java文件IO操作。

 

public static void main(String[] args) {
		String filename = "F:/zhangming_test/test.txt";
		String filename1 = "F:/zhangming_test/test1.txt";
		String docfileName = "F:/猪猪猫xp系统.rar";
		// String filename = "F:/zhangming_test/test_doc.doc";
		// readFile(filename);
		// copyFileBychar(filename);
		copyFileByByte(docfileName);
		System.out.println("ddd");

	}

	/**
	 * 该方法只支持读取字符文件并复制文件. 按行读取的  文件锁未考虑
	 * 
	 * @param filename
	 */
	public static void copyFileBychar(String filename) {

		FileReader fileReader = null;
		BufferedWriter bufferedWriter = null;
		try {
			bufferedWriter = new BufferedWriter(new PrintWriter(new File(
					"F:/zhangming_test/test2.txt")));
			fileReader = new FileReader(new File(filename));
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
		BufferedReader bufferedReader = new BufferedReader(fileReader);
		String linecontent = null;
		try {
			// 調用readLine方法會移動流的指針
			while ((linecontent = bufferedReader.readLine()) != null) {
				System.out.println(linecontent);
				bufferedWriter.write(linecontent);
			}
			bufferedWriter.flush();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				bufferedReader.close();
				bufferedWriter.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	/**
	 * 每次读取一定数量byte的文件流. 文件锁未考虑
	 * @param inputFileName
	 */
	public static void copyFileByByte(String inputFileName) {
		InputStream inputStream = null;
		OutputStream outputStream = null;
		
		try {
			inputStream = new FileInputStream(new File(inputFileName));
			// ==方法一(一次性把文件的所有内容都添加读取到byte中)==
			// inputStream.read(bs);
			// outputStream = new FileOutputStream(new File(
			// "F:/zhangming_test/test6.doc"));
			// outputStream.write(bs);

			// ==方法二==
			outputStream = new FileOutputStream(new File(
					"F:/猪猪猫xp系统1.rar"));
			byte[] tmpBytes = new byte[1024];
			while (inputStream.read(tmpBytes) != -1) {
				outputStream.write(tmpBytes, 0, tmpBytes.length);
			}
			outputStream.flush();
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
		} finally {
			try {
				outputStream.close();
				inputStream.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

public static void copyFileWithNio(String srcFile, String destFile) {

		try {
			FileChannel srcChannel = new FileInputStream(new File(srcFile))
					.getChannel();
			FileChannel destChannel = new FileOutputStream(new File(destFile))
					.getChannel();
		

			try {
				destChannel.transferFrom(srcChannel, 0, srcChannel.size());
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				try {
					srcChannel.close();
					destChannel.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}

		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
	}    //最简单，使用代码最少。

以后开发的时候要用直接拿过来修修改改就OK了。当然可以考虑使用nio读取.