POIUtils 读取 poi （ui 上传解析）

用于解决在UI 上 上传excel , 然后解析

依赖：

    <!-- ############ poi ##############  -->
         <dependency>
             <groupId>org.apache.poi</groupId>
             <artifactId>poi</artifactId>
             <version>3.17</version>
         </dependency>
         
         <dependency>
             <groupId>org.apache.poi</groupId>
             <artifactId>poi-ooxml</artifactId>
             <version>3.17</version>
         </dependency>
         
         <dependency>
             <groupId>org.apache.poi</groupId>
             <artifactId>poi-ooxml-schemas</artifactId>
             <version>3.17</version>
         </dependency>

                  <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>        

 POIUtils:

package com.sea.shan.utils;

import static org.hamcrest.CoreMatchers.nullValue;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.security.interfaces.RSAMultiPrimePrivateCrtKey;
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.DataFormatter;
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.slf4j.LoggerFactory;
import org.springframework.web.multipart.MultipartFile;
/**
 * *************************************************************************
 * <PRE>
 *  @ClassName:    : POIUtils 
 *
 *  @Description:    : 
 *
 *  @Creation Date   : 23 Apr 2019 2:38:24 PM
 *
 *  @Author          :  Sea
 *  
 *
 * </PRE>
 **************************************************************************
 */
public class POIUtils {
    private static org.slf4j.Logger logger  = LoggerFactory.getLogger(POIUtils.class);
    private final static String xls = "xls";
    private final static String xlsx = "xlsx";
    
    /**
     * 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;
    }
    
    
    /**
     * 
     * @param file
     * @throws IOException
     */
    public static void checkFile(MultipartFile file) throws IOException{
        //判断文件是否存在
        if(null == file){
            logger.error("文件不存在！");
            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)){
            logger.error(fileName + "不是excel文件");
            throw new IOException(fileName + "不是excel文件");
        }
    }
    
    
    
    /**
     * 
     * @param file
     * @return
     */
    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) {
            logger.info(e.getMessage());
        }
        return workbook;
    }
    
    
    
    /**
     * 
     * @param filePath
     * @return
     */
    public static Workbook getWorkBook(String  filePath) {
        //获得文件名
        String fileName = filePath;
        
        logger.error("file name is : {}",fileName);
        //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
            FileInputStream is = new FileInputStream(filePath);
            //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) {
            logger.info(e.getMessage());
        }
        return workbook;
    }
    
    
    private static DataFormatter dataFormatter =null;
    static {
         dataFormatter = new DataFormatter();
    }
    /**
     * POI new AIP ,it can change all stype cell value  to String 
     * @param cell
     * @return
     */
    public static String getCellValues(Cell cell){
        String cellValue = dataFormatter.formatCellValue(cell);
        return cellValue;
    }
    
    /**
     * 
     * @param cell
     * @return
     */
    public static String getCellValue(Cell cell){
        String cellValue = "";
        if(cell == null){
            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;
    }
}

test:

package com.sea.shan.poi;

import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.junit.Test;

import com.sea.shan.utils.POIUtils;

public class POIUtilsTest {

    @Test
    public void testName() throws Exception {
        Workbook workBook = POIUtils.getWorkBook("/home/sea/Desktop/Test/airline-airport-country-code.xlsx");

        Sheet sheetAt0 = workBook.getSheetAt(0);
        int lastRowNum = sheetAt0.getLastRowNum();

        for (int i = 1; i <= lastRowNum; i++) {
            // get per row
            Row row = sheetAt0.getRow(i);
            
            if(row==null){
                continue;
            }
            
//            String cellValue0 = POIUtils.getCellValue(row.getCell(0));
//            String cellValue1 = POIUtils.getCellValue(row.getCell(1));
//            String cellValue0 = POIUtils.getCellValues(row.getCell(0));
//            String cellValue1 = POIUtils.getCellValues(row.getCell(1));
            String cellValue0 = new DataFormatter().formatCellValue(row.getCell(0));
            
            String cellValue1 = new DataFormatter().formatCellValue(row.getCell(1));
            
            System.err.println(cellValue0+"="+cellValue1);
            
        }
    }
}