本地生成Excel文件(参考网上文章)

package com.test;

import java.util.Date;

public class Student {
    private int id;
    private String name;
    private int age;
    private Date birth;

    public Student() {
    }

    public Student(int id, String name, int age, Date birth) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.birth = birth;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

    public Date getBirth() {
        return birth;
    }

    public void setBirth(Date birth) {
        this.birth = birth;
    }

}

package com.test;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.io.FileUtils;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class StudentCreateSimpleExcelToDisk {
    /**
     * @功能：手工构建一个简单格式的Excel
     */
    private static List<Student> getStudent() throws Exception {
        List list = new ArrayList();
        SimpleDateFormat df = new SimpleDateFormat("yyyy-mm-dd");

        Student user1 = new Student(1, "张三", 16, df.parse("1997-03-12"));
        Student user2 = new Student(2, "李四", 17, df.parse("1996-08-12"));
        Student user3 = new Student(3, "王五", 26, df.parse("1985-11-12"));
        list.add(user1);
        list.add(user2);
        list.add(user3);

        return list;
    }

    public static void main(String[] args) throws Exception {

        // 第一步，创建一个webbook，对应一个Excel文件
        HSSFWorkbook wb = new HSSFWorkbook();
        // 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet
        HSSFSheet sheet = wb.createSheet("学生表一");
        // 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
        HSSFRow row = sheet.createRow((int) 0);
        // 第四步，创建单元格，并设置值表头 设置表头居中
        HSSFCellStyle style = wb.createCellStyle();
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式

        HSSFCell cell = row.createCell((short) 0);
        cell.setCellValue("学号");
        cell.setCellStyle(style);
        cell = row.createCell((short) 1);
        cell.setCellValue("姓名");
        cell.setCellStyle(style);
        cell = row.createCell((short) 2);
        cell.setCellValue("年龄");
        cell.setCellStyle(style);
        cell = row.createCell((short) 3);
        cell.setCellValue("生日");
        cell.setCellStyle(style);

        // 第五步，写入实体数据 实际应用中这些数据从数据库得到，
        List list = StudentCreateSimpleExcelToDisk.getStudent();

        for (int i = 0; i < list.size(); i++) {
            row = sheet.createRow((int) i + 1);
            Student stu = (Student) list.get(i);
            // 第四步，创建单元格，并设置值
            row.createCell((short) 0).setCellValue((double) stu.getId());
            row.createCell((short) 1).setCellValue(stu.getName());
            row.createCell((short) 2).setCellValue((double) stu.getAge());
            cell = row.createCell((short) 3);
            cell.setCellValue(new SimpleDateFormat("yyyy-mm-dd").format(stu.getBirth()));
        }
        // 第六步，将文件存到指定位置1
        try {
            OutputStream outputStream = new ByteArrayOutputStream();
            FileOutputStream fout = new FileOutputStream("E:/students.xls");
            wb.write(fout);
            fout.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        // 第六步，将文件存到指定位置2
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        wb.write(outputStream);
        FileUtils.writeByteArrayToFile(new File("E:/students1.xls"), outputStream.toByteArray());

    }
}