Java集成POI进行Excele的导入导出,以及报错: java.lang.AbstractMethodError..........

报错信息如下

java.lang.AbstractMethodError: org.apache.poi.xssf.usermodel.XSSFCell.setCellType(Lorg/apache/poi/ss/usermodel/CellType;

首先项目集成POI进行导入导出的pom文件

注意:最开始我使用的是3.15和3.14,但是会产生上面的报错信息,我这边一直以为是我代码存在问题, 反复修改之后还是存在问题,最后翻墙查了下stackoverflow,感觉出错的原因是poi的版本过低,于是将这边都修改成下面的4.0.0,最后解决问题

https://stackoverflow.com/questions/39993683/alternative-to-deprecated-getcelltype

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.0.0</version>
        </dependency>

准备工作,将本地文件夹中的excel,准备好,修改demo中的地址

写入Excele的demo

package com.excel.demo.util;

import com.excel.demo.model.User;
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.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class WriteExcel {
    private static final String EXCEL_XLS = "xls";
    private static final String EXCEL_XLSX = "xlsx";

    public static void main(String[] args) {
//        ArrayList<String> strings = new ArrayList<>();
//        strings.add("1");
//        strings.add("2");
//        strings.add("3");
//        strings.add("4");
//        strings.add("5");
//        strings.add("6");
//        strings.add("7");
//        writeExcelToRow(strings, 3, "E:/writeExcel.xlsx");

        ArrayList<User> vos = new ArrayList<>();
        User user = new User();
        user.setAddress("地球村");
        user.setLove("喜洋ccccc洋");
        user.setAge(18);
        user.setName("张三");
        user.setSex(true);
        vos.add(user);
        vos.add(user);
        vos.add(user);
        vos.add(user);
        writeExcelVo(vos, "E:/writeExcel.xlsx");

    }

    //向Excel里存储对象
    public static void writeExcelVo(List<User> dataList, String finalXlsxPath) {
        OutputStream out = null;
        try {
            // 获取总列数
            int columnNumCount = dataList.size();
            // 读取Excel文档
            File finalXlsxFile = new File(finalXlsxPath);
            Workbook workBook = getWorkbok(finalXlsxFile);
            // sheet 对应一个工作页
            Sheet sheet = workBook.getSheetAt(0);
            /**
             * 删除原有数据，除了属性列
             */
            int rowNumber = sheet.getLastRowNum();    // 第一行从0开始算
            System.out.println("原始数据总行数，除属性列：" + rowNumber);
            for (int i = 1; i <= rowNumber; i++) {
                Row row = sheet.getRow(i);
                if(row==null){
                    continue;
                }
                sheet.removeRow(row);
            }
            // 创建文件输出流，输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out = new FileOutputStream(finalXlsxPath);
            workBook.write(out);
            /**
             * 往Excel中写新数据
             */
            for (int j = 0; j < dataList.size(); j++) {

                // 创建一行：从第二行开始，跳过属性列
                Row row = sheet.createRow(j + 1);
                // 得到要插入的每一条记录
                //TODO 下面可以进行优化,使用反射获取字段数量,然后对字段进行遍历,在存储,这样可以减少手写代码的量
                User user = dataList.get(j);

                // 在一行内循环
                Cell first = row.createCell(0);
                first.setCellValue(user.getName());

                Cell second = row.createCell(1);
                second.setCellValue(user.getAge());

                Cell third = row.createCell(2);
                third.setCellValue(user.getLove());

                Cell c4 = row.createCell(4);
                c4.setCellValue(user.getAddress());

