springboot 复杂导入excel

可以使用 Apache POI 库来实现 Spring Boot 中的复杂导入 Excel。具体步骤如下：

1. 引入 Apache POI 依赖：

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.2</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.2</version>
</dependency>

2. 创建 Excel 文件读取器：

public class ExcelReader {
    public static List<Map<String, Object>> readExcel(InputStream inputStream, String fileName) throws IOException {
        Workbook workbook = null;
        if (fileName.endsWith(".xls")) {
            workbook = new HSSFWorkbook(inputStream);
        } else if (fileName.endsWith(".xlsx")) {
            workbook = new XSSFWorkbook(inputStream);        }
        Sheet sheet = workbook.getSheetAt(0);
        List<Map<String, Object>> list = new ArrayList<>();
        List<String> titles = new ArrayList<>();
        for (int i = 0; i <= sheet.getLastRowNum(); i++) {
            Row row = sheet.getRow(i);
            if (row == null) {
                continue;
            }
            Map<String, Object> map = new HashMap<>();
            for (int j = 0; j < row.getLastCellNum(); j++) {
                Cell cell = row.getCell(j);
                if (cell == null) {
                    continue;
                }
                if (i == 0) {
                    titles.add(cell.getStringCellValue());
                } else {
                    map.put(titles.get(j), getCellValue(cell));
                }
            }
            if (i != 0) {
                list.add(map);
            }
        }
        return list;
    }

    private static Object getCellValue(Cell cell) {
        Object value = null;
        switch (cell.getCellType()) {
            case STRING:
                value = cell.getStringCellValue();
                break;
            case NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    value = cell.getDateCellValue();
                } else {
                    value = cell.getNumericCellValue();
                }
                break;
            case BOOLEAN:
                value = cell.getBooleanCellValue();
                break;
            case FORMULA:
                value = cell.getCellFormula();
                break;
            default:
                break;
        }
        return value;
    }
}

3. 在 Controller 中使用 ExcelReader 读取 Excel 文件：

@PostMapping("/import")
public String importExcel(@RequestParam("file") MultipartFile file) throws IOException {
    List<Map<String, Object>> list = ExcelReader.readExcel(file.getInputStream(), file.getOriginalFilename());
    // 处理 Excel 数据
    return "success";
}