back/src/main/java/com/zh/lingnuo/utils/ExcelExport.java

package com.zh.lingnuo.utils;

import org.apache.poi.xssf.usermodel.*;

import java.util.*;

/**
 * 将List<Map<String,Object>> 类型数据导出到Excel文件
 */
public class ExcelExport {

    /**
     * src:定义下载的文件路径
     *
     * @param src
     * @return
     */
    public static XSSFWorkbook createExcel(LinkedHashMap<String, List<Map>> sheetList, String src) {
        // 定义一个新的工作簿
        XSSFWorkbook wb = new XSSFWorkbook();
        s
        for (Map.Entry<String, List<Map>> entry : sheetList.entrySet()) {
            String sheetName = entry.getKey();
            List<Map> list = entry.getValue();
            if( list.size() == 0){
                continue;
            }
            // 创建一个Sheet页
            XSSFSheet sheet = wb.createSheet(sheetName);
            //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);
            //根据需要给第一行每一列设置标题
            int rowCellIndex = 0;
            XSSFCell cell = row.createCell(rowCellIndex);
            if (null == list || list.size() == 0) {
                return wb;
            }
            Set<Object> keys = list.get(0).keySet();
            Object[] keysArray = keys.toArray();
            for (Object key : keys) {
                cell = row.createCell(rowCellIndex);

                cell.setCellValue(key.toString());

                rowCellIndex++;
            }
            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 < list.size(); i++) {

                // 在这个sheet页里创建一行
                rows = sheet.createRow(i + 1);
                // 该行创建一个单元格,在该单元格里设置值
                rowCellIndex = 0;
                for (Object s : keysArray) {
                    cells = rows.createCell(rowCellIndex);
                    cells.setCellValue(null == list.get(i).get(s) ? "" : list.get(i).get(s).toString());
                    rowCellIndex++;
                }
            }
        }
//        try {
//            File file = new File(src);
//            FileOutputStream fileOutputStream = new FileOutputStream(file);
//            wb.write(fileOutputStream);
//            wb.close();
//            fileOutputStream.close();
//        } catch (IOException e) {
//            e.printStackTrace();
//        }
        return wb;

    }
}