io流效率的比较

public class IOTest {

	public static void main(String[] args) {
		IOTest io = new IOTest();
		try {
			long startTime = System.currentTimeMillis();
			io.readWrite("d:/file/aa.txt", "d:/file/bb.txt");
			long endTime = System.currentTimeMillis();
			System.out.println("Time taken for reading and writing using default behaviour : "
							+ (endTime - startTime) + " milli seconds");
			long startTime1 = System.currentTimeMillis();
			io.readWriteBuffer("d:/file/aa.txt", "d:/file/bb.txt");
			long endTime1 = System.currentTimeMillis();
			System.out.println("Time taken for reading and writing using buffered streams : "
							+ (endTime1 - startTime1) + " milli seconds");
			long startTime2 = System.currentTimeMillis();
			io.readWriteArray("d:/file/aa.txt", "d:/file/bb.txt");
			long endTime2 = System.currentTimeMillis();
			System.out.println("Time taken for reading and writing using custom buffering : "
							+ (endTime2 - startTime2) + " milli seconds");
			long startTime3 = System.currentTimeMillis();
			io.readWriteCustom("d:/file/aa.txt", "d:/file/bb.txt");
			long endTime3 = System.currentTimeMillis();
			System.out.println("Time taken for reading and writing using custom buffering : "
							+ (endTime3 - startTime3) + " milli seconds");
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public static void readWrite(String fileFrom, String fileTo)
			throws IOException {
		InputStream in = null;
		OutputStream out = null;
		try {
			in = new FileInputStream(fileFrom);
			out = new FileOutputStream(fileTo);
			while (true) {
				int bytedata = in.read();
				if (bytedata == -1)
					break;
				out.write(bytedata);
			}
		}
		finally {
			if (in != null)
				in.close();
			if (out != null)
				out.close();
		}
	}

	public static void readWriteBuffer(String fileFrom, String fileTo)
			throws IOException {
		InputStream inBuffer = null;
		OutputStream outBuffer = null;
		try {
			InputStream in = new FileInputStream(fileFrom);
			inBuffer = new BufferedInputStream(in);
			OutputStream out = new FileOutputStream(fileTo);
			outBuffer = new BufferedOutputStream(out);
			while (true) {
				int bytedata = inBuffer.read();
				if (bytedata == -1)
					break;
				out.write(bytedata);
			}
		}
		finally {
			if (inBuffer != null)
				inBuffer.close();
			if (outBuffer != null)
				outBuffer.close();
		}
	}

	public static void readWriteArray(String fileFrom, String fileTo)
			throws IOException {
		InputStream in = null;
		OutputStream out = null;
		try {
			in = new FileInputStream(fileFrom);
			out = new FileOutputStream(fileTo);
			int availableLength = in.available();
			byte[] totalBytes = new byte[availableLength];
			int bytedata = in.read(totalBytes);
			out.write(totalBytes);
		}
		finally {
			if (in != null)
				in.close();
			if (out != null)
				out.close();
		}
	}

	public static void readWriteCustom(String from, String to)
			throws IOException {
		InputStream in = new FileInputStream(from);
		OutputStream out = new FileOutputStream(to);
		try {
			byte[] bytes = new byte[128 * 1024];
			int len;
			while ((len = in.read(bytes)) > 0) {
				out.write(bytes, 0, len);
			}
		} finally {
			if (in != null)
				in.close();
			if (out != null)
				out.close();
		}
	}
}

经测试最后一种方式，速度最快！不知道是否有比他更快的方式！？