package com.iailab.common.utils;

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.VerticalAlignment;
import org.apache.poi.ss.util.CellRangeAddress;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Excel 导出通用工具类
 *
 * @author PanZhibao
 * @date 2021年06月29日 9:06
 */
public class ExcelUtil {

    /**
     * 导出PointValueExcel
     *
     * @param sheetTitle
     * @param title
     * @param list
     * @param response
     * @return
     */
    public static byte[] exportPointValue(String sheetTitle, String[] title, List<Object> list, HttpServletResponse response) {

        HSSFWorkbook wb = new HSSFWorkbook();//创建excel表
        HSSFSheet sheet = wb.createSheet(sheetTitle);
        sheet.setDefaultColumnWidth(20);//设置默认行宽

        //表头样式（加粗，水平居中，垂直居中）
        HSSFCellStyle cellStyle = wb.createCellStyle();
        cellStyle.setAlignment(HorizontalAlignment.CENTER);//水平居中
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中

        HSSFFont fontStyle = wb.createFont();

        cellStyle.setFont(fontStyle);

        //标题样式（加粗，垂直居中）
        HSSFCellStyle cellStyle2 = wb.createCellStyle();
        cellStyle2.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
        cellStyle2.setFont(fontStyle);

        //字段样式（垂直居中）
        HSSFCellStyle cellStyle3 = wb.createCellStyle();
        cellStyle3.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中

        //数字样式
        HSSFCellStyle cellStyle4 = wb.createCellStyle();
        HSSFDataFormat df = wb.createDataFormat(); // 此处设置数据格式
        cellStyle4.setVerticalAlignment(VerticalAlignment.CENTER);//垂直居中
        cellStyle4.setDataFormat(df.getFormat("#,##0.000000"));//设置数值类型格式为保留两位小数

        //创建表头
        HSSFRow row = sheet.createRow(0);
        //row.setHeightInPoints(20);//行高

        HSSFCell cell = row.createCell(0);
        cell.setCellValue(sheetTitle);
        cell.setCellStyle(cellStyle);

        sheet.addMergedRegion(new CellRangeAddress(0,0,0,(title.length-1)));

        //创建标题
        HSSFRow rowTitle = sheet.createRow(1);
        //rowTitle.setHeightInPoints(20);

        HSSFCell hc;
        for (int i = 0; i < title.length; i++) {
            hc = rowTitle.createCell(i);
            hc.setCellValue(title[i]);
            hc.setCellStyle(cellStyle2);
        }

        byte result[] = null;

        try {
            //创建表格数据
            Field[] fields;
            int i = 2;
            for (Object obj : list) {
                fields = obj.getClass().getDeclaredFields();

                HSSFRow rowBody = sheet.createRow(i);
                //rowBody.setHeightInPoints(20);

                int j = 0;
                for (Field f : fields) {

                    f.setAccessible(true);

                    Object va = f.get(obj);
                    if (null == va) {
                        va = "";
                    }

                    hc = rowBody.createCell(j);

                    if (j == 0) {
                        hc.setCellValue(Double.parseDouble(va.toString()));
                        hc.setCellStyle(cellStyle4);
                    } else {
                        hc.setCellValue(va.toString());
                        hc.setCellStyle(cellStyle3);
                    }


                    j++;
                }

                i++;
            }

            //设置Http响应头告诉浏览器下载这个附件
            response.setHeader("Content-Disposition", "attachment;Filename=" + System.currentTimeMillis() + ".xls");
            OutputStream outputStream = response.getOutputStream();
            wb.write(outputStream);
            outputStream.close();
            return wb.getBytes();
        } catch (Exception ex) {
            Logger.getLogger(ExcelUtil.class.getName()).log(Level.SEVERE, null, ex);
            return result;
        } finally{
            try {
                wb.close();
            } catch (IOException ex) {
                Logger.getLogger(ExcelUtil.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}