POI生成Excel工具类

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

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

import org.apache.poi.hpsf.SummaryInformation;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
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 com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;

public class ExcelUtil {
	public static String NO_DEFINE = "no_define";// 未定义的字段
	public static String DEFAULT_DATE_PATTERN = "yyyy年MM月dd日 HH:mm:ss";// 默认日期格式
	public static int DEFAULT_COLOUMN_WIDTH = 20;

	/**
	 * 导出Excel 97(.xls)格式
	 * 
	 * @param title-标题行
	 * @param list-要输出的表单
	 * @param datePattern-日期格式,null则用默认日期格式
	 * @param colWidth-列宽,默认至少17个字节
	 * @param out-输出流
	 */
	public static void exportExcel(String title, List<FormExcelObject> list, String datePattern, int colWidth,
			OutputStream out) {
		if (datePattern == null)
			datePattern = DEFAULT_DATE_PATTERN;
		// 声明一个工作薄
		HSSFWorkbook workbook = new HSSFWorkbook();
		workbook.createInformationProperties();
		workbook.getDocumentSummaryInformation().setCompany("********公司");
		SummaryInformation si = workbook.getSummaryInformation();
		si.setAuthor("LAY"); // 填加xls文件作者信息
		si.setApplicationName("**系统导出程序"); // 填加xls文件创建程序信息
		si.setComments("LAY is a programmer!"); // 填加xls文件作者信息
		si.setTitle(title + "数据"); // 填加xls文件标题信息
		si.setSubject(title + "数据导出Excel");// 填加文件主题信息
		si.setCreateDateTime(new Date());
		// 表头样式
		HSSFCellStyle titleStyle = workbook.createCellStyle();
		titleStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
		HSSFFont titleFont = workbook.createFont();
		titleFont.setFontHeightInPoints((short) 20);
		titleFont.setBoldweight((short) 700);
		titleStyle.setFont(titleFont);
		// 列头样式
		HSSFCellStyle headerStyle = workbook.createCellStyle();
		headerStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
		headerStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
		headerStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
		headerStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
		headerStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
		HSSFFont headerFont = workbook.createFont();
		headerFont.setFontHeightInPoints((short) 12);
		headerFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
		headerStyle.setFont(headerFont);
		// 单元格样式
		HSSFCellStyle cellStyle = workbook.createCellStyle();
		cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN);
		cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN);
		cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN);
		cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN);
		cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
		cellStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
		HSSFFont cellFont = workbook.createFont();
		cellFont.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
		cellStyle.setFont(cellFont);

		for (int j = 0; j < list.size(); j++) {
			FormExcelObject formExcelObject = list.get(j);
			Map<String, String> headMap = formExcelObject.getHeadMap();
			JSONArray jsonArray = formExcelObject.getJsonArray();
			String _title = formExcelObject.getTitle();

			int k = 1;
			// 生成一个(带标题)表格
			HSSFSheet sheet = workbook.createSheet(_title + "-" + k);
			// 设置列宽
			int minBytes = colWidth < DEFAULT_COLOUMN_WIDTH ? DEFAULT_COLOUMN_WIDTH : colWidth;// 至少字节数
			int[] arrColWidth = new int[headMap.size()];
			// 产生表格标题行,以及设置列宽
			String[] properties = new String[headMap.size()];
			String[] headers = new String[headMap.size()];
			int ii = 0;
			for (Iterator<String> iter = headMap.keySet().iterator(); iter.hasNext();) {
				String fieldName = iter.next();

				properties[ii] = fieldName;
				headers[ii] = fieldName;

				int bytes = fieldName.getBytes().length;
				arrColWidth[ii] = bytes < minBytes ? minBytes : bytes;
				sheet.setColumnWidth(ii, arrColWidth[ii] * 256);
				ii++;
			}
			// 遍历集合数据,产生数据行
			int rowIndex = 0;
			for (Object obj : jsonArray) {
				if (rowIndex == 65535 || rowIndex == 0) {
					if (rowIndex != 0) {
						sheet = workbook.createSheet(_title + "-" + (++k));
						for (int i = 0; i < headers.length; i++) {
							sheet.setColumnWidth(i, arrColWidth[i] * 256);
						}
					}

					HSSFRow titleRow = sheet.createRow(0);// 表头 rowIndex=0
					titleRow.createCell(0).setCellValue(_title);
					titleRow.getCell(0).setCellStyle(titleStyle);
					sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, headMap.size() - 1));

					HSSFRow headerRow = sheet.createRow(1); // 列头 rowIndex =1
					for (int i = 0; i < headers.length; i++) {
						headerRow.createCell(i).setCellValue(headMap.get(headers[i]));
						headerRow.getCell(i).setCellStyle(headerStyle);

					}
					rowIndex = 2;// 数据内容从 rowIndex=2开始
				}
				JSONObject jo = (JSONObject) JSONObject.toJSON(obj);
				HSSFRow dataRow = sheet.createRow(rowIndex);
				for (int i = 0; i < properties.length; i++) {
					HSSFCell newCell = dataRow.createCell(i);

