import java.lang.annotation.ElementType;

import java.lang.annotation.Retention;

import java.lang.annotation.RetentionPolicy;

import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)

@Target(ElementType.FIELD)

public @interface ExcelAttribute {

    /** 对应的列名称 */

    String name() default "";

    /** 列序号 */

    int sort();

    /** 字段类型对应的格式 */

    String format() default "";

}

package com.ihrm.common.poi.utils;

import com.ihrm.domain.poi.ExcelAttribute;

import org.apache.poi.hssf.usermodel.*;

import org.apache.poi.poifs.filesystem.POIFSFileSystem;

import org.apache.poi.ss.format.CellFormat;

import org.apache.poi.ss.usermodel.Cell;

import org.apache.poi.ss.usermodel.DateUtil;

import org.apache.poi.ss.usermodel.Row;

import org.apache.poi.ss.usermodel.Sheet;

import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileInputStream;

import java.io.InputStream;

import java.lang.reflect.Field;

import java.math.BigDecimal;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.ArrayList;

import java.util.Date;

import java.util.List;

public class ExcelImportUtil<T> {

    private Class clazz;

    private  Field fields[];

    public ExcelImportUtil(Class clazz) {

        this.clazz = clazz;

        fields = clazz.getDeclaredFields();

    }

    /**

     * 基于注解读取excel

     */

    public List<T> readExcel(InputStream is, int rowIndex,int cellIndex) {

        List<T> list = new ArrayList<T>();

        T entity = null;

        try {

            XSSFWorkbook workbook = new XSSFWorkbook(is);

            Sheet sheet = workbook.getSheetAt(0);

            // 不准确

            int rowLength = sheet.getLastRowNum();

            System.out.println(sheet.getLastRowNum());

            for (int rowNum = rowIndex; rowNum <= sheet.getLastRowNum(); rowNum++) {

                Row row = sheet.getRow(rowNum);

                entity = (T) clazz.newInstance();

                System.out.println(row.getLastCellNum());

                for (int j = cellIndex; j < row.getLastCellNum(); j++) {

                    Cell cell = row.getCell(j);

                    for (Field field : fields) {

                        if(field.isAnnotationPresent(ExcelAttribute.class)){

                            field.setAccessible(true);

                            ExcelAttribute ea = field.getAnnotation(ExcelAttribute.class);

                            if(j == ea.sort()) {

                                field.set(entity, covertAttrType(field, cell));

                            }

                        }

                    }

                }

                list.add(entity);

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

        return list;

    }

    /**

     * 类型转换 将cell 单元格格式转为 字段类型

     */

    private Object covertAttrType(Field field, Cell cell) throws Exception {

        String fieldType = field.getType().getSimpleName();

        if ("String".equals(fieldType)) {

            return getValue(cell);

        }else if ("Date".equals(fieldType)) {

            return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").parse(getValue(cell)) ;

        }else if ("int".equals(fieldType) || "Integer".equals(fieldType)) {

            return Integer.parseInt(getValue(cell));

        }else if ("double".equals(fieldType) || "Double".equals(fieldType)) {

            return Double.parseDouble(getValue(cell));

        }else {

            return null;

        }

    }

    /**

     * 格式转为String

     * @param cell

     * @return

     */

    public String getValue(Cell cell) {

        if (cell == null) {

            return "";

        }

        switch (cell.getCellType()) {

            case STRING:

                return cell.getRichStringCellValue().getString().trim();

            case NUMERIC:

                if (DateUtil.isCellDateFormatted(cell)) {

                    Date dt = DateUtil.getJavaDate(cell.getNumericCellValue());

                    return new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(dt);

                } else {

                    // 防止数值变成科学计数法

                    String strCell = "";

                    Double num = cell.getNumericCellValue();

                    BigDecimal bd = new BigDecimal(num.toString());

                    if (bd != null) {

                        strCell = bd.toPlainString();

                    }

                    // 去除 浮点型 自动加的 .0

                    if (strCell.endsWith(".0")) {

                        strCell = strCell.substring(0, strCell.indexOf("."));

                    }

                    return strCell;

                }

            case BOOLEAN:

                return String.valueOf(cell.getBooleanCellValue());

            default:

                return "";

        }

    }

}

import lombok.AllArgsConstructor;

import lombok.Data;

import lombok.NoArgsConstructor;

import javax.persistence.Entity;

import javax.persistence.Id;

import javax.persistence.Table;

import java.io.Serializable;

import java.util.Date;

//转正申请

@Entity

@Table(name = "em_positive")

@Data

@AllArgsConstructor

@NoArgsConstructor

public class EmployeePositive implements Serializable {

    private static final long serialVersionUID = 2391824518947910773L;

    /**

     * 员工ID

     */

    @Id

    private String userId;

    /**

     * 转正日期

     */

     @ExcelAttribute(sort=1)

    private Date dateOfCorrection;

    /**

     * 转正评价

     */

      @ExcelAttribute(sort=2)

    private String correctionEvaluation;

    /**

     * 附件

     */

    private String enclosure;

    /**

     * 单据状态 1是未执行，2是已执行

     */

    private Integer estatus;

    /**

     * 创建时间

     */

    private Date createTime;

}