Maven项目结合POI实现导入导入导入导入导入Excl…

2018-08-14 09:55:31来源：博客园阅读 ()

第一步：写入maven依赖（3.6是比较稳定的版本，可用于生产环境）

     <!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.6</version>
        </dependency>

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.6</version>
        </dependency>

第二步：将Excl导入工具类加进项目中，开箱即用，内置测试main（）方法

import org.apache.poi.hssf.usermodel.HSSFDateUtil;
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 java.io.File;
import java.io.FileInputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;


/**
 *
 * @ClassName: ImportExcelUtil
 * @Description: excel 导入数据
 * @author JonyChen
 * @date 2018年8月13日
 * @time 上午10:28:48
 */
public class ImportExcelUtil {

    private final static String excel2003L =".xls";    //2003- 版本的excel
    private final static String excel2007U =".xlsx";   //2007+ 版本的excel

    /**
     * 描述：获取IO流中的数据，组装成List<List<Object>>对象
     * @param file
     * @return
     * @throws Exception
     */
    public  List<List<Object>> importExcel(File file) throws Exception{
        List<List<Object>> list = null;

        //创建Excel工作薄
        Workbook work = this.getWorkbook(file);
        if(null == work){
            throw new Exception("创建Excel工作薄为空！");
        }
        Sheet sheet = null;
        Row row = null;
        Cell cell = null;

        list = new ArrayList<List<Object>>();
        //遍历Excel中所有的sheet
        for (int i = 0; i <work.getNumberOfSheets(); i++) {
            sheet = work.getSheetAt(i);
            if(sheet==null){continue;}

            //遍历当前sheet中的所有行
            for (int j = sheet.getFirstRowNum(); j <= sheet.getLastRowNum(); j++) {
                row = sheet.getRow(j);
                if(row==null||row.getFirstCellNum()==j){continue;}

                //遍历所有的列
                List<Object> li = new ArrayList<Object>();
                for (int y = row.getFirstCellNum(); y <row.getLastCellNum(); y++) {
                    cell = row.getCell(y);
                    li.add(this.getCellValue(cell));
                }
                list.add(li);
            }
        }
        return list;
    }

    /**
     * 描述：根据文件后缀，自适应上传文件的版本
     * @param file
     * @return
     * @throws Exception
     */
    public  Workbook getWorkbook(File file) throws Exception{
        Workbook wb = null;
        String fileType = file.getName().substring(file.getName().lastIndexOf("."));
        if(excel2003L.equals(fileType)){
            wb = new HSSFWorkbook(new FileInputStream(file));  //2003-
        }else if(excel2007U.equals(fileType)){
            wb = new XSSFWorkbook(new FileInputStream(file));  //2007+
        }else{
            throw new Exception("解析的文件格式有误！");
        }
        return wb;
    }

    /**
     * 描述：对表格中数值进行格式化
     * @param cell
     * @return
     */
    public  Object getCellValue(Cell cell){
        //用String接收所有返回的值
        String value = null;
        DecimalFormat df = new DecimalFormat("0");  //格式化number String字符
        SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd");  //日期格式化
        DecimalFormat df2 = new DecimalFormat("0.00");  //格式化数字

        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_STRING:  //String类型的数据
                value =  cell.getStringCellValue();
                break;

            case Cell.CELL_TYPE_NUMERIC:   //数值类型(取值用cell.getNumericCellValue() 或cell.getDateCellValue())
                if("General".equals(cell.getCellStyle().getDataFormatString())){
                    value = df.format(cell.getNumericCellValue());
                }else if(HSSFDateUtil.isCellDateFormatted(cell)){
                    value = sdf.format(HSSFDateUtil.getJavaDate(cell.getNumericCellValue()));
                }else{
                    value = df2.format(cell.getNumericCellValue());
                }
                break;

            case Cell.CELL_TYPE_BOOLEAN:  //Boolean类型
                value = String.valueOf(cell.getBooleanCellValue());
                break;


            case Cell.CELL_TYPE_FORMULA: //表达式类型
                value = String.valueOf(cell.getCellFormula());
                break;

            case Cell.CELL_TYPE_ERROR: //异常类型 不知道何时算异常
                value=String.valueOf(cell.getErrorCellValue());
                break;

            case Cell.CELL_TYPE_BLANK:  //空，不知道何时算空
                value = "";
                break;

            default:
                value = "";
                break;
        }
        if(value.equals("")||value==null){
            value = "";
        }
        if (cell == null) {
            return "";
        }
        return value;
    }

    //读取excel里的字段
    public static void main(String[] args){
        ImportExcelUtil importExcelUtil=new ImportExcelUtil();
        //excel 导入数据demo
        File file = new File("C:\\Users\\srt\\Desktop\\signup_category.xls");
        List<List<Object>> dataList= null;
        List<SignupCategory> list=new ArrayList<>();
        try {
            dataList = importExcelUtil.importExcel(file);
        } catch (Exception e) {
            e.printStackTrace();
        }
        //数据封装格式一，将表格中的数据遍历取出后封装进对象放进List
              for (int i = 0; i <dataList.size(); i++) {

                  Object type_id = dataList.get(i).get(0);
                  Object type_name = dataList.get(i).get(1);

                  SignupCategory signupCategory=new SignupCategory();
                  signupCategory.setTypeId(Integer.parseInt((String)type_id));
                  signupCategory.setTypeName((String)type_name);

                  list.add(signupCategory);

                  System.out.println("------------------");
                  System.out.println((String)type_id+":"+(String)type_name);
              }
              System.out.println(JsonUtils.toJson(list));
        //数据封装格式二，双重循环遍历取出元素
        /*for (int i = 0; i < dataList.size(); i++) {
            for (int j = 0; j < dataList.get(i).size(); j++) {
                System.out.println(dataList.get(i).get(j));
            }
            System.out.println("------------------");
        }*/
    }
}