web开发中，一个系统的普通需求也包括导出excel，一般采用POI做统计报表导出excel。

导出excel工具类：

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

public class ExportExcel {

	private ExportExcel() {
		super();
	}

	public static void exportExcel(List<Object> list, Map<Integer, Long> map,
			String[] titles) throws IOException {
		// 创建Excel文档
		HSSFWorkbook hwb = new HSSFWorkbook();
		// sheet 对应一个工作页
		HSSFSheet sheet = hwb.createSheet("exportReport");
		int colNum = titles.length;
		// 创建第一行
		HSSFRow firstrow = sheet.createRow(0);
		HSSFCell[] firstcell = new HSSFCell[colNum];
		for (int col = 0; col < colNum; col++) {
			firstcell[col] = firstrow.createCell(col);
			firstcell[col].setCellValue(new HSSFRichTextString(titles[col]));
		}

		// 插入记录
		int rowNum = map.size();
		for (int i = 0; i < rowNum; i++) {
			// 从第二行开始
			HSSFRow row = sheet.createRow(i + 1);
			// 插入list中的字段
			for (int col = 0; col < colNum - 2; col++) {
				HSSFCell cell = row.createCell(col);
				cell.setCellValue(list.get(col).toString());
			}
			// 插入月份或日期
			row.createCell(colNum - 2).setCellValue(i + 1);
			// 插入总量
			row.createCell(colNum - 1).setCellValue(map.get(i + 1));
		}
		String fileName = titles[1].substring(0, 2);
		if (colNum == 4) {
			fileName += list.get(0) + "_" + list.get(1) + "年_年度报表";
		} else if (colNum == 5) {
			fileName += list.get(0) + "_" + list.get(1) + "年" + list.get(2)
					+ "月_月度报表";
		}
		// 创建文件输出流，准备输出电子表格
		OutputStream out = new FileOutputStream("../webapps/UsedMallMinaServer/files/"
				+ fileName + ".xls");
		hwb.write(out);
		out.close();
	}
}