					Object o = jo.get(properties[i]);
					String cellValue = "";
					if (o == null)
						cellValue = "";
					else if (o instanceof Date)
						cellValue = new SimpleDateFormat(datePattern).format(o);
					else
						cellValue = o.toString();

					newCell.setCellValue(cellValue);
					newCell.setCellStyle(cellStyle);
				}
				rowIndex++;
			}

		}

		try {
			workbook.write(out);
			workbook.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 通过向response中写入数据实现web下载
	 * 
	 * @param title-文件名
	 * @param formExcelObjectList-表单数据
	 * @param response-要写入数据的响应
	 */
	public static void downloadExcelFile(String title, List<FormExcelObject> formExcelObjectList,
			HttpServletResponse response) {
		try {
			ByteArrayOutputStream os = new ByteArrayOutputStream();
			ExcelUtil.exportExcel(title, formExcelObjectList, null, 0, os);
			byte[] content = os.toByteArray();
			InputStream is = new ByteArrayInputStream(content);
			// 设置response参数,可以打开下载页面
			response.reset();

			response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8");
			response.setHeader("Content-Disposition",
					"attachment;filename=" + new String((title + ".xls").getBytes(), "iso-8859-1"));
			response.setContentLength(content.length);
			ServletOutputStream outputStream = response.getOutputStream();
			BufferedInputStream bis = new BufferedInputStream(is);
			BufferedOutputStream bos = new BufferedOutputStream(outputStream);
			byte[] buff = new byte[8192];
			int bytesRead;
			while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {
				bos.write(buff, 0, bytesRead);
			}
			bis.close();
			bos.close();
			outputStream.flush();
			outputStream.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static class FormExcelObject {
		private String title;
		private Map<String, String> headMap;
		private JSONArray jsonArray;

		public String getTitle() {
			return title;
		}

		public void setTitle(String title) {
			this.title = title;
		}

		public Map<String, String> getHeadMap() {
			return headMap;
		}

		public void setHeadMap(Map<String, String> headMap) {
			this.headMap = headMap;
		}

		public JSONArray getJsonArray() {
			return jsonArray;
		}

		public void setJsonArray(JSONArray jsonArray) {
			this.jsonArray = jsonArray;
		}

	}

	public static void main(String[] args) throws IOException {
		System.out.println("正在生成数据....");
		int count = 100000;
		JSONArray ja = new JSONArray();
		for (int i = 0; i < 100000; i++) {
			Student s = new Student();
			s.setName("POI" + i);
			s.setAge(i);
			s.setBirthday(new Date());
			s.setHeight(i);
			s.setWeight(i);
			s.setSex(i / 2 == 0 ? false : true);
			ja.add(s);
		}
		String jsonString = "{"name":"姓名","age":"年龄","birthday":"生日","height":"身高","weight":"体重","sex":"性别"}";
		LinkedHashMap<String, String> headMap = JSON.parseObject(jsonString,
				new TypeReference<LinkedHashMap<String, String>>() {
				});
		String title = "测试";
		OutputStream outXlsx = new FileOutputStream("D://b.xls");
		System.out.println("正在导出xls....");
		Date d2 = new Date();
		FormExcelObject feo = new FormExcelObject();
		feo.setTitle("测试title");
		feo.setHeadMap(headMap);
		feo.setJsonArray(ja);
		List<FormExcelObject> list = new ArrayList<FormExcelObject>();
		list.add(feo);
		ExcelUtil.exportExcel(title, list, null, 0, outXlsx);
		System.out.println("共" + count + "条数据,执行耗时" + (new Date().getTime() - d2.getTime()) + "ms");
		outXlsx.close();
	}

	public static class Student {
		private String name;
		private int age;
		private Date birthday;
		private float height;
		private double weight;
		private boolean sex;

		public String getName() {
			return name;
		}

		public void setName(String name) {
			this.name = name;
		}

		public Integer getAge() {
			return age;
		}

		public Date getBirthday() {
			return birthday;
		}

		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}

		public float getHeight() {
			return height;
		}

		public void setHeight(float height) {
			this.height = height;
		}

		public double getWeight() {
			return weight;
		}

		public void setWeight(double weight) {
			this.weight = weight;
		}

		public boolean isSex() {
			return sex;
		}

		public void setSex(boolean sex) {
			this.sex = sex;
		}

		public void setAge(Integer age) {
			this.age = age;
		}
	}
}

maven项目需要在pom文件中加入以下

<dependency>
  <groupId>org.apache.poi</groupId>
  <artifactId>poi</artifactId>
  <version>3.13</version>
</dependency>

<dependency>
  <groupId>com.alibaba</groupId>
  <artifactId>fastjson</artifactId>
  <version>1.2.7</version>
</dependency>

非maven项目中加入jar

fastjson-1.2.7.jar

poi-3.13.jar

注:HttpServletResponse相关类为tomcat中带有的jar,此处不予列出

原文地址:https://www.cnblogs.com/sm21312/p/6479897.html