java使用poi读写Excel

package com.demo.excel;

import com.demo.pojo.Student;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
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.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List;

import static javax.xml.bind.JAXBIntrospector.getValue;

/**
 * Created by xfma on 2017/1/19.
 */
public class ReadExcel {

    final static String excelFileName = "F:/Test.xls";

    public static void main(String[] args) {
        try {
            createExcel(createStudent());
            List<Student> list = readExcel(excelFileName);
            for (int i = 0; i < list.size(); i++) {
                System.out.println(list.get(i).getName() + "\t" + list.get(i).getAge() + "\t" + list.get(i).getSchool() + "\t" + list.get(i).getAddress());
            }
        } catch (Exception e) {
            e.getStackTrace();
        }

    }

    /**
     * 读Excel
     *
     * @param excelFileName 文件名
     * @return
     * @throws Exception
     */
    public static List<Student> readExcel(String excelFileName) throws Exception {

        boolean isExcel2003 = true;
        if (!excelFileName.endsWith("xls")) {
            isExcel2003 = false;
        }
        File file = new File(excelFileName);
        FileInputStream fis = new FileInputStream(file);
        Workbook workbook = null;
        /*excel2003和2007不是用同一个对象读取的*/
        if (isExcel2003) {
            workbook = new HSSFWorkbook(fis);
        } else {
            workbook = new XSSFWorkbook(fis);
        }

        Sheet sheet = workbook.getSheetAt(0);//得到第0个Sheet
        sheet.getLastRowNum();
        List<Student> list = new ArrayList<Student>();
        for (int r = 0; r < sheet.getLastRowNum(); r++) {
            Row row = sheet.getRow(r + 1);//越过标题，从第二行读
            if (row != null) {
                Student student = new Student();
                Cell name = row.getCell(0);
                Cell age = row.getCell(1);
                Cell address = row.getCell(2);
                Cell school = row.getCell(3);
                student.setName(getValue(name).toString());
                float f = Float.parseFloat(getValue(age).toString());
                student.setAge((int) f);
                student.setAddress(getValue(address).toString());
                student.setSchool(getValue(school).toString());
                list.add(student);
            }
        }
        return list;
    }

    /**
     * 生成Excel
     *
     * @param list 对象集合
     * @throws Exception
     */
    public static void createExcel(List<Student> list) throws Exception {
        //1.创建一个HSSFWorkbook对象，每个HSSFWorkbook对应一个新的Excel文件
        HSSFWorkbook workbook = new HSSFWorkbook();
        //2.在HSSFWorkbook中添加一个sheet，对应Excel中的一个sheet表
        HSSFSheet sheet = workbook.createSheet("学生信息表");
        String[] cells = new String[]{"姓名", "年龄", "地址", "学校"};//表头
        int rowSize = list.size() + 1;//从第二条开始读，去掉标题
        for (int r = 0; r < rowSize; r++) {
            HSSFRow row = sheet.createRow(r);
            for (int c = 0; c < cells.length; c++) {

                HSSFCell cell = row.createCell(c);
                if (r == 0) {
                    cell.setCellValue(cells[c]);//创建表头
                } else {
                      /*往表内写数据*/
                    int index = r - 1;//从第一条数据往里面写
                    switch (c) {
                        case 0:
                            cell.setCellValue(list.get(index).getName());
                            continue;
                        case 1:
                            cell.setCellValue(list.get(index).getAge());
                            continue;
                        case 2:
                            cell.setCellValue(list.get(index).getAddress());
                            continue;
                        case 3:
                            cell.setCellValue(list.get(index).getSchool());
                            continue;
                    }
                }

            }
        }
        FileOutputStream fileOut = new FileOutputStream(excelFileName);
        workbook.write(fileOut);
        fileOut.flush();
        fileOut.close();
    }

    /**
     * 创建示例
     *
     * @return
     */
    public static List<Student> createStudent() {
        List<Student> list = new ArrayList<Student>();
        Student s1 = new Student("小黑", 18, "上海浦东", "复旦大学");
        Student s2 = new Student("小白", 19, "上海普陀", "同济大学");
        Student s3 = new Student("小玉", 22, "上海黄埔", "上海交通大学");
        Student s4 = new Student("小红", 20, "上海静安", "上海财经大学");
        list.add(s1);
        list.add(s2);
        list.add(s3);
        list.add(s4);
        return list;
    }
}

pojo：

package com.demo.pojo;

import java.io.Serializable;

/**
 * Created by xfma on 2017/1/19.
 */
public class Student implements Serializable{
    private String name;
    private Integer age;
    private String address;
    private String school;

    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;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getSchool() {
        return school;
    }

    public void setSchool(String school) {
        this.school = school;
    }

    public Student(String name, Integer age, String address, String school) {
        this.name = name;
        this.age = age;
        this.address = address;
        this.school = school;
    }

    public Student() {
    }
}

pom.xml：

<!-- POI -->
    <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi</artifactId>
      <version>3.15</version>
    </dependency>
    <!-- poi-ooxml -->
    <dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi-ooxml</artifactId>
      <version>3.15</version>
    </dependency>