Excel报表导出工具类

package com.yuezhu.utils;

/**
 * Created by Administrator on 2017/9/2.
 */

import java.io.FileOutputStream;
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;

public class ExportUtil {
        /**
         * @功能：Excel报表导出
         * @param name //报表名称
         * @param arr  //报表各列名称存放的String[]数组
         * @param list<.Dto> //报表每条数据对应的Dto集合
         */
        public static void  exportExcel(String name, String[] arr,List list){
            // 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(name);
            // 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);
            for(int i=0;i<arr.length;i++){
                cell = row.createCell((short) i);
                cell.setCellValue(arr[i]);
                cell.setCellStyle(style);
            }
            // 第五步，写入封装数据
            for(int i=0;i<list.size();i++){
                row = sheet.createRow((int) i + 1);
                java.lang.reflect.Field[] fields = list.get(i).getClass().getDeclaredFields();//获取i对象的所有字段
                for(int j=0;j<fields.length;j++) {
                    fields[j].setAccessible(true);
                    Object value = null;
                    try {
                        value = fields[j].get(list.get(i));//获取字段值
                    } catch (IllegalArgumentException e) {
                        e.printStackTrace();
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    }
                    System.out.println(value);
                    cell = row.createCell((short) j);
                    // 定义单元格为字符串类型，这个字符串类型也可在创建单元格里面设置。
                    cell.setCellType(HSSFCell.CELL_TYPE_STRING);
                    cell.setCellValue(String.valueOf(value));
                    cell.setCellStyle(style);
                }
            }
            // 第六步，将文件存到指定位置
            try
            {
                FileOutputStream fout = new FileOutputStream("E:/expport.xls");
                wb.write(fout);
                fout.close();
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
    }
/*//以下为测试
        private static List<Student> getStudent() throws Exception
        {
            List list = new ArrayList();
            Student user1 = new Student(1, "张三",16,"1997-05-06");
            Student user2 = new Student(2, "李四",17,"1996-08-12");
            Student user3 = new Student(3, "王五",26,"1985-11-12");
            list.add(user1);
            list.add(user2);
            list.add(user3);
            return list;
        }
        public static void main(String[] args) throws Exception
        {
            String name = "报表测试";
            String arr[] = {"学号","姓名","年龄","生日"};
            List list = new ArrayList();
            Student user1 = new Student(1,"张三",16,"1997-05-06");
            Student user2 = new Student(2, "李四", 17,"1996-08-12");
            Student user3 = new Student(3, "王五", 26,"1985-11-12");
            list.add(user1);
            list.add(user2);
            list.add(user3);
            //
            ExportUtil.exportExcel(name,arr,list);
        }*/
    }