                Cell c5 = row.createCell(5);
                c5.setCellValue(user.isSex());
            }
            // 创建文件输出流，准备输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out = new FileOutputStream(finalXlsxPath);
            workBook.write(out);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.flush();
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println("数据导出成功");
    }

    public static void writeExcel(List<Map> dataList, int cloumnCount, String finalXlsxPath) {
        OutputStream out = null;
        try {
            // 获取总列数
            int columnNumCount = cloumnCount;
            // 读取Excel文档
            File finalXlsxFile = new File(finalXlsxPath);
            Workbook workBook = getWorkbok(finalXlsxFile);
            // sheet 对应一个工作页
            Sheet sheet = workBook.getSheetAt(0);
            /**
             * 删除原有数据，除了属性列
             */
            int rowNumber = sheet.getLastRowNum();    // 第一行从0开始算
            System.out.println("原始数据总行数，除属性列：" + rowNumber);
            for (int i = 1; i <= rowNumber; i++) {
                Row row = sheet.getRow(i);
                if(row==null){
                    continue;
                }
                sheet.removeRow(row);
            }
            // 创建文件输出流，输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out = new FileOutputStream(finalXlsxPath);
            workBook.write(out);
            /**
             * 往Excel中写新数据
             */
            for (int j = 0; j < dataList.size(); j++) {
                // 创建一行：从第二行开始，跳过属性列
                Row row = sheet.createRow(j + 1);
                // 得到要插入的每一条记录
                Map dataMap = dataList.get(j);
                String name = dataMap.get("BankName").toString();
                String address = dataMap.get("Addr").toString();
                String phone = dataMap.get("Phone").toString();
                for (int k = 0; k <= columnNumCount; k++) {
                    // 在一行内循环
                    Cell first = row.createCell(0);
                    first.setCellValue(name);

                    Cell second = row.createCell(1);
                    second.setCellValue(address);

                    Cell third = row.createCell(2);
                    third.setCellValue(phone);
                }
            }
            // 创建文件输出流，准备输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out = new FileOutputStream(finalXlsxPath);
            workBook.write(out);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.flush();
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println("数据导出成功");
    }

    /**
     * 指定行里面添加数据
     *
     * @param dataList
     * @param rowNum
     * @param finalXlsxPath
     */
    public static void writeExcelToRow(List<String> dataList, int rowNum, String finalXlsxPath) {
        OutputStream out = null;
        try {
            // 获取总列数
            int columnNumCount = rowNum;
            // 读取Excel文档
            File finalXlsxFile = new File(finalXlsxPath);
            Workbook workBook = getWorkbok(finalXlsxFile);
            // sheet 对应一个工作页
            Sheet sheet = workBook.getSheetAt(0);
            /**
             * 删除原有数据，除了属性列
             */
            int rowNumber = sheet.getLastRowNum();    // 第一行从0开始算
            System.out.println("原始数据总行数，除属性列：" + rowNumber);
            for (int i = 1; i <= rowNumber; i++) {
                Row row = sheet.getRow(i);
                if(row==null){
                    continue;
                }
                sheet.removeRow(row);
            }
            // 创建文件输出流，输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out = new FileOutputStream(finalXlsxPath);
            workBook.write(out);
            /**
             * 往Excel中写新数据
             */
            Row row = sheet.createRow(columnNumCount);
            for (int j = 0; j < dataList.size(); j++) {
                // 创建一行：从第二行开始，跳过属性列
                // 得到要插入的每一条记录
                row.createCell(j).setCellValue(dataList.get(j));

            }
            // 创建文件输出流，准备输出电子表格：这个必须有，否则你在sheet上做的任何操作都不会有效
            out = new FileOutputStream(finalXlsxPath);
            workBook.write(out);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.flush();
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        System.out.println("数据导出成功");
    }

    /**
     * 判断Excel的版本,获取Workbook
     *
     * @param file
     * @return
     * @throws IOException
     */
    public static Workbook getWorkbok(File file) throws IOException {
        Workbook wb = null;
        FileInputStream in = new FileInputStream(file);
        if (file.getName().endsWith(EXCEL_XLS)) {     //Excel&nbsp;2003
            wb = new HSSFWorkbook(in);
        } else if (file.getName().endsWith(EXCEL_XLSX)) {    // Excel 2007/2010
            wb = new XSSFWorkbook(in);
        }
        return wb;
    }
}

读取Excel的demo

package com.excel.demo.util;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.text.DateFormat;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class ReadExcel {
    private static final String EXCEL_XLS = "xls";
    private static final String EXCEL_XLSX = "xlsx";

    public static void main(String[] args) {
        ReadExcel obj = new ReadExcel();
        File file = new File("E:/readExcel1.xls");
        List excelList = obj.readExcel(file);
        System.out.println("list中的数据打印出来");
        for (int i = 0; i < excelList.size(); i++) {
            List list = (List) excelList.get(i);
            for (int j = 0; j < list.size(); j++) {
                System.out.print(list.get(j));
            }
            System.out.println();
        }

