatter();
            try {
                return new SimpleDateFormat('yyyy-MM-dd').parse(formatter.formatCellValue(cell));
            } catch (Exception e) {
                e.printStackTrace();
                return null;
            }
        }
    }

    public static double getValueFromCell(Cell cell) {
        if (cell.getCellType() == CellType.NUMERIC ) {
            return cell.getNumericCellValue();
        } else {
            DataFormatter formatter = new DataFormatter();
            try {
                return Double.parseDouble(formatter.formatCellValue(cell));
            } catch (Exception e) {
                e.printStackTrace();
                return 0.0;
            }
        }
    }

    static class Data implements Comparable<Data> {
        Date date;
        double value;

        @Override
        public int compareTo(Data o) {
            return this.date.compareTo(o.date);
        }
    }
}

在IDEA中不能运行 解决办法内容： 该代码是一个完整的Java程序，需要在Java开发环境中运行，如Eclipse或IntelliJ IDEA等。如果在IDEA中无法运行，可能是因为没有正确配置Java开发环境或项目设置不正确。可以尝试将代码复制到一个新的Java项目中，并确保已正确配置Java环境和项目设置。