普通io與nio檔案複制效率對比（nio分直接緩沖區和非直接緩沖區）

測試檔案是一個壓縮包 

測試時間硬體不同 結果不同 但是總的排名應該是： 直接緩沖區 > 非直接緩沖區 > 普通io

普通io測試 代碼如下：耗時5144ms

long start = System.currentTimeMillis();

        FileInputStream fis = null;
        FileOutputStream fos = null;

        try {
            fis = new FileInputStream("F:\\00 GIT.zip");
            fos = new FileOutputStream("F:\\10101GIT.zip");

            byte bys[] = new byte[1024];

            int len = 0;
            //資料讀
            while ((len = fis.read(bys)) != -1) {
                //資料寫
                fos.write(bys, 0, len);
            }
            fos.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        long end = System.currentTimeMillis();
        System.out.println("耗費時間為：" + (end - start));//耗費時間為：5144      

非直接緩沖區測試：5091ms

long start = System.currentTimeMillis();

        FileInputStream fis = null;
        FileOutputStream fos = null;
        //1.擷取通道
        FileChannel inChannel = null;
        FileChannel outChannel = null;
        try {
            fis = new FileInputStream("F:\\00 GIT.zip");
            fos = new FileOutputStream("F:\\999GIT.zip");

            inChannel = fis.getChannel();
            outChannel = fos.getChannel();

            //2.配置設定指定大小的緩沖區
            ByteBuffer buf = ByteBuffer.allocate(1024);

            //3.将通道中的資料存入緩沖區中
            while (inChannel.read(buf) != -1) {
                buf.flip(); //切換讀取資料的模式
                //4.将緩沖區中的資料寫入通道中
                outChannel.write(buf);
                buf.clear(); //清空緩沖區
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (outChannel != null) {
                try {
                    outChannel.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (inChannel != null) {
                try {
                    inChannel.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        long end = System.currentTimeMillis();
        System.out.println("耗費時間為：" + (end - start));//耗費時間為：5091      

long start = System.currentTimeMillis();

        FileChannel inChannel = FileChannel.open(Paths.get("F:\\00 GIT.zip"), StandardOpenOption.READ);
        FileChannel outChannel = FileChannel.open(Paths.get("F:\\11.zip"), StandardOpenOption.WRITE, StandardOpenOption.READ, StandardOpenOption.CREATE);

        //記憶體映射檔案
        MappedByteBuffer inMappedBuf = inChannel.map(MapMode.READ_ONLY, 0, inChannel.size());
        MappedByteBuffer outMappedBuf = outChannel.map(MapMode.READ_WRITE, 0, inChannel.size());

        //直接對緩沖區進行資料的讀寫操作
        byte[] dst = new byte[inMappedBuf.limit()];
      
        inMappedBuf.get(dst);
        outMappedBuf.put(dst);

        inChannel.close();
        outChannel.close();

        long end = System.currentTimeMillis();
        System.out.println("耗費時間為：" + (end - start));//耗費時間為：1454