自從jdk1.4以後就引入了NIO檔案通道的概念，並且是由io的FileinputStream和FileoutputStream獲取

以下程式碼傳入引數

File Copyfile 複製的檔案
File newfile  新檔案

1.傳統IO複製

	public static void traditionCopy(File Copyfile, File newfile) throws Exception {
		FileInputStream fis = null;
		FileOutputStream fos = null;
		byte[] buffer = new byte[2097152];
		try {
			fis = new FileInputStream(Copyfile);
			fos = new FileOutputStream(newfile);
			int read = 0;
			long startTime = System.currentTimeMillis();
			while ((read = fis.read(buffer)) != -1) {
				fos.write(buffer, 0, read);
			}
			long EndTime = System.currentTimeMillis();
			System.out.print("traditionCopy用了毫秒數：");
			System.out.println(EndTime - startTime);
			fos.flush();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (fos != null) {
				fos.close();
			}
			if (fis != null) {
				fis.close();
			}
		}
	}
 

2.NIO複製

	public static void nioCopy(File Copyfile, File newfile) throws Exception {
		FileInputStream fis = null;
		FileOutputStream fos = null;
		FileChannel inFiC = null;
		FileChannel outFoC = null;
		int length = 2097152;
		try {
			fis = new FileInputStream(Copyfile);
			fos = new FileOutputStream(newfile);
			inFiC = fis.getChannel();
			outFoC = fos.getChannel();
			long startTime = System.currentTimeMillis();
			while (inFiC.position() != inFiC.size()) {
				if ((inFiC.size() - inFiC.position()) < length) {
					length = (int) (inFiC.size() - inFiC.position());// 讀取剩下的
				}
				inFiC.transferTo(inFiC.position(), length, outFoC);
				inFiC.position(inFiC.position() + length);
			}
			long EndTime = System.currentTimeMillis();
			System.out.print("nioCopy,用了毫秒總數：");
			System.out.println(EndTime - startTime);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (outFoC != null) {
				outFoC.close();
			}
			if (inFiC != null) {
				inFiC.close();
			}
			if (fos != null) {
				fos.close();
			}
			if (fis != null) {
				fis.close();
			}
		}
	}
 

3.NIO檔案記憶體映像複製

	public static void nioMappedCopy(File Copyfile, File newfile) throws Exception {
		FileInputStream fis = null;
		FileOutputStream fos = null;
		FileChannel inFiC = null;
		FileChannel outFoC = null;
		int length = 2097152;
		try {
			fis = new FileInputStream(Copyfile);
			fos = new FileOutputStream(newfile);
			inFiC = fis.getChannel();
			outFoC = fos.getChannel();
			long startTime = System.currentTimeMillis();
			while (inFiC.position() != inFiC.size()) {
				if ((inFiC.size() - inFiC.position()) < length) {
					length = (int) (inFiC.size() - inFiC.position());
				}
				MappedByteBuffer inbuffer = inFiC.map(MapMode.READ_ONLY, inFiC.position(), length);
				outFoC.write(inbuffer);
				inFiC.position(inFiC.position() + length);
			}
			long EndTime = System.currentTimeMillis();
			System.out.print("nioMappedCopy用了毫秒數：");
			System.out.println(EndTime - startTime);
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (outFoC != null) {
				outFoC.close();
			}
			if (inFiC != null) {
				inFiC.close();
			}
			if (fos != null) {
				fos.close();
			}
			if (fis != null) {
				fis.close();
			}
		}
	}
 

	public static void main(String[] args) throws Exception {
		File Copyfile = new File("D:\\test\\eclipse-mars.7z");
		File newfilePath = new File("D:\\test\\2\\");
		if (!newfilePath.exists()) {
			newfilePath.mkdirs();
		}
		File traditionNewFile = new File(newfilePath + "/" + "traditionCopy.7z");
		traditionCopy(Copyfile, traditionNewFile);// traditionCopy用了毫秒數：644


		File nioNewFile = new File(newfilePath + "/" + "nioCopy.7z");
		nioCopy(Copyfile, nioNewFile);// nioCopy,複製檔案用了毫秒總數：283


		File nioMappedNewFile = new File(newfilePath + "/" + "nioMappedCopy.7z");
		nioMappedCopy(Copyfile, nioMappedNewFile);//nioMappedCopy用了毫秒數：266


	}

PS:終於寫完了。希望以後的自己看到這程式碼要說一句：這破程式碼誰寫的。哈哈。