    }

    // 去读Excel的方法readExcel，该方法的入口参数为一个File对象
    public List readExcel(File file) {
        try {
            // 创建输入流，读取Excel
            Workbook wb = getWorkbok(file);
            // Excel的页签数量
            int sheetSize = wb.getNumberOfSheets();
            for (int index = 0; index < sheetSize; index++) {
                List<List> outerList = new ArrayList<List>();
                // 每个页签创建一个Sheet对象
                Sheet sheet = wb.getSheetAt(index);
                // sheet.getLastRowNum()返回该页的总行数
                for (int i = 0; i < sheet.getLastRowNum(); i++) {
                    List innerList = new ArrayList();
                    // row.getPhysicalNumberOfCells()返回该页的总列数
                    Row row = sheet.getRow(i);
                    for (int j = 0; j < row.getPhysicalNumberOfCells(); j++) {
                        Cell cell = row.getCell(j);
                        String value = getCellValue(cell);
                        if (value.isEmpty()) {
                            continue;
                        }
                        innerList.add(value);
                        System.out.print(value + "\t");
                    }
                    outerList.add(i, innerList);
                    System.out.println();
                }
                return outerList;
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 判断Excel的版本,获取Workbook
     *
     * @param file
     * @return
     * @throws IOException
     */
    public static org.apache.poi.ss.usermodel.Workbook getWorkbok(File file) throws IOException {
        org.apache.poi.ss.usermodel.Workbook wb = null;
        FileInputStream in = new FileInputStream(file);
        if (file.getName().endsWith(EXCEL_XLS)) {     //Excel&nbsp;2003
            wb = new HSSFWorkbook(in);
        } else if (file.getName().endsWith(EXCEL_XLSX)) {    // Excel 2007/2010
            wb = new XSSFWorkbook(in);
        }
        return wb;
    }

    private static String getValue(Cell cell) {
        String value = null;
        switch (cell.getCellType()) {
            case NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    Date date = cell.getDateCellValue();
                    DateFormat formater = new SimpleDateFormat("yyyy-MM-dd");
                    value = formater.format(date);
                } else if (String.valueOf(cell.getNumericCellValue()).contains(".")) {
                    DecimalFormat df = new DecimalFormat("#");
                    value = df.format(cell.getNumericCellValue());
                } else {
//                    value = (cell + "").trim();
                    value = String.valueOf(cell.getNumericCellValue());
                }
                break;
            case STRING:
                value = cell.getStringCellValue();
                break;
            case FORMULA:
                break;
            case BLANK:
                value = "";
                break;
            case BOOLEAN:
                value = String.valueOf(cell.getBooleanCellValue());
                break;
            case ERROR:
                break;
            default:
                break;
        }

        return value;
    }

     /**
     * 不同类型对应不同的取值范围
     *
     * @param cell
     * @return
     */
    public static String getCellValue(Cell cell) {
        String value = "";
        switch (cell.getCellType()) {
            case STRING:
                value = cell.getRichStringCellValue().getString();
                break;
            case NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    value = cell.getDateCellValue().toString();
                } else {
                    value = String.valueOf(cell.getNumericCellValue());
                }
                break;
            case BOOLEAN:
                value = String.valueOf(cell.getBooleanCellValue());
                break;
            case FORMULA:
                value = cell.getCellFormula();
                break;
            case BLANK:
                break;
            default:
        }
        return value;
    }

}

上面两个Demo,第一个基本上摘自别人博客的,但是第二个,别人博客是试用jxl进行读取的,所以这边将读取的逻辑改成了新版的POI对Excel进行读取,新的读取主要是增加了getCellTypeEnum()来判断单元格数据类型,最后在根据枚举类型返回需要的结果,之前的方法是cell.getCellTypeEnum()我这边看了下代码是一个已经被废弃的,所以就使用getCellTypeEnum()来进行取代了.

运行结果如下