求一个输入输出流的实例

[lrstom]

求一个输入输出流的实例...最好有详细的介绍为好....

[hzc543806053]

InputStream in = new InputStream() ;//输入流
OutputStream out = new OutputStream() ; //输出流

更详细推荐参考 think in java

[kouyiSC]

读取文件：
	/**
	 * 读取xls文件到set
	 * 
	 * @throws Exception
	 */
	public static Set<String> readXlsfile(File filePath) {
		
		Set<String> set = new HashSet<String>();
		try {
			// long l = System.currentTimeMillis();
			InputStream is = new FileInputStream(filePath);
			Workbook rwb = Workbook.getWorkbook(is);
			Sheet[] sheets = rwb.getSheets();// 获得当前Excel表共有几个sheet
			int p = sheets.length;
			// System.out.println("此表共有几个sheet------->" + p);
			for (int w = 0; w < p; w++) {
				// 将每个sheet中的内容全部读取出来
				Sheet rs = rwb.getSheet(w);
				int rows = rs.getRows();
				for (int d = 1; d < rows; d++) {
					// 行循环,Excel的行列是从（0，0）开始的
					Cell b00 = rs.getCell(0, d);
					String strb = b00.getContents();
					set.add(strb);
				}
			}
			// System.out.println("mapping执行之间：" + (System.currentTimeMillis() - l) + "毫秒");
			 System.out.println("长度" + set.size());
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
		return set;
	}

写入文件:
	/**
	 * 将数据写入xls文件中,并下载到本地
	 */
	public static void writeXlsFile(List<String> set, File file, String fileName, HttpServletResponse 
			response) throws Exception {

		if (Utils.isNull(set))
			return;
		OutputStream ot = new FileOutputStream(file);
		// 创建excel文件
		WritableWorkbook wwb = Workbook.createWorkbook(ot);
		// 设置表头字体
		WritableFont wtitlefont = new WritableFont(WritableFont.TIMES, 11,
				WritableFont.BOLD, false, UnderlineStyle.NO_UNDERLINE,
				Colour.BLACK);
		WritableCellFormat titleformat = new WritableCellFormat(wtitlefont);
		// WritableSheet sheet = wwb.createSheet("测试大数据量", 0);

		String[] titles = new String[] { "电话号码" };
		int setIndex = 0;
		int cellNumber = 60000;
		int setSize = set.size();
		int setNum = setSize / 60000;
		if (setSize % 60000 != 0)
			setNum = setNum + 1;
		for (int num = 0; num < setNum; num++) {
			String sheetName = "收信人" + String.valueOf(num + 1);
			WritableSheet sheet = wwb.createSheet(sheetName, 0);
			// 设置excel表头
			int row = 0;
			int column = 0;
			for (String title : titles) {
				Label label0 = new Label(column, row, title, titleformat);
				sheet.addCell(label0);
				column++;
			}
			// 写入正文
			if (num == (setNum - 1)) {
				cellNumber = setSize - (num * 60000);
			}
			SetSheetCell(sheet, set, cellNumber, setIndex);
			setIndex = setIndex + cellNumber;
		}
		// 提交写入数据并关闭
		wwb.write();
		wwb.close();
		ot.close();

		// 下载文件
		try {
			fileName = "new_noblack_" + fileName;
			download(file, fileName, response);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			// e.printStackTrace();
			System.out.println("下载文件异常" + e.getMessage());
		}
	}

[bcw52]

楼上示例很详细.