POI 多線程多sheet導出數據

import org.apache.commons.beanutils.PropertyUtilsBean;
import org.apache.commons.lang.StringUtils;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;

import java.beans.PropertyDescriptor;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/***
 * POI 多線程多sheet導出數據
 */
public class ThreadExcelUtils {

	/**
	 * 定義每個 sheet 最多數量
	 */
	public static final Integer EXCEL_MAX_CNT = 50000;

	private Workbook wb;
	private String fileName;
	private String filePath;
	private String[] hearders;
	private String[] fields;

	public Workbook getWb() {
		return wb;
	}

	public String getFileName() {
		return fileName;
	}

	public String getFilePath() {
		return filePath;
	}

	public String[] getHearders() {
		return hearders;
	}

	public String[] getFields() {
		return fields;
	}

	/**
	 * @param fileName
	 *            文件名稱
	 * @param filePath
	 *            文件路徑
	 * @param hearders
	 *            文件頭
	 * @param fields
	 *            字段屬性
	 */
	public ThreadExcelUtils(String fileName, String filePath,
			String[] hearders, String[] fields) {
		this.wb = new HSSFWorkbook();
		this.fileName = fileName;
		this.filePath = filePath;
		this.hearders = hearders;
		this.fields = fields;
	}

	public static void main(String[] args) throws Exception {

		List<Map<String, Object>> lists = new ArrayList<Map<String, Object>>();

		// 造數據
		for (int i = 0; i < 10000; i++) {
			Map<String, Object> map = new HashMap<String, Object>();
			map.put("name1", "張三" + i);
			map.put("name2", "李四" + i);
			map.put("name3", "王五" + i);
			lists.add(map);
		}

		String[] header = { "姓名1", "姓名2", "姓名3" };
		String[] fileNames = { "name1", "name2", "name3" };

		String filePath = "D:\\excelFile";
		String filename = "測試表 " + getDate(new Date()) + ".xls";
		ThreadExcelUtils utils = new ThreadExcelUtils(filename, filePath,
				header, fileNames);
		System.out.println("開始執行導出.......");
		long start = System.currentTimeMillis();
		utils.exportExcelToFilePath(lists);
		long end = System.currentTimeMillis();
		System.out.println("耗時：" + (end - start) / 1000 + "秒");

	}

	/**
	 * @param list
	 *            數據
	 */
	public void exportExcelToFilePath(List<Map<String, Object>> list)
			throws Exception {
		int excelSize = EXCEL_MAX_CNT; // 每個Excel文件條數
		int totalCount = list.size(); // 查詢結果總條數
		int pageCount = 0;// 總sheet頁個數
		int numPage = totalCount % excelSize; // 是否整頁數
		if (numPage > 0)
			pageCount = totalCount / excelSize + 1;
		else
			pageCount = totalCount / excelSize;
		// 創建線程池 多sheet多線程寫入 線程數 爲sheet頁的 1/4
		Integer threadNumber = pageCount / 4;
		if (threadNumber == 0)
			threadNumber = 1;
		ExecutorService threadPool = Executors.newFixedThreadPool(threadNumber);
		// 創建柵欄 等待任務完成
		CountDownLatch countDownLatch = new CountDownLatch(pageCount);
		// 循環遍歷投遞任務
		for (int i = 1; i <= pageCount; i++) {
			ThraedExcel thraedExcel = new ThraedExcel(list, i, pageCount,
					numPage, this);
			thraedExcel.setCountDownLatch(countDownLatch);
			threadPool.execute(thraedExcel);
		}
		countDownLatch.await();
		Workbook wb = getWb();
		File file = new File(filePath);
		FileOutputStream fout = new FileOutputStream(new File(file, fileName));
		try {
			wb.write(fout);
		} catch (IOException e) {
			e.printStackTrace();
		}
		// System.out.println("文件寫入完成");
		// 立即銷燬線程池
		threadPool.shutdownNow();
	}

	private static String getDate(Date date) {
		SimpleDateFormat simpleDateFormat = new SimpleDateFormat(
				"yyyyMMddHHmmss");
		String format = simpleDateFormat.format(date);
		return format;
	}

