步骤：
1.查找官方API文档理解实现
2.实现融入到代码里面
一：Easy Excel动态头实时生成头写入
动态头实时生成头写入
二：实现
目的：实现表头为，第一列是固定列，第二列为动态生成的时间段的每一天的日期
步骤：
1.查询数据
2.创建表头
3.填充数据
例子：
package com.test.cn.sales.service.impl;import com.alibaba.excel.EasyExcel;import java.io.File;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;public class DynamicExcelExport {public static void main(String[] args) {//1.模拟从数据库中获取数据List<String> keywords = getKeywordsFromDatabase();List<SalesData> salesDataList = getSalesDataFromDatabase();//2.创建表头List<String> dates = generateDateRange("2023-12-30", "2024-02-02");// 根据开始和结束时间动态生成日期List<List<String>> head = new ArrayList<>();head.add(new ArrayList<>(Arrays.asList("关键字"))); // 第一列固定为关键字dates.forEach(o -> head.add(new ArrayList<>(Arrays.asList(o))));//3.填充数据List<List<Object>> data = fillData(keywords, salesDataList, dates);String outputPath = "E:\\output.xlsx"; // 输出路径修改为 E 盘EasyExcel.write(new File(outputPath)).head(head).sheet("Sheet1").doWrite(data);System.out.println("Excel 文件导出成功！输出路径：" + outputPath);}private static List<String> getKeywordsFromDatabase() {// 模拟从数据库中获取关键字return new ArrayList<>(Arrays.asList("关键字1", "关键字2", "关键字3"));}private static List<SalesData> getSalesDataFromDatabase() {// 模拟从数据库中获取销售数据List<SalesData> salesDataList = new ArrayList<>();salesDataList.add(new SalesData("关键字1", 100.00, "2023-12-30"));salesDataList.add(new SalesData("关键字2", 200.00, "2024-02-02"));salesDataList.add(new SalesData("关键字3", 300.00, "2024-02-01"));return salesDataList;}private static List<List<Object>> fillData(List<String> keywords, List<SalesData> salesDataList, List<String> dates) {// 填充数据List<List<Object>> data = new ArrayList<>();for (String keyword : keywords) {List<Object> rowData = new ArrayList<>();rowData.add(keyword); // 添加关键字for (String date : dates) {Double sales = getSalesForKeywordAndDate(keyword, date, salesDataList);rowData.add(sales != null ? sales : 0); // 添加销量数据}data.add(rowData);}return data;}private static Double getSalesForKeywordAndDate(String keyword, String date, List<SalesData> salesDataList) {// 根据关键字和日期从销售数据列表中获取销量数据for (SalesData salesData : salesDataList) {if (salesData.getKeyword().equals(keyword) && salesData.getDate().toString().equals(date)) {return salesData.getSales();}}return null;}/*** 时间段生成** @param startDateStr 开始时间* @param endDateStr 结束时间* @return list*/public static List<String> generateDateRange(String startDateStr, String endDateStr) {List<String> dateRange = new ArrayList<>();DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");LocalDate startDate = LocalDate.parse(startDateStr, formatter);LocalDate endDate = LocalDate.parse(endDateStr, formatter);while (!startDate.isAfter(endDate)) {dateRange.add(startDate.format(formatter));startDate = startDate.plusDays(1);}return dateRange;}
}class SalesData {private String keyword;private Double sales;private String date;public SalesData(String keyword, Double sales, String date) {this.keyword = keyword;this.sales = sales;this.date = date;}public String getKeyword() {return keyword;}public void setKeyword(String keyword) {this.keyword = keyword;}public Double getSales() {return sales;}public void setSales(Double sales) {this.sales = sales;}public String getDate() {return date;}public void setDate(String date) {this.date = date;}
}导出效果：
