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  • poi excel

    使用apache的poi包可以对excel进行操作读取和写入。

    因excel分为xls的2003版和xlsx的2007版,poi在创建workbook时使用不同的类创建,因此需要注意区分xls。

    Workbook workbook = null;
    String fileExtension=FilenameUtils.getExtension(file.getOriginalFilename());
    if(".xls".equals(fileExtension)){
        workbook  = new HSSFWorkbook(file.getInputStream()); //2003 xls
    }else{
         workbook  = new XSSFWorkbook(file.getInputStream());  //2007 xlsx
    }

    ※注意如果引入poi后找不到XSSFWorkbook,则可能没有引入poi-ooxml.jar

    Sheet sheetWorkInfo = workbook.getSheet([sheetname]);

    以下为读取excel内容装入到list<bean>中的实例:

    /**
     * ExcelUtils 读取信息
     * @author DennyZhao
     *
     */
    public class ExcelUtils {
        
        /**
         * 获取workbook
         * @param file
         * @return workbook
         * @throws IOException 
         * @throws FileNotFoundException 
         */
        public static Workbook getWorkBook(String filepath) throws FileNotFoundException, IOException {
            Workbook workbook = null;
            File file = new File(filepath);
            /**
             * 文件是否存在,是否为可用文件
             */
            if(!file.exists() || file.isDirectory()) {
                System.out.println("file is not exists or is a directory...");
                return null;
            }
            /**
             * 文件是否可读
             */
            if(!file.canRead()) {
                System.out.println("the file can not be readed, please confirm if you have the authority to read it.");
                return null;
            }
            /**
             * 是否为excel文件
             */
            if(!FilenameUtils.getExtension(filepath).contains("xls")) {
                System.out.println("i'm so sorry..we just support  the file of type which is excel..");
                return null;
            }
            
            String fileExtension=FilenameUtils.getExtension(file.getName());
            if("xls".equals(fileExtension)){
                workbook  = new HSSFWorkbook(new FileInputStream(file)); //2003 xls
            }else{
                 workbook  = new XSSFWorkbook(new FileInputStream(file));  //2007 xlsx
            }
            return workbook;
        }
        
        /**
         * 读取数据返回对象一览
         * @param filepath
         * @param sheetName
         * @return
         * @throws IOException 
         * @throws FileNotFoundException 
         * @throws InvocationTargetException 
         * @throws IllegalAccessException 
         * @throws InstantiationException 
         */
        public static <T> List<T> getListObj(String filepath, String sheetName, Class<T> class1) throws FileNotFoundException, IOException, IllegalAccessException, InvocationTargetException, InstantiationException{
            Workbook work = getWorkBook(filepath);
            Sheet sheet = work.getSheet(sheetName);
            int rowCount = sheet.getPhysicalNumberOfRows();
            int colCount = sheet.getRow(0).getPhysicalNumberOfCells();
            List<T> listResult = new ArrayList<T>();
            
            for(int i=1;i < rowCount; i++) {
                Row row = sheet.getRow(i);
                Map<String, Object> map = new HashMap<String, Object>();
                // 判断是否已经读取完毕,第一格不能为空
                if(row.getCell(0)== null) {
                    break;
                }
                
                for(int j=0; j < colCount; j++) {
                    Cell cell = row.getCell(j);
                    String key = sheet.getRow(0).getCell(j).getStringCellValue();
                    
                    Object cellValue = getCellValue(cell);
                    map.put(key, cellValue);
                }
                T t = class1.newInstance();
                BeanUtils.copyProperties(t, map);
                listResult.add(t);
            }
            work.close();
            return listResult;
        }
    
        /**
         * 获取cellValue
         * @param cell
         */
        private static Object getCellValue(Cell cell) {
            if(cell == null) {
                return "";
            }
            CellType cellType = cell.getCellTypeEnum();
            Object obj = null;
            switch(cellType) {
            case NUMERIC:
                obj = cell.getNumericCellValue();
                break;
            default:
                obj = cell.getStringCellValue(); 
            }
            return obj;
        }
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  • 原文地址:https://www.cnblogs.com/DennyZhao/p/8464762.html
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