实体List转为excel

		<dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.17</version>
        </dependency>

package com.mabo.excel;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.CellStyle;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.lang.reflect.Field;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

public class CreateTest<T> {
    

    public static<T> File create(Class<T> aClass, List<T> list, String fileName) throws IOException {
    
        // 创建一个webbook，对应一个Excel文件
        HSSFWorkbook wb = new HSSFWorkbook();
        // 在webbook中添加一个sheet,对应Excel文件中的sheet
        HSSFSheet sheet = wb.createSheet("sheet1");
        // 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(0);
        // 添加标题行
        HSSFCell cell = null;
        Field[] fields = aClass.getDeclaredFields();
        for (int i = 0; i < fields.length; i++) {
    
            // 获取行内对应单元格
            cell = row.createCell(i);
            // 单元格赋值
            cell.setCellValue(fields[i].getName());
        }
        // 写入实体数据，实际应用中这些数据从数据库得到,list中字符串的顺序必须和数组strArray中的顺序一致
        int i = 0;
        for (int j = 0; j < list.size(); j++) {
    
            T t = list.get(i);
            i++;
            row = sheet.createRow(i );
            // 添加数据行
            //数据转为Json
            String json= JSON.toJSONString(t);//关键
            JSONObject parse = (JSONObject) JSONObject.parse(json);
            for (int z = 0; z < fields.length; z++) {
    
                Field field=fields[z];
                cell = row.createCell(z);
                // 获取行内对应单元格
                String name = field.getName();
                Object o = parse.get(name);
                // 单元格赋值

                if (o instanceof Long){
    
                    long o1 = (long) o;
                    Date date = new Date();
                    date.setTime(o1);
                    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    cell.setCellValue(simpleDateFormat.format(date));
                }
                else if (o instanceof String){
    
                    cell.setCellValue((String) o);
                }
                else if (o instanceof Double){
    
                    cell.setCellValue((double) o);
                }
                else if (o instanceof Boolean){
    
                    cell.setCellValue((boolean) o);
                }
            }
        }
// // 第六步，将文件存到指定位置
        FileOutputStream fout = new FileOutputStream(fileName);
        try {
    
            wb.write(fout);
            fout.close();
        } catch (Exception e) {
    
            e.printStackTrace();
        }
        finally {
    
            fout.close();
        }

        return new File(fileName);
    }

}