poi技术实现excel的操作

poi技术简介

Apache POI是用Java编写的免费开源的跨平台的Java API，Apache POI提供API给Java程序对Microsoft Office格式档案读和写的功能，其中使用最多的就是使用POI操作Excel文件

poi依赖

 <dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.14</version>
  </dependency>

poi结构

HSSF －提供读写Microsoft Excel XLS格式档案的功能
XSSF －提供读写Microsoft Excel OOXML XLSX格式档案的功能
HWPF －提供读写Microsoft Word DOC格式档案的功能
HSLF －提供读写Microsoft PowerPoint格式档案的功能
HDGF －提供读Microsoft Visio格式档案的功能
HPBF －提供读Microsoft Publisher格式档案的功能
HSMF －提供读Microsoft Outlook格式档案的功能

从Excel表中读文件

创建readExcel类

public class ReadExcel {
    
    

    public void ReadExcel() throws Exception {
    
    
        // 创建输入流对象，把指定的excel文件放入流中
        File file = new File("D:/develop/IDEA/javaUp/poi_Excel/person.xls");
        FileInputStream fis =  new FileInputStream(file);
        // 创建一个HSSFWorkbook 对象  xls文档对象
        HSSFWorkbook workbook = new HSSFWorkbook(fis);
        // 找到指定的工作簿对象
        HSSFSheet sheet = workbook.getSheetAt(0);
        // 找到最后一行的行号，用作循环
        int lastRowNum = sheet.getLastRowNum();
        for (int i = 1; i <lastRowNum ; i++) {
    
    
            // 获取指定的行对象
            HSSFRow row = sheet.getRow(i);
            int id = (int) row.getCell(0).getNumericCellValue();
            String name = row.getCell(1).getStringCellValue();
            String gender = row.getCell(2).getStringCellValue();
            int age = (int) row.getCell(3).getNumericCellValue();
            Date birthday = row.getCell(4).getDateCellValue();
            System.out.println(id+"\t"+name+"\t"+gender+"\t"+age+"\t"+birthday);
        }
        // 关闭资源
        workbook.close();
        fis.close();

    }
}

调用测试获取成功

@org.junit.Test
public void test() throws Exception {
    
    
    ReadExcel readExcel = new ReadExcel();
    readExcel.ReadExcel();
}

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往Excel表中写文件

创建writeExcel类

public class WriteExcel {
    
    

    public void writeExcel() throws Exception{
    
    

        // 创建HSSFWorkbook对象
        HSSFWorkbook workbook = new HSSFWorkbook();
        // 创建工作簿对象
        HSSFSheet sheet = workbook.createSheet("学生表");
        // 创建标题行
        HSSFRow row0 = sheet.createRow(0);
        row0.createCell(0).setCellValue("姓名");
        row0.createCell(1).setCellValue("年龄");
        row0.createCell(2).setCellValue("住址");
        row0.createCell(3).setCellValue("爱好");

        // 创建内容行
        HSSFRow row1 = sheet.createRow(1);
        row1.createCell(0).setCellValue("张三");
        row1.createCell(1).setCellValue(23);
        row1.createCell(2).setCellValue("上海");
        row1.createCell(3).setCellValue("篮球");

        HSSFRow row2 = sheet.createRow(2);
        row2.createCell(0).setCellValue("李四");
        row2.createCell(1).setCellValue(25);
        row2.createCell(2).setCellValue("北京");
        row2.createCell(3).setCellValue("足球");

        // 写入数据
        workbook.write(new FileOutputStream("D:/develop/IDEA/javaUp/poi_Excel/student.xls"));

        // 关闭资源
        workbook.close();
    }
}

调用测试

@org.junit.Test
public void test1() throws Exception {
    
    
    WriteExcel writeExcel = new WriteExcel();
    writeExcel.writeExcel();
}

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工具类

package com.chenshuang.util;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.multipart.MultipartFile;

public class POIUtils {
    
    
    private final static String xls = "xls";
    private final static String xlsx = "xlsx";
    private final static String DATE_FORMAT = "yyyy/MM/dd";
    /**
     * 读入excel文件，解析后返回
     * @param file
     * @throws IOException
     */
    public static List<String[]> readExcel(MultipartFile file) throws IOException {
    
    
        //检查文件
        checkFile(file);
        //获得Workbook工作薄对象
        Workbook workbook = getWorkBook(file);
        //创建返回对象，把每行中的值作为一个数组，所有行作为一个集合返回
        List<String[]> list = new ArrayList<String[]>();
        if(workbook != null){
    
    
            for(int sheetNum = 0;sheetNum < workbook.getNumberOfSheets();sheetNum++){
    
    
                //获得当前sheet工作表
                Sheet sheet = workbook.getSheetAt(sheetNum);
                if(sheet == null){
    
