导出Excl工具类

import java.io.IOException;
import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.util.CellRangeAddress;

import lombok.extern.slf4j.Slf4j;

/***
* 导出EXCEL工具类
*/
@Slf4j
public class GenerateExcelUtils {
    /***
     * 工作簿
     */
    private static HSSFWorkbook workbook;

    /***
     * sheet
     */
    private static HSSFSheet sheet;
    /***
     * 标题行开始位置
     */
    private static final int TITLE_START_POSITION = 0;

    /***
     * 时间行开始位置
     */
    private static final int DATEHEAD_START_POSITION = 1;

    /***
     * 表头行开始位置
     */
    private static final int HEAD_START_POSITION = 3;
    /***
     * 统计金额行
     */
    private static final int TOTAL_PAYMENT_POSITION = 2;

    /***
     * 文本行开始位置
     */
    private static final int CONTENT_START_POSITION = 4;

    /**
     * @author: WANG BO
     * @param dataList
     *        对象集合
     * @param titleMap
     *        表头信息（对象属性名称->要显示的标题值)[按顺序添加]
     * @param sheetName
     *        sheet名称和表头值
     * @param filePath
     *         文件路径
     *@param totalPayMent
     *        总金额
     */
    public static HSSFWorkbook excelExport(List<?> dataList, Map<String, String> titleMap, String sheetName, BigDecimal totalPayMent) {
        // 初始化workbook

        // 写入处理结果
        try {
            initHSSFWorkbook(sheetName);
            // 标题行
            createTitleRow(titleMap, sheetName);
            // 时间行
            createDateHeadRow(titleMap);
            // 表头行
            createHeadRow(titleMap);
            //统计行
            createCountRow(totalPayMent,titleMap);
            // 文本行
            createContentRow(dataList, titleMap);
            //设置自动伸缩
            //autoSizeColumn(titleMap.size());
            //OutputStream out = new FileOutputStream(filePath);
            //workbook.write(out);
           // out.close();

        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return workbook;
    }
    
    /**
     * @Title: excelExport
     * @Description: 导出Excel的方法
     * @author:  
     * @date: 
     * @param dataList
     *            对象集合
     * @param fileName
     *            文件名称
     * @param sheetName
     *            sheet名称和表头值
     * @param titleMap
     *            表头信息（对象属性名称->要显示的标题值)[按顺序添加]
     * @param totalPayMent
     *            总金额
     * @throws Exception
     */
   public static void excelExport(HttpServletResponse response, List<?> dataList, String fileName, String sheetName, Map<String, String> titleMap, BigDecimal totalPayMent) throws Exception {
       // 初始化workbook
       initHSSFWorkbook(sheetName);
       // 标题行
       createTitleRow(titleMap, sheetName);
       // 时间行
       createDateHeadRow(titleMap);
       // 表头行
       createHeadRow(titleMap);
       // 统计行
       createCountRow(totalPayMent,titleMap);
       // 文本行
       createContentRow(dataList, titleMap);
       // 设置自动伸缩
       autoSizeColumn(titleMap.size());
       // 写入处理结果
        response.setHeader("Content-disposition",
                "attachment;filename=" + new String(fileName.getBytes("gbk"), "iso8859-1") + ".xls");
           response.flushBuffer();
           ServletOutputStream outStream = response.getOutputStream();
           try {
            workbook.write(outStream);
        } catch (Exception e) {
            log.error("导出Excel出错！详情：[{}]", e.toString());
            throw new IOException(e);
        } finally {
            outStream.close();
        }
   }

    /***
     *
     * @param sheetName
     *        sheetName
     */
    private static void initHSSFWorkbook(String sheetName) {
        workbook = new HSSFWorkbook();
        sheet = workbook.createSheet(sheetName);
    }

    /**
     * 生成标题（第零行创建）
     * @param titleMap 对象属性名称->表头显示名称
     * @param sheetName sheet名称
     */
    private static void createTitleRow(Map<String, String> titleMap, String sheetName) {
        CellRangeAddress titleRange = new CellRangeAddress(0, 0, 0, titleMap.size() - 1);
        sheet.addMergedRegion(titleRange);
        HSSFRow titleRow = sheet.createRow(TITLE_START_POSITION);
        HSSFCell titleCell = titleRow.createCell(0);
        titleCell.setCellValue(sheetName);
    }

    /**
     * 创建时间行（第一行创建）
     * @param titleMap 对象属性名称->表头显示名称
     */
    private static void createDateHeadRow(Map<String, String> titleMap) {
        CellRangeAddress dateRange = new CellRangeAddress(1, 1, 0, titleMap.size() - 1);
        sheet.addMergedRegion(dateRange);
        HSSFRow dateRow = sheet.createRow(DATEHEAD_START_POSITION);
        HSSFCell dateCell = dateRow.createCell(0);
        dateCell.setCellValue(new SimpleDateFormat("yyyy年MM月dd日").format(new Date()));
    }

    /**
     * 创建表头行（第三行创建）
     * @param titleMap 对象属性名称->表头显示名称
     */
    private static void createHeadRow(Map<String, String> titleMap) {
        // 第3行创建
        HSSFRow headRow = sheet.createRow(HEAD_START_POSITION);
        int i = 0;
        for (String entry : titleMap.keySet()) {
            HSSFCell headCell = headRow.createCell(i);
            headCell.setCellValue(titleMap.get(entry));
            i++;
        }
    }
    /**
     * 创建统计行（第二行创建）
     * @param totalPayment 统计金额
     */
    private static void createCountRow(BigDecimal totalPayment,Map<String, String> titleMap) {
        // 第2行创建
        CellRangeAddress dateRange = new CellRangeAddress(2, 2, 0, titleMap.size() - 1);
        sheet.addMergedRegion(dateRange);
        HSSFRow headRow = sheet.createRow(TOTAL_PAYMENT_POSITION);
       // int i = 0;
       // for (String entry : titleMap.keySet()) {
            HSSFCell headCell = headRow.createCell(0);
            headCell.setCellValue("支付金额总计：￥"+totalPayment);
            //i++;
       // }
    }

    /**
     *
     * @param dataList 对象数据集合
     * @param titleMap 表头信息
     */
    private static void createContentRow(List<?> dataList, Map<String, String> titleMap) {
        try {
            int i=0;
            for (Object obj : dataList) {
                HSSFRow textRow = sheet.createRow(CONTENT_START_POSITION + i);
                int j = 0;
                for (String entry : titleMap.keySet()) {
                    String method = "get" + entry.substring(0, 1).toUpperCase() + entry.substring(1);
                    Method m = obj.getClass().getMethod(method, null);
                    String value="";
                    if(m.invoke(obj, null) != null){
                        value =   m.invoke(obj, null).toString();
                    }
                    HSSFCell textcell = textRow.createCell(j);
                    textcell.setCellValue(value);
                    j++;
                }
                i++;
            }

        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
    /**
     * 自动伸缩列
     * @param size 列数
     */
    private static void autoSizeColumn(Integer size) {
        for (int j = 0; j < size; j++) {
            sheet.autoSizeColumn(j);
        }
    }
}