human-resources-server/src/main/java/com/jingcheng/cms/util/ExcelUtils.java

package com.jingcheng.cms.util;

import org.apache.poi.hssf.usermodel.DVConstraint;
import org.apache.poi.hssf.usermodel.HSSFDataValidation;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddressList;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;

/**
 * @author ybin
 * @version 1.0
 * @date 2021/1/22 14:51
 * @description:
 */

public class ExcelUtils {
    private static Logger logger = LoggerFactory.getLogger(ExcelUtils.class);

    /**
     *
     * @param in
     * @param fileName
     * @return
     * @throws Exception
     */
    public static List getCourseListByExcel(InputStream in, String fileName) throws Exception {
        List list = new ArrayList<>();
        // 创建excel工作簿
        Workbook work = getWorkbook(in, fileName);
        if (null == work) {
            throw new Exception("创建Excel工作薄为空！");
        }
        Sheet sheet = null;
        Row row = null;
        Cell cell = null;
        for (int i = 0; i < work.getNumberOfSheets(); i++) {
            sheet = work.getSheetAt(i);
            if(sheet == null) {
                continue;
            }
            // 滤过第一行标题
            for (int j = sheet.getFirstRowNum(); j <= sheet.getLastRowNum(); j++) {
                row = sheet.getRow(j);
                if (row == null || row.getFirstCellNum() == j) {
                    continue;
                }
                List<Object> li = new ArrayList<>();

                for (int y = row.getFirstCellNum(); y < row.getLastCellNum(); y++) {
                    cell = row.getCell(y);
                    // 日期类型转换
                    if(y == 3) {
                        //cell.setCellType(CellType.STRING);
                        double s1 = cell.getNumericCellValue();
                        Date date = HSSFDateUtil.getJavaDate(s1);
                        li.add(date);
                        continue;
                    }
                    li.add(cell);
                }
                list.add(li);
            }
        }
        work.close();
        return list;
    }

    /**
     * 判断文件格式
     * @param in
     * @param fileName
     * @return
     */
    private static Workbook getWorkbook(InputStream in, String fileName) throws Exception {
        Workbook book = null;
        String filetype = fileName.substring(fileName.lastIndexOf("."));
        if (".xls".equals(filetype)) {
            book = new HSSFWorkbook(in);
        } else if (".xlsx".equals(filetype)) {
            book = new XSSFWorkbook(in);
        } else {
            throw new Exception("请上传excel文件！");
        }
        return book;
    }

    public static void export(Workbook wb, HttpServletResponse response, String tableName) {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        BufferedInputStream bis = null;
        BufferedOutputStream bos = null;
        InputStream is = null;
        try {
            wb.write(os);
            byte[] content = os.toByteArray();
            is = new ByteArrayInputStream(content);
            tableName = URLEncoder.encode(tableName, "UTF-8");
            response.reset();
            response.setContentType("application/vnd.ms-excel;charset=utf-8");
            response.setHeader("Content-Disposition", "attachment;filename=" + tableName + ".xls");
            response.setCharacterEncoding("UTF-8");
            response.setHeader("Access-Control-Allow-Origin", "*");
            ServletOutputStream out = response.getOutputStream();
            bis = new BufferedInputStream(is);
            bos = new BufferedOutputStream(out);
            byte[] buff = new byte[2048];
            int bytesRead;
            while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
                bos.write(buff, 0, bytesRead);
            }
            response.flushBuffer();
        } catch (IOException e) {
            throw new RuntimeException("导出数据异常", e);
        } finally {
            try {
                bos.close();
                is.close();
                bis.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public static XSSFWorkbook initExcelWorkbook(List<String> firstRow) {
        XSSFWorkbook wb = new XSSFWorkbook();
        XSSFSheet sheet = wb.createSheet("fieldSheet");
        sheet.setAutobreaks(true);
        XSSFCellStyle setBorder = wb.createCellStyle();
//        setBorder.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        setBorder.setWrapText(true);
        XSSFRow row = sheet.createRow(0);

        //设置第一行的字段
        for (int i = 0; i < firstRow.size(); i++) {
            row.createCell(i).setCellValue(firstRow.get(i));
            sheet.autoSizeColumn(i);
        }
        return wb;
    }


    public static XSSFWorkbook exportExcel(List<LinkedHashMap> dataList, List<String> firstRow) {
        XSSFWorkbook wb = initExcelWorkbook(firstRow);
        XSSFSheet sheet = wb.getSheet("fieldSheet");
        for (int i = 0; i < dataList.size(); i++) {
            XSSFRow row = sheet.createRow(i + 1);
            LinkedHashMap<String, Object> data = dataList.get(i);
            for (int j = 0; j < firstRow.size(); j++) {
                String fieldName = firstRow.get(j);
                String value = "";
                if (data.get(fieldName) != null) {
                    value = String.valueOf(data.get(fieldName));
                }
                row.createCell(j).setCellValue(value);
            }
        }
        for (int i = 0; i < firstRow.size(); i++) {
            sheet.autoSizeColumn(i);
        }
        return wb;
    }

