Java生成excel导出文件

package com.mi.entity;

import java.util.Date;

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

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

}

package com.mi.util;

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

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;

import com.mi.entity.Student;

public class CreateSimpleExcelToDisk {

    /**
     * 手工创建一个包含student的list
     * @return
     * @throws Exception
     */
    private static List<Student> getStudent() throws Exception {
        List<Student> list = new ArrayList<>();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd");
        Student user1 = new Student(1, "张三", 16, sdf.parse("1997-03-12"));
        Student user2 = new Student(2, "李四", 17, sdf.parse("1996-08-12"));
        Student user3 = new Student(3, "王五", 26, sdf.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文件,对应一个excel文件
        HSSFWorkbook wb = new HSSFWorkbook();
        //第二部,在excel中添加一个sheet工作簿,参数为该工作簿名字,不写为默认;
        HSSFSheet sheet = wb.createSheet("学生表1");
        //第三部,做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);
        //第四部,创建单元格表头 设置表头居中
        HSSFCellStyle style = wb.createCellStyle();
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);//创建一个居中格式
        
        //创建具体盛放数据的单元格,可以考虑把cell抽成共通对象去使用
        HSSFCell cell = row.createCell((int) 0);
        cell.setCellValue("学号");
        cell = row.createCell((int) 1);
        cell.setCellValue("姓名");
        cell = row.createCell((int) 2);
        cell.setCellValue("年龄");
        cell = row.createCell((int) 3);
        cell.setCellValue("生日");
        
        //第五部,写入实体数据 实际应用中这些数据应该是从数据库中得到
        List<Student> list = CreateSimpleExcelToDisk.getStudent();
        for(int i=0;i<list.size();i++){
            //每次新建一行然后在新行中插入list中的数据对象,有点繁琐,也许有更好的封装方法,留待后看
            row = sheet.createRow((int)i+1);
            row.createCell((int)0).setCellValue(list.get(i).getId());
            row.createCell((int)1).setCellValue(list.get(i).getName());
            row.createCell((int)2).setCellValue(list.get(i).getAge());
            row.createCell((int)3).setCellValue(new SimpleDateFormat("yyyy-mm-dd").format(list.get(i).getBirth()));
            
        }
        
        //第六部,将文件保存到指定位置
        FileOutputStream fout = new FileOutputStream("D:/student.xls");
        wb.write(fout);
        fout.close();
    }
}