	/**
	 * JavaBean轉Map
	 * 
	 * @param obj
	 * @return
	 */
	public static Map<String, Object> beanToMap(Object obj) {
		Map<String, Object> params = new HashMap<String, Object>(0);
		try {
			PropertyUtilsBean propertyUtilsBean = new PropertyUtilsBean();
			PropertyDescriptor[] descriptors = propertyUtilsBean
					.getPropertyDescriptors(obj);
			int length = descriptors.length;
			for (int i = 0; i < length; i++) {
				String name = descriptors[i].getName();
				if (!StringUtils.equals(name, "class")) {
					params.put(name, propertyUtilsBean.getNestedProperty(obj,
							name));
				}
			}
		} catch (Exception e) {
			System.err.println("bean 轉Map出錯");
			e.printStackTrace();
		}
		return params;
	}

	/***
	 * 線程寫入sheet
	 */
	private static class ThraedExcel implements Runnable {

		private List<Map<String, Object>> list;// 數據
		private Integer sheetNumber;// 當前sheet頁
		private Integer totalSheetCount;// 總數據
		private int numPage; // 是否整頁數
		private Integer excelSize;
		private ThreadExcelUtils threadExcelUtils;
		// 柵欄對象
		private CountDownLatch countDownLatch;

		/**
		 * @param list
		 *            總數據
		 * @param sheetNumber
		 *            當前sheet頁
		 * @param totalSheetCount
		 *            總sheet頁
		 * @param numPage
		 *            是否整數
		 */
		public ThraedExcel(List<Map<String, Object>> list, Integer sheetNumber,
				Integer totalSheetCount, Integer numPage,
				ThreadExcelUtils threadExcelUtils) {
			this.list = list;// 總數據
			this.sheetNumber = sheetNumber;// 當前sheet頁
			this.totalSheetCount = totalSheetCount;// 總sheet頁
			this.numPage = numPage;// 是否整除
			this.excelSize = ThreadExcelUtils.EXCEL_MAX_CNT;// 沒個sheet最大數量
			this.threadExcelUtils = threadExcelUtils;// 當前線程對象
		}

		public void setCountDownLatch(CountDownLatch countDownLatch) {
			this.countDownLatch = countDownLatch;
		}

		@Override
		public void run() {
			List<Map<String, Object>> sheetList = null;
			if (totalSheetCount > 1) {
				if (numPage == 0) {
					sheetList = list.subList((sheetNumber - 1) * excelSize,
							excelSize * sheetNumber);
				} else {
					if (sheetNumber == totalSheetCount) {
						sheetList = list.subList((sheetNumber - 1) * excelSize,
								list.size());
					} else {
						sheetList = list.subList((sheetNumber - 1) * excelSize,
								excelSize * (sheetNumber));
					}
				}
			} else
				sheetList = list;
			// 開始寫入數據
			createWorkBook(sheetList);
			if (this.countDownLatch != null)
				this.countDownLatch.countDown();
		}

		/***
		 * 寫出數據
		 */
		private void createWorkBook(List<Map<String, Object>> sheetList) {
			Sheet sheet = null;
			Row row = null;
			synchronized (ThreadExcelUtils.class) {
				String fileName = threadExcelUtils.getFileName();
				Workbook wb = threadExcelUtils.getWb();
				sheet = wb.createSheet(fileName + "_" + this.sheetNumber);
				row = sheet.createRow(0);
			}
			String[] header = threadExcelUtils.getHearders();
			String[] fields = threadExcelUtils.getFields();
			// 設置標題
			for (int i = 0; i < header.length; i++) {
				row.createCell(i).setCellValue(header[i]);
			}
			// 開始寫入數據
			if (sheetList != null && sheetList.size() > 0) {
				int dataLength = sheetList.size();
				for (int i = 0; i < dataLength; i++) {
					if (i == 3 || i == 8 || i == 15) {
						sheet.setColumnWidth(i, 20 * 256);
					} else {
						sheet.setColumnWidth(i, 15 * 256);
					}

					Row row1 = sheet.createRow(i + 1);
					Object obj = sheetList.get(i);
					Map<String, Object> map = (obj instanceof Map) ? (Map<String, Object>) obj
							: beanToMap(obj);
					int length = fields.length;
					for (int j = 0; j < length; j++) {
						String key = fields[j];
						Object value = map.get(key);
						if (value != null) {
							// 不曉得 此處爲啥有線程安全問題
							synchronized (ThreadExcelUtils.class) {
								if (value instanceof Date) {
									SimpleDateFormat sdf = new SimpleDateFormat(
											"yyyy-MM-dd");
									String format = sdf.format(value);
									row1.createCell(j).setCellValue(format);
								} else {
									try {
										row1.createCell(j).setCellValue(
												value.toString());
									} catch (Exception e) {
										e.printStackTrace();
									}
								}
							}
						}
					}
				}
			}
		}
	}
}