SpringBoot整合EasyPoi实现复杂多级表头Excel导出的完整方案

graph LR
A[Spring Boot] --> B[Controller层]
B --> C[Service层]
C --> D[Entity实体类]
D --> E[EasyPoi导出引擎]
E --> F[Excel文件]

<dependency>
    <groupId>cn.afterturn</groupId>
    <artifactId>easypoi-base</artifactId>
    <version>4.4.0</version>
</dependency>
<dependency>
    <groupId>cn.afterturn</groupId>
    <artifactId>easypoi-web</artifactId>
    <version>4.4.0</version>
</dependency>

# Excel 导出配置
easypoi.export.head-rows=1
easypoi.export.sheet-name=Sheet1

@Data
public class FinancialReport {

    // 一级表头：财务概览
    @Excel(name = "财务概览/总收入", orderNum = "0", width = 20)
    private BigDecimal totalIncome;

    // 二级表头嵌套
    @Excel(name = "部门明细", orderNum = "1")
    private Department department;

    // 集合类型表头
    @ExcelCollection(name = "项目明细")
    private List<Project> projects;
}

@Data
public class Department {
    @Excel(name = "部门名称", orderNum = "0", width = 15)
    private String deptName;

    @Excel(name = "人员规模", orderNum = "1", width = 10)
    private Integer staffCount;
}

@Data
public class Project {
    @Excel(name = "项目名称", orderNum = "0", width = 25)
    private String projectName;

    // 三级表头
    @Excel(name = "成本明细/人力成本", orderNum = "1", width = 15)
    private BigDecimal laborCost;

    @Excel(name = "成本明细/设备成本", orderNum = "2", width = 15)
    private BigDecimal equipmentCost;
}

public class ExcelExportUtil {

    public static Workbook createWorkbook(List<FinancialReport> data) {
        Workbook workbook = new XSSFWorkbook();
        Sheet sheet = workbook.createSheet("财务报告");

        // 创建表头行
        Row headerRow = sheet.createRow(0);

        // 动态构建多级表头
        buildHeaderRow(headerRow, 0, data.getClass().getDeclaredFields());
        
        // 填充数据
        int rowNum = 1;
        for (FinancialReport report : data) {
            Row row = sheet.createRow(rowNum++);
            fillDataRow(row, report);
        }

        // 自动调整列宽
        for (int i = 0; i < headerRow.getLastCellNum(); i++) {
            sheet.autoSizeColumn(i);
        }

        return workbook;
    }

    private static void buildHeaderRow(Row row, int level, Field[] fields) {
        for (Field field : fields) {
            Excel excel = field.getAnnotation(Excel.class);
            if (excel != null) {
                Cell cell = row.createCell(excel.orderNum());
                cell.setCellValue(excel.name());
                
                // 处理合并单元格
                if (excel.mergeVertical() || excel.mergeHorizontal()) {
                    sheet.addMergedRegion(new CellRangeAddress(
                        0, 0, 
                        excel.orderNum(), 
                        excel.orderNum() + excel.name().split("/").length - 1
                    ));
                }
                
                // 递归处理嵌套表头
                if (!Collection.class.isAssignableFrom(field.getType())) {
                    buildHeaderRow(row, level + 1, field.getType().getDeclaredFields());
                }
            }
        }
    }

    private static void fillDataRow(Row row, Object obj) {
        Field[] fields = obj.getClass().getDeclaredFields();
        for (Field field : fields) {
            field.setAccessible(true);
            try {
                Cell cell = row.createCell(field.getAnnotation(Excel.class).orderNum());
                cell.setCellValue(field.get(obj).toString());
            } catch (IllegalAccessException e) {
                e.printStackTrace();
            }
        }
    }
}

@RestController
@RequestMapping("/export")
public class ExcelController {

    @Autowired
    private ReportService reportService;

    @GetMapping("/financial-report")
    public void exportFinancialReport(HttpServletResponse response) {
        try {
            // 生成数据
            List<FinancialReport> data = reportService.generateReportData();

            // 创建工作簿
            Workbook workbook = ExcelExportUtil.createWorkbook(data);

            // 设置响应头
            response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
            response.setHeader("Content-Disposition", 
                "attachment;filename=" + URLEncoder.encode("财务报告.xlsx", "UTF-8"));

            // 写入输出流
            workbook.write(response.getOutputStream());
            workbook.close();
        } catch (Exception e) {
            throw new RuntimeException("导出失败：" + e.getMessage());
        }
    }
}

# 大数据量导出配置
easypoi.export.big-data=true
easypoi.export.row-access-window-size=100

public class DynamicHeaderBuilder {
    
    public static List<ExcelExportEntity> buildDynamicHeader() {
        List<ExcelExportEntity> entities = new ArrayList<>();
        
        // 一级表头
        ExcelExportEntity parent = new ExcelExportEntity("财务分析", "finance");
        parent.setNeedMerge(true);
        
        // 二级表头
        ExcelExportEntity child1 = new ExcelExportEntity("收入分析", "income");
        ExcelExportEntity child2 = new ExcelExportEntity("支出分析", "expense");
        
        // 三级表头
        ExcelExportEntity grandChild1 = new ExcelExportEntity("销售收入", "sales");
        ExcelExportEntity grandChild2 = new ExcelExportEntity("运营成本", "operating");
        
        // 构建层级关系
        child1.setList(Arrays.asList(grandChild1));
        child2.setList(Arrays.asList(grandChild2));
        parent.setList(Arrays.asList(child1, child2));
        
        entities.add(parent);
        return entities;
    }
}

public class CustomStyleUtil {
    
    public static CellStyle createHeaderStyle(Workbook workbook) {
        CellStyle style = workbook.createCellStyle();
        Font font = workbook.createFont();
        font.setBold(true);
        font.setColor(IndexedColors.WHITE.getIndex());
        
        style.setFont(font);
        style.setFillForegroundColor(IndexedColors.DARK_BLUE.getIndex());
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        style.setAlignment(HorizontalAlignment.CENTER);
        
        return style;
    }
}

TemplateExportParams params = new TemplateExportParams("template.xlsx");
Map<String, Object> data = new HashMap<>();
data.put("title", "财务报告");
data.put("detail", reportData);
Workbook workbook = ExcelExportUtil.exportExcel(params, data);

List<ExcelExportEntity> dynamicColumns = new ArrayList<>();
dynamicColumns.add(new ExcelExportEntity("动态列1", "field1"));
dynamicColumns.add(new ExcelExportEntity("动态列2", "field2"));
ExcelExportUtil.exportBigExcel(params, dynamicColumns, data);