    
                    continue;
                }
                //获得当前sheet的开始行
                int firstRowNum  = sheet.getFirstRowNum();
                //获得当前sheet的结束行
                int lastRowNum = sheet.getLastRowNum();
                //循环除了第一行的所有行
                for(int rowNum = firstRowNum+1;rowNum <= lastRowNum;rowNum++){
    
    
                    //获得当前行
                    Row row = sheet.getRow(rowNum);
                    if(row == null){
    
    
                        continue;
                    }
                    //获得当前行的开始列
                    int firstCellNum = row.getFirstCellNum();
                    //获得当前行的列数
                    int lastCellNum = row.getPhysicalNumberOfCells();
                    String[] cells = new String[row.getPhysicalNumberOfCells()];
                    //循环当前行
                    for(int cellNum = firstCellNum; cellNum < lastCellNum;cellNum++){
    
    
                        Cell cell = row.getCell(cellNum);
                        cells[cellNum] = getCellValue(cell);
                    }
                    list.add(cells);
                }
            }
            workbook.close();
        }
        return list;
    }

    //校验文件是否合法
    public static void checkFile(MultipartFile file) throws IOException{
    
    
        //判断文件是否存在
        if(null == file){
    
    
            throw new FileNotFoundException("文件不存在！");
        }
        //获得文件名
        String fileName = file.getOriginalFilename();
        //判断文件是否是excel文件
        if(!fileName.endsWith(xls) && !fileName.endsWith(xlsx)){
    
    
            throw new IOException(fileName + "不是excel文件");
        }
    }
    public static Workbook getWorkBook(MultipartFile file) {
    
    
        //获得文件名
        String fileName = file.getOriginalFilename();
        //创建Workbook工作薄对象，表示整个excel
        Workbook workbook = null;
        try {
    
    
            //获取excel文件的io流
            InputStream is = file.getInputStream();
            //根据文件后缀名不同(xls和xlsx)获得不同的Workbook实现类对象
            if(fileName.endsWith(xls)){
    
    
                //2003
                workbook = new HSSFWorkbook(is);
            }else if(fileName.endsWith(xlsx)){
    
    
                //2007
                workbook = new XSSFWorkbook(is);
            }
        } catch (IOException e) {
    
    
            e.printStackTrace();
        }
        return workbook;
    }
    public static String getCellValue(Cell cell){
    
    
        String cellValue = "";
        if(cell == null){
    
    
            return cellValue;
        }
        //如果当前单元格内容为日期类型，需要特殊处理
        String dataFormatString = cell.getCellStyle().getDataFormatString();
        if(dataFormatString.equals("m/d/yy")){
    
    
            cellValue = new SimpleDateFormat(DATE_FORMAT).format(cell.getDateCellValue());
            return cellValue;
        }
        //把数字当成String来读，避免出现1读成1.0的情况
        if(cell.getCellType() == Cell.CELL_TYPE_NUMERIC){
    
    
            cell.setCellType(Cell.CELL_TYPE_STRING);
        }
        //判断数据的类型
        switch (cell.getCellType()){
    
    
            case Cell.CELL_TYPE_NUMERIC: //数字
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            case Cell.CELL_TYPE_STRING: //字符串
                cellValue = String.valueOf(cell.getStringCellValue());
                break;
            case Cell.CELL_TYPE_BOOLEAN: //Boolean
                cellValue = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_FORMULA: //公式
                cellValue = String.valueOf(cell.getCellFormula());
                break;
            case Cell.CELL_TYPE_BLANK: //空值
                cellValue = "";
                break;
            case Cell.CELL_TYPE_ERROR: //故障
                cellValue = "非法字符";
                break;
            default:
                cellValue = "未知类型";
                break;
        }
        return cellValue;
    }
}

案例

往服务器的文件中些信息

    // 创建输入流对象，把指定的excel文件放入流中--【文件再服务器的本地位置】
    File file = new File("D:\\develop\\IDEA\\javaUp\\pro\\chenshuangpe_parent\\chenshuangpe_controller\\src\\main\\resources\\static\\template\\report_template.xlsx");
    FileInputStream fis = new FileInputStream(file);
    // 创建一个XSSFWorkbook 对象  xlsx文档对象
    XSSFWorkbook workbook = new XSSFWorkbook(fis);

    XSSFSheet sheet = workbook.getSheet("data");
    XSSFRow row2 = sheet.getRow(2);
    row2.getCell(5).setCellValue(nowDate);
    XSSFRow row4 = sheet.getRow(4);
    row4.getCell(5).setCellValue(todayNewMember);
    row4.getCell(7).setCellValue(totalMember);
    XSSFRow row5 = sheet.getRow(5);
    row5.getCell(5).setCellValue(thisWeekNewMember);
    row5.getCell(7).setCellValue(thisMonthNewMember);
    XSSFRow row7 = sheet.getRow(7);
    row7.getCell(5).setCellValue(todayOrderNumber);
    row7.getCell(7).setCellValue(todayVisitsNumber);
    XSSFRow row8 = sheet.getRow(8);
    row8.getCell(5).setCellValue(thisWeekOrderNumber);
    row8.getCell(7).setCellValue(thisWeekVisitsNumber);
    XSSFRow row9 = sheet.getRow(9);
    row9.getCell(5).setCellValue(thisMonthOrderNumber);
    row9.getCell(7).setCellValue(thisMonthVisitsNumber);

    // -----------------写入热门套餐

    for (int i = 0; i < hotSetmeal.size(); i++) {
    
    
        Map map = hotSetmeal.get(i);
        String name = (String) map.get("name");
        String code = (String) map.get("code");
        
        XSSFRow rowS1 = sheet.getRow(12 + i);
        rowS1.getCell(4).setCellValue(name);
        rowS1.getCell(5).setCellValue(map.get("setmeal_count").toString());
        rowS1.getCell(6).setCellValue(code);
        rowS1.getCell(7).setCellValue(map.get("proportion").toString());
    }
    // 写入文件
    workbook.write(new FileOutputStream(file));
    workbook.close();
    fis.close();

从服务器下载

前端

methods:{
    exportExcel(){
        window.location.href = '/report/exportBusinessReport';
    }
}

后端业务

//        ------------------------- 写数据  ----------------------
        {
    
    
            // 创建输入流对象，把指定的excel文件放入流中
            File file = new File("D:\\develop\\IDEA\\javaUp\\pro\\chenshuangpe_parent\\chenshuangpe_controller\\src\\main\\resources\\static\\template\\report_template.xlsx");
            FileInputStream fis = new FileInputStream(file);
            // 创建一个XSSFWorkbook 对象  xlsx文档对象
            XSSFWorkbook workbook = new XSSFWorkbook(fis);

            XSSFSheet sheet = workbook.getSheet("data");
            XSSFRow row2 = sheet.getRow(2);
            row2.getCell(5).setCellValue(nowDate);
            XSSFRow row4 = sheet.getRow(4);
            row4.getCell(5).setCellValue(todayNewMember);
            row4.getCell(7).setCellValue(totalMember);
            XSSFRow row5 = sheet.getRow(5);
            row5.getCell(5).setCellValue(thisWeekNewMember);
            row5.getCell(7).setCellValue(thisMonthNewMember);
            XSSFRow row7 = sheet.getRow(7);
            row7.getCell(5).setCellValue(todayOrderNumber);
            row7.getCell(7).setCellValue(todayVisitsNumber);
            XSSFRow row8 = sheet.getRow(8);
            row8.getCell(5).setCellValue(thisWeekOrderNumber);
            row8.getCell(7).setCellValue(thisWeekVisitsNumber);
            XSSFRow row9 = sheet.getRow(9);
            row9.getCell(5).setCellValue(thisMonthOrderNumber);
            row9.getCell(7).setCellValue(thisMonthVisitsNumber);

            // -----------------写入热门套餐

            for (int i = 0; i < hotSetmeal.size(); i++) {
    
    
                Map map = hotSetmeal.get(i);
                String name = (String) map.get("name");
                String code = (String) map.get("code");

                XSSFRow rowS1 = sheet.getRow(12 + i);
                rowS1.getCell(4).setCellValue(name);
                rowS1.getCell(5).setCellValue(map.get("setmeal_count").toString());
                rowS1.getCell(6).setCellValue(code);
                rowS1.getCell(7).setCellValue(map.get("proportion").toString());
            }
            // 写入文件
            workbook.write(new FileOutputStream(file));
            workbook.close();
            fis.close();
        }
name);
                rowS1.getCell(5).setCellValue(map.get("setmeal_count").toString());
                rowS1.getCell(6).setCellValue(code);
                rowS1.getCell(7).setCellValue(map.get("proportion").toString());
            }
            // 写入文件
            workbook.write(new FileOutputStream(file));
            workbook.close();
            fis.close();
        }

如何利用poi技术操作Excel表格？