SpringBoot导出Excel

刚好有需求，封装了下较为通用的导出工具类

代码实现

maven依赖

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.17</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.17</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml-schemas</artifactId>
    <version>3.17</version>
</dependency>

工具类实现：

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.*;


/**
 * @Author：Ding Wenhao
 * @Date：2020-07-31 16:39
 * @Description：Excel导出工具类
 */
public class ExcelExportUtil {

    /**
     * 将传入的数据导出excel表并下载
     * @param response 返回的HttpServletResponse
     * @param importList 导出的数据Map
     * @param titleMap  标题Map, key ：importList 中 Map 的key ,即列对应的key  value : 标题文字
     * @param fileName 文件名
     */
    public static void export(HttpServletResponse response, List<Map> importList,Map<String,String> titleMap,String fileName) {
        // 声明工作薄
        HSSFWorkbook workbook = new HSSFWorkbook();
        // 生成表格
        HSSFSheet sheet = workbook.createSheet();
        // 设置表格默认列宽度为15个字节
        sheet.setDefaultColumnWidth((short) 18);
        // 循环字段名数组，创建标题行
        Row row = sheet.createRow(0);
        // 列key数组
        String[] columnKeys  = new String[titleMap.size()];
        // 处理Map key 并 创建标题行
        int position = 0;
        for(Map.Entry<String, String> vo : titleMap.entrySet()){
            String key = vo.getKey();
            String value = vo.getValue();
            // 创建列
            Cell cell = row.createCell(position);
            // 设置单元类型为String
            cell.setCellType(CellType.STRING);
            cell.setCellValue(value);
            columnKeys[position] = key;
            position++;
        }
        // 创建普通行
        for (int i = 0;i < importList.size();i++){
            // 从第二行开始
            row = sheet.createRow(i+1);
            for (int j = 0;j < columnKeys.length;j++){
                //创建列
                Cell cell = row.createCell(j);
                Map lineMap = importList.get(i);
                Object columnValue = lineMap.get(columnKeys[j]);
                if(CommonUtil.isEmpty(columnValue)){
                    // 数据为空 默认空字符
                    cell.setCellValue("");
                    cell.setCellType(CellType.STRING);
                }else if(columnValue instanceof Integer){
                    // 数字
                    cell.setCellValue((Integer)columnValue);
                    cell.setCellType(CellType.NUMERIC);
                }else if(columnValue instanceof Date){
                    // 日期
                    SimpleDateFormat sdfDay = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    cell.setCellValue(sdfDay.format(columnValue));
                    cell.setCellType(CellType.STRING);
                }else{
                    // 默认字符串
                    cell.setCellValue(columnValue.toString());
                    cell.setCellType(CellType.STRING);
                }
            }
        }
        response.setContentType("application/octet-stream;charset=utf-8");
        //默认Excel名称
        response.setHeader("Content-Disposition", "attachment;fileName="+fileName+".xls");
        try {
            response.flushBuffer();
            workbook.write(response.getOutputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

测试代码：

    @GetMapping("/import")
    public void importExcel(HttpServletResponse response){
        // 模拟查询数据
        List<Map> importList = new ArrayList<>();
        for(int i = 1; i <= 5; i++){
            Map map = new HashMap();
            map.put("fromUser","关注人"+i);
            map.put("createTime","关注时间"+i);
            map.put("eventKey","二维码来源"+i);
            importList.add(map);
        }
        // 处理标题
        Map<String,String> titleMap = new HashMap<>(3);
        titleMap.put("fromUser","关注人");
        titleMap.put("createTime","关注时间");
        titleMap.put("eventKey","二维码来源");
        ExcelExportUtil.export(response,importList,titleMap,"testData");
    }

导出结果：