需求如标题，项目需要把单个查询到接口数据导出一个Excel文件，因为字段比较多，列出来的话比较工作量比较大，就写了一个导出功能，遍历属性值导出。

        示例如下：

        1、导入poi依赖

<!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
<!--poi start-->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.15</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml-schemas</artifactId>
            <version>3.15</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.15</version>
        </dependency>
<!--poi end-->

        2、代码如下：

package com.bypay.server.test;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.apache.poi.xssf.usermodel.*;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.*;

/**
 * 将List<Map<String,Object>> 类型数据导出到Excel文件
 */
public class DataToExcel {
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    public static class Student {
        String name;
        int age;
        String sex;
    }

    /**
     * src:定义下载的文件路径
     *
     * @param mapArrayList
     * @param src
     */
    public static void createExcel(List<Map<String, Object>> mapArrayList, String src) {

        System.out.println("数据转成Excel...");

        //获取数据源的 key, 用于获取列数及设置标题
        Map<String, Object> map = mapArrayList.get(0);
        Set<String> stringSet = map.keySet();
        ArrayList<String> headList = new ArrayList<>(stringSet);

        // 定义一个新的工作簿
        XSSFWorkbook wb = new XSSFWorkbook();
        // 创建一个Sheet页
        XSSFSheet sheet = wb.createSheet("First sheet");
        //设置行高
        sheet.setDefaultRowHeight((short) (2 * 256));
        //设置列宽
        sheet.setColumnWidth(0, 4000);
        sheet.setColumnWidth(1, 4000);
        sheet.setColumnWidth(2, 4000);
        XSSFFont font = wb.createFont();
        font.setFontName("宋体");
        font.setFontHeightInPoints((short) 16);
        //获得表格第一行
        XSSFRow row = sheet.createRow(0);

        //chen 优化标题获取 根据数据源信息给第一行每一列设置标题
        for (int i = 0; i < headList.size(); i++) {
            XSSFCell cell = row.createCell(i);
            cell.setCellValue(headList.get(i));
        }

        XSSFRow rows;
        XSSFCell cells;
        //循环拿到的数据给所有行每一列设置对应的值
        for (int i = 0; i < mapArrayList.size(); i++) {

            // 在这个sheet页里创建一行
            rows = sheet.createRow(i + 1);
            //chen 优化值获取 给该行数据赋值
            for (int j = 0; j < headList.size(); j++) {
                String value;
                if (mapArrayList.get(i).get(headList.get(j)) != null) {
                    value = mapArrayList.get(i).get(headList.get(j)).toString();
                } else {
                    value = "";
                }
                cells = rows.createCell(j);
                cells.setCellValue(value);
            }
        }
        try {
            File file = new File(src);
            FileOutputStream fileOutputStream = new FileOutputStream(file);
            wb.write(fileOutputStream);
            wb.close();
            fileOutputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

    public static void main(String[] args) {

        System.out.println("数据加载...");
        List<Map<String,Object>> list = new ArrayList<>();
        Map<String,Object> map = new HashMap<>();
        map.put("名称","iphone13");
        map.put("属性1",1);
        map.put("属性2",2);
        map.put("属性3",3);

        Map<String,Object> map1 = new HashMap<>();
        map1.put("名称","iphone12");
        map1.put("属性1",1);
        map1.put("属性2",2);
        map1.put("属性3",3);

        Map<String,Object> map2 = new HashMap<>();
        map2.put("名称","iphone11");
        map2.put("属性1",1);
        map2.put("属性3",3);

        list.add(map);
        list.add(map1);
        list.add(map2);

        createExcel(list,"d:/dddd.xls");
    }

}