    /**
     *@desc 用于生成Excel枚举值下拉框（2022-09-20easypoi架包采用4.4改方法做出调整）
     *@param workbook 导出的excel
     *@param strings  枚举值数组
     *@param colNum  生成下拉框的列
     *@author maBing
     *@date 2022/9/20:10:33
     */
    public static void setDataValidation(Workbook workbook, String[] strings, int colNum) {
        /**4.1架包适用*/
        /*DVConstraint constraint = DVConstraint.createExplicitListConstraint(strings);
        CellRangeAddressList region = new CellRangeAddressList(1,100,colNum,colNum);
        HSSFDataValidation hssfDataValidation = new HSSFDataValidation(region,constraint);
        hssfDataValidation.setSuppressDropDownArrow(false);
        workbook.getSheetAt(0).addValidationData(hssfDataValidation);*/

        /**架包采用4.4改动*/
        CellRangeAddressList regions = new CellRangeAddressList(1,1200,colNum,colNum);
        /*XSSFDataValidation xssfDataValidation = new XSSFDataValidation(region,constraint);*/
        Sheet sheet = workbook.getSheetAt(0);
        DataValidationHelper helper = sheet.getDataValidationHelper();
        DataValidationConstraint constraint = helper.createExplicitListConstraint(strings);
        DataValidation dataValidation = helper.createValidation(constraint, regions);
        sheet.addValidationData(dataValidation);
    }


    public static void setDataValidation(Workbook workbook,String sheetName,int sheetIndex,int colIndex,String[] strings){
        selectListMore(sheetName,sheetIndex,workbook,colIndex,colIndex,strings);
    }


    public static void selectListMore(String sheetName, Integer index, Workbook workbook, int firstCol, int lastCol, String[] strings ){

        //将下拉框数据放到新的sheet里，然后excle通过新的sheet数据加载下拉框数据
        Sheet hidden = workbook.createSheet(sheetName);

        //创建单元格对象
        Cell cell =null;
        //遍历我们上面的数组，将数据取出来放到新sheet的单元格中
        for (int i = 0, length = strings.length; i < length; i++){
            //取出数组中的每个元素
            String name = strings[i];
            //根据i创建相应的行对象（说明我们将会把每个元素单独放一行）
            Row row = hidden.createRow(i);
            //创建每一行中的第一个单元格
            cell = row.createCell(0);
            //然后将数组中的元素赋值给这个单元格
            cell.setCellValue(name);
        }
        // 创建名称，可被其他单元格引用
        Name namedCell = workbook.createName();
        namedCell.setNameName(sheetName);
        // 设置名称引用的公式
        namedCell.setRefersToFormula(sheetName+"!$A$1:$A$" + strings.length);
        /*//加载数据,将名称为hidden的sheet中的数据转换为List形式
        DVConstraint constraint = DVConstraint.createFormulaListConstraint(sheetName);
        // 设置第一列的3-65534行为下拉列表
        // (3, 65534, 2, 2) ====> (起始行,结束行,起始列,结束列)
        CellRangeAddressList regions = new CellRangeAddressList(0, 65535, firstCol, lastCol);
        // 将设置下拉选的位置和数据的对应关系 绑定到一起
        DataValidation dataValidation = new HSSFDataValidation(regions, constraint);
        //将第二个sheet设置为隐藏
        workbook.setSheetHidden(index, true);
        //将数据赋给下拉列表
        workbook.getSheetAt(0).addValidationData(dataValidation);*/

        /**架包采用4.4改动*/
        CellRangeAddressList regions = new CellRangeAddressList(1,1200,firstCol,lastCol);
        /*XSSFDataValidation xssfDataValidation = new XSSFDataValidation(region,constraint);*/
        Sheet sheet = workbook.getSheetAt(0);
        DataValidationHelper helper = sheet.getDataValidationHelper();
        DataValidationConstraint constraint = helper.createExplicitListConstraint(strings);
        DataValidation dataValidation = helper.createValidation(constraint, regions);
        sheet.addValidationData(dataValidation);

    }


}