高速复制文件方式

    public static synchronized void copyFile(final InputStream sourcefile, final OutputStream targetFile) {
        try {
            long statTime = System.currentTimeMillis();
//            FileInputStream fileInputStream = new FileInputStream(sourcefile);
            int buffSize = 10 * 1024;//10
            BufferedInputStream inbuff = new BufferedInputStream(sourcefile, buffSize);
//            FileOutputStream fileOutputStream = new FileOutputStream(targetFile);// 新建文件输出流并对它进行缓冲
            BufferedOutputStream outbuff = new BufferedOutputStream(targetFile, buffSize);
            //int fileVolume = (int) (dirSize / (1024 * 1024));
            FileChannel fileChannelOutput = null;//fileOutputStream.getChannel();
            ReadableByteChannel readableByteChannel = Channels.newChannel(inbuff);
            FileChannel fileChannelInput = null;//fileInputStream.getChannel();
            WritableByteChannel writableByteChannel = Channels.newChannel(outbuff);
            //fileChannelInput.transferTo(0, fileChannelInput.size(), fileChannelOutput);
            long transferSize = 0;
            DecimalFormat decimalFormat = new DecimalFormat(".00");//构造方法的字符格式这里如果小数不足2位,会以0补足.
            /*ByteBuffer buffer = ByteBuffer.allocate(buffSize);
            while (readableByteChannel.read(buffer) != -1) {
                buffer.flip();
                transferSize += writableByteChannel.write(buffer);
                buffