[开发工具]Java操作Excel文件

Java操作Excel文件

0.添加依赖

        <!--excel process tool-->
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.1.0</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.1.0</version>
        </dependency>

1. excelToObjectModel

    public static List<Cigarette> excelToObjectModel(){
        List<Map<String,String>> list = getAllCell();
        List<Cigarette> itemList = new ArrayList<>();
        for (Map<String,String> map : list) {
            String sellerId = null;
            String sellerName = null;
            String cigaretteName = null;
            String priceString = null;
            String orderNumString = null;
            String type = null;

            for (Map.Entry<String, String> entry : map.entrySet()) {
                switch (entry.getKey()){
                    case "1" : sellerId = entry.getValue();
                    case "2" : sellerName = entry.getValue();
                    case "3" : cigaretteName = entry.getValue();
                    case "4" : orderNumString  = entry.getValue();
                    case "5" : priceString = entry.getValue();
                    case "6" : type = entry.getValue();
                    default: break;
                }
            }
            assert priceString !=null;
            int price = (int)Float.parseFloat(priceString);
            assert orderNumString !=null;
            int orderNum = (int)Float.parseFloat(orderNumString);
            if(orderNum == 0){
                continue;
            }
            if("".equals(type)){
                continue;
            }
            itemList.add(new Cigarette(sellerId, sellerName, cigaretteName,price
                    ,orderNum,type));
        }
        return itemList;

    }

2. getAllCell

    public static List<Map<String,String>> getAllCell(){
        Workbook wb;
        Sheet sheet;
        Row row;
        List<Map<String,String>> list = null;
        String cellData;
        String[] columns = new String[COLUMN_NUMS];
        for (int i = 0; i < COLUMN_NUMS; i++) {
            columns[i] = i+1+"";
        }
        wb = readExcel();
        if(wb != null){
            //用来存放表中数据
            list = new ArrayList<>();
            //获取第一个sheet
            sheet = wb.getSheetAt(SHEET_NUM - 1 );
            //获取最大行数
            int rownum = sheet.getPhysicalNumberOfRows();
            //获取第一行
            row = sheet.getRow(0);
            //获取最大列数
            int colnum = row.getPhysicalNumberOfCells();
            for (int i = 1; i<rownum; i++) {
                Map<String,String> map = new LinkedHashMap<>();
                row = sheet.getRow(i);
                if(row !=null){
                    for (int j=0;j<colnum;j++){
                        cellData = (String) getCellFormatValue(row.getCell(j));
                        map.put(columns[j], cellData);
                    }
                }else{
                    break;
                }
                list.add(map);
            }
        }
        return list;
    }

    public static Workbook readExcel(){
        Workbook wb = null;
        String extString = PATH.substring(PATH.lastIndexOf("."));
        InputStream is;
        try {
            is = new FileInputStream(PATH);
            if(".xls".equals(extString)){
                return wb = new HSSFWorkbook(is);
            }else if(".xlsx".equals(extString)){
                return wb = new XSSFWorkbook(is);
            }else{
                return wb = null;
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return wb;
    }

   

3. getCellFormatValue

 public static Object getCellFormatValue(Cell cell){
        Object cellValue;
        if(cell!=null){
            //判断cell类型
            switch(cell.getCellType()){
                case NUMERIC:{
                    cellValue = String.valueOf(cell.getNumericCellValue());
                    break;
                }
                case FORMULA:{
                    //判断cell是否为日期格式
                    if(DateUtil.isCellDateFormatted(cell)){
                        //转换为日期格式YYYY-mm-dd
                        cellValue = cell.getDateCellValue();
                    }else{
                        //数字
                        cellValue = String.valueOf(cell.getNumericCellValue());
                    }
                    break;
                }
                case STRING:{
                    cellValue = cell.getRichStringCellValue().getString();
                    break;
                }
                default:
                    cellValue = "";
            }
        }else{
            cellValue = "";
        }
        return cellValue;
    }