Apache POI 4.0.1版本读取普通Excel文件(兼容 xls 和 xlsx)(一)

基于最新的Apache POI 4.0.1版本来总结一下整个读取和写入Excel的过程。

代码编写前准备-》

添加POI 4.0.1 maven依赖：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.springbootedemo</groupId>
    <artifactId>springboot-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>springboot-demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
     
        <dependency>
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>1.11.3</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.41</version>
        </dependency>

        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.10</version>
        </dependency>

       
        <dependency>
            <groupId>commons-beanutils</groupId>
            <artifactId>commons-beanutils</artifactId>
            <version>1.8.3</version>
        </dependency>

 <!--poi -->
     <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.0.1</version>
        </dependency>
      <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>4.0.1</version>
        </dependency>

    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

example-01.xlsx 文件 ，excel数据准备：

上代码：

DataVo(封装数据VO类)

package com.springbootemaildemo.excel.b;

/**
 * 读取Excel时，封装读取的每一行的数据
 */
public class DataVo {
    /**
     * 姓名
     */
    private String name;

    /**
     * 年龄
     */
    private Integer age;


    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

}

ExcelReader（主要读取excel文件代码类）

package com.springbootemaildemo.excel.b;

import org.apache.commons.lang3.StringUtils;
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 org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;

/**
 * 读取Excel内容
 */
public class ExcelReader {
    private static final Logger logger = LoggerFactory.getLogger(ExcelReader.class);
    private static final String XLS = "xls";
    private static final String XLSX = "xlsx";

    /**
     * 根据文件后缀名类型获取对应的工作簿对象
     *
     * @param inputStream 读取文件的输入流
     * @param fileType    文件后缀名类型（xls或xlsx）
     * @return 包含文件数据的工作簿对象
     * @throws IOException
     */
    public static Workbook getWorkbook(InputStream inputStream, String fileType) throws IOException {
        Workbook workbook = null;
        if (fileType.equalsIgnoreCase(XLS)) {
            workbook = new HSSFWorkbook(inputStream);
        } else if (fileType.equalsIgnoreCase(XLSX)) {
            workbook = new XSSFWorkbook(inputStream);
        }
        return workbook;
    }

    /**
     * 读取Excel文件内容
     *
     * @param fileName 要读取的Excel文件所在路径
     * @return 读取结果列表，读取失败时返回null
     */
    public static List<DataVo> readExcel(String fileName) {
        Workbook workbook = null;
        FileInputStream inputStream = null;
        try {
            // 获取Excel后缀名
            String fileType = fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length());
            // 获取Excel文件
            File excelFile = new File(fileName);
            if (!excelFile.exists()) {
                logger.warn("指定的Excel文件不存在！");
                return null;
            }
            // 获取Excel工作簿
            inputStream = new FileInputStream(excelFile);
            workbook = getWorkbook(inputStream, fileType);

            // 读取excel中的数据
            List<DataVo> resultDataList = parseExcel(workbook);
            return resultDataList;
        } catch (Exception e) {
            logger.warn("解析Excel失败，文件名：" + fileName + " 错误信息：" + e.getMessage());
            return null;
        } finally {
            try {
                if (null != workbook) {
                    workbook.close();
                }
                if (null != inputStream) {
                    inputStream.close();
                }
            } catch (Exception e) {
                logger.warn("关闭数据流出错！错误信息：" + e.getMessage());
                return null;
            }
        }
    }

    /**
     * 解析Excel数据
     *
     * @param workbook Excel工作簿对象
     * @return 解析结果
     */
    private static List<DataVo> parseExcel(Workbook workbook) {
        List<DataVo> resultDataList = new ArrayList<>();
        // 解析sheet
        int numberOfSheets = workbook.getNumberOfSheets();
        for (int sheetNum = 0; sheetNum < numberOfSheets; sheetNum++) {
            Sheet sheet = workbook.getSheetAt(sheetNum);

            // 校验sheet是否合法
            if (sheet == null) {
                continue;
            }
            // 获取第一行数据
            int firstRowNum = sheet.getFirstRowNum();
            Row firstRow = sheet.getRow(firstRowNum);
            if (null == firstRow) {
                logger.warn("解析Excel失败，在第一行没有读取到任何数据！");
            }
            // 解析每一行的数据，构造数据对象
            int rowStart = firstRowNum + 1;
            int rowEnd = sheet.getPhysicalNumberOfRows();
            for (int rowNum = rowStart; rowNum < rowEnd; rowNum++) {
                Row row = sheet.getRow(rowNum);
                if (null == row) {
                    continue;
                }
                DataVo resultData = convertRowToData(row);
                if (null == resultData) {
                    logger.warn("第 " + row.getRowNum() + "行数据不合法，已忽略！");
                    continue;
                }
                resultDataList.add(resultData);
            }
        }
        return resultDataList;
    }

    /**
     * 将单元格内容转换为字符串
     *
     * @param cell
     * @return
     */
    private static String convertCellValueToString(Cell cell) {
        if (cell == null) {
            return null;
        }
        String returnValue = null;
        switch (cell.getCellType()) {
            case NUMERIC:   //数字
                Double doubleValue = cell.getNumericCellValue();
                // 格式化科学计数法，取一位整数
                DecimalFormat df = new DecimalFormat("0");
                returnValue = df.format(doubleValue);
                break;
            case STRING:    //字符串
                returnValue = cell.getStringCellValue();
                break;
            case BOOLEAN:   //布尔
                Boolean booleanValue = cell.getBooleanCellValue();
                returnValue = booleanValue.toString();
                break;
            case BLANK:     // 空值
                break;
            case FORMULA:   // 公式
                returnValue = cell.getCellFormula();
                break;
            case ERROR:     // 故障
                break;
            default:
                break;
        }
        return returnValue;
    }

    /**
     * 提取每一行中需要的数据，构造成为一个结果数据对象
     * <p>
     * 当该行中有单元格的数据为空或不合法时，忽略该行的数据
     *
     * @param row 行数据
     * @return 解析后的行数据对象，行数据错误时返回null
     */
    private static DataVo convertRowToData(Row row) {
        DataVo resultData = new DataVo();
        Cell cell;
        int cellNum = 0;
        // 获取姓名
        cell = row.getCell(cellNum++);
        String name = convertCellValueToString(cell);
        resultData.setName(name);
        // 获取年龄
        cell = row.getCell(cellNum++);
        String ageStr = convertCellValueToString(cell);
        if (StringUtils.isEmpty(ageStr)) {
            // 年龄为空
            resultData.setAge(null);
        } else {
            resultData.setAge(Integer.parseInt(ageStr));
        }
        return resultData;
    }
}

MyTest(测试类）

package com.springbootemaildemo.excel.b;

import org.apache.commons.collections4.CollectionUtils;

import java.util.List;

public class MyTest {
    public static void main(String[] args) {
        // 设定Excel文件所在路径
        String excelFileName = "E:\\files\\example-01.xlsx";
        // 读取Excel文件内容
        List<DataVo> readResult = ExcelReader.readExcel(excelFileName);
        //TODO 可以写相应的业务
        if (CollectionUtils.isNotEmpty(readResult)) {
            readResult.stream().forEach(dataVo -> {
                System.out.println(dataVo.getName() + "-" + dataVo.getAge());
            });
        }
    }

}

结果：