Java如何利用Easyexcel动态导出表头列

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * @author: chenjiaxiang
 * @create: 2023/4/11 11:05
 **/
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class ExcelHeader {

    /**
     * 要导出的字段名称
     */
    private String fieldName;

    /**
     * 要导出的表头名称
     */
    private String headName;
}

import cn.hutool.core.util.ReflectUtil;
import com.alibaba.excel.EasyExcel;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

/**
 * 动态导出 exl
 * @author: chenjiaxiang
 * @create: 2023/4/11 16:20
 **/
@Slf4j
public class EasyExcelUtils {

    /**
     * 动态导出exl
     *
     * @param headers  要导出的头集合
     * @param dataList 数据集合
     */
    public static <T> void dynamicExportExcel(List<ExcelHeader> headers, List<T> dataList, HttpServletResponse response) {
        long startTime = System.currentTimeMillis();
        List<List<T>> allList = new ArrayList<>();
        for (T detail : dataList) {
            allList.addAll(EasyExcelUtils.dataList(headers, detail));
        }
        try (ServletOutputStream outputStream = response.getOutputStream()) {
            EasyExcel.write(outputStream).head(EasyExcelUtils.headers(headers))
                    //文件样式
                    .registerWriteHandler(new CellStyle())
                    .sheet("sheet").doWrite(allList);
        } catch (IOException e) {
            log.error("生成动态EXL失败，字段", e);
        }
        long endTime = System.currentTimeMillis();
        log.info("动态导出耗时:{}", endTime - startTime);
    }

    //excel表头
    public static List<List<String>> headers(List<ExcelHeader> excelHeaders) {
        List<List<String>> headers = new ArrayList<>();
        for (ExcelHeader header : excelHeaders) {
            List<String> head = new ArrayList<>();
            head.add(header.getHeadName());
            headers.add(head);
        }
        return headers;
    }

    /**
     * 要导出的字段
     *
     * @param exportFields 表头集合
     * @param obj          数据对象
     * @return 集合
     */
    @SneakyThrows
    public static <T> List<List<T>> dataList(List<ExcelHeader> exportFields, T obj) {
        List<List<T>> list = new ArrayList<>();
        List<T> data = new ArrayList<>();
        List<String> propList = exportFields.stream().map(ExcelHeader::getFieldName).collect(Collectors.toList());
        //先根据反射获取实体类的class对象
        Class<?> objClass = obj.getClass();
        //设置实体类属性的集合
        Field[] fields = ReflectUtil.getFields(objClass);
        for (String prop : propList) {
            //循环实体类对象集合
            for (Field field : fields) {
                field.setAccessible(true);
                //判断实体类属性跟特定字段集合名是否一样
                if (field.getName().equals(prop)) {
                    T object = (T) field.get(obj);
                    //获取属性对应的值
                    data.add(object);
                }
            }
        }
        list.add(data);
        return list;
    }

}

import com.alibaba.excel.metadata.CellData;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.style.column.AbstractColumnWidthStyleStrategy;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;

import java.util.List;

/**
 * @author: chenjiaxiang
 * @create: 2022-08-11 14:53
 **/
public class CellStyle extends AbstractColumnWidthStyleStrategy {

    @Override
    protected void setColumnWidth(WriteSheetHolder writeSheetHolder, List<CellData> cellDataList, Cell cell, Head head,
                                  Integer relativeRowIndex, Boolean isHead) {
        // 简单设置
        Sheet sheet = writeSheetHolder.getSheet();
        sheet.setColumnWidth(cell.getColumnIndex(), 5000);
    }

}

 @PostMapping("/exlOut")
    public void exlOut(HttpServletResponse response) {
        //导出字段集合
        List<ExcelHeader> excelHeaders = Arrays.asList(new ExcelHeader("phone", "手机号"), new ExcelHeader("sexStr", "性别"));
        //数据集合
        List<GetSchoolExpertsDeriveExlVo> getSchoolExpertsDeriveExlVos = Arrays.asList(new GetSchoolExpertsDeriveExlVo("男", "1231231"), new GetSchoolExpertsDeriveExlVo("nn", "adadad"));
        EasyExcelUtils.dynamicExportExcel(excelHeaders,getSchoolExpertsDeriveExlVos,response);
    }