springboot + poi導出(excel)表格,支持中文自適應列寬

前言

優化springboot+poi導出excel表格,支持中文自適應的工具類.

工具類

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFCell;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLEncoder;

public class ExportEncodeUtil {
    public static void HeaderCode(HttpServletRequest request, HttpServletResponse response, String sheetName, HSSFWorkbook wb) throws IOException {
        // 針對IE或者以IE爲內核的瀏覽器：
        String userAgent = request.getHeader("User-Agent").toLowerCase();
        String fileName = sheetName + ".xlsx";
        if (userAgent.contains("msie") || userAgent.contains("trident")) {
            fileName = URLEncoder.encode(fileName, "UTF-8");
        } else {
            // 非IE瀏覽器的處理：
            fileName = new String(fileName.getBytes("UTF-8"), "ISO-8859-1");
        }
        response.setCharacterEncoding("UTF-8");
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        response.setHeader("success", "true");
        OutputStream os = response.getOutputStream();
        response.setHeader("Content-disposition", "attachment;filename=" + fileName);//默認Excel名稱

        wb.write(os);
        os.flush();
        os.close();
    }

    /**
     * 自適應寬度(中文支持)
     *  @param sheet
     * @param size
     */
    public static void setSizeColumn(HSSFSheet sheet, int size) {
        for (int columnNum = 0; columnNum < size; columnNum++) {
            int columnWidth = sheet.getColumnWidth(columnNum) / 256;
            for (int rowNum = 0; rowNum < sheet.getLastRowNum(); rowNum++) {
                HSSFRow currentRow;
                //當前行未被使用過
                if (sheet.getRow(rowNum) == null) {
                    currentRow = sheet.createRow(rowNum);
                } else {
                    currentRow = sheet.getRow(rowNum);
                }

                if (currentRow.getCell(columnNum) != null) {
                    HSSFCell currentCell = currentRow.getCell(columnNum);
                    if (currentCell.getCellType() == XSSFCell.CELL_TYPE_STRING) {
                        int length = currentCell.getStringCellValue().getBytes().length;
                        if (columnWidth < length) {
                            columnWidth = length;
                        }
                    }
                }
            }
            sheet.setColumnWidth(columnNum, columnWidth * 256);
        }
    }
}

service層關鍵代碼

/**
     * 導出excel表格
     *  get方法
     * @param request
     * @param response
     * @return
     * @throws Exception
     */
    public String export(HttpServletRequest request, HttpServletResponse response) throws Exception {
        List<Company> companies = companyRepository.findAll();
        HSSFWorkbook wb = new HSSFWorkbook();//創建Excel文件
        HSSFSheet sheet = wb.createSheet("企業信息表");
        String sheetName = sheet.getSheetName();
        wb.setSheetName(0, sheetName);
        sheet.setDefaultRowHeight((short) (20 * 20));
        CellStyle style = wb.createCellStyle();
        HSSFFont font = wb.createFont();
        font.setFontHeightInPoints((short) 12);
        style.setFont(font);
        HSSFRow row = sheet.createRow(0);
        row.createCell(0).setCellValue("企業名稱");//爲第一個單元格設值
        row.createCell(1).setCellValue("社會信用代碼");//爲第二個單元格設值
        row.createCell(2).setCellValue("聯繫人");//爲第三個單元格設值
        row.createCell(3).setCellValue("聯繫電話");//爲第三個單元格設值
        row.createCell(4).setCellValue("法人");//爲第三個單元格設值
        row.createCell(5).setCellValue("地址");
        row.createCell(6).setCellValue("行業");
        row.createCell(7).setCellValue("創建日期");
        row.createCell(8).setCellValue("開業日期");
        row.createCell(9).setCellValue("員工數");

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        if (companies != null && companies.size() > 0) {
            int i = 0;
            for (Company company : companies) {
                i++;
                row = sheet.createRow(i);
                row.createCell(0).setCellValue(company.getName());
                row.createCell(1).setCellValue(company.getCreditCode());
                row.createCell(2).setCellValue(company.getContactName());
                row.createCell(3).setCellValue(company.getContactPhone());
                row.createCell(4).setCellValue(company.getCorporation());
                row.createCell(5).setCellValue(company.getAddress());
                row.createCell(6).setCellValue(company.getIndustryName());

                String establishedDate = company.getEstablishedDate() != null ? sdf.format(company.getEstablishedDate()) : "";
                row.createCell(7).setCellValue(establishedDate);
                String openedDate = company.getOpenedDate() != null ? sdf.format(company.getOpenedDate()) : "";
                row.createCell(8).setCellValue(openedDate);
                Integer staffNum = company.getStaffNum() == null ? 0 : company.getStaffNum();
                row.createCell(9).setCellValue(staffNum);
            }
        }

         ExportEncodeUtil.setSizeColumn(sheet, companies .size());
        ExportEncodeUtil.HeaderCode(request, response, sheetName, wb);
        return "導出企業信息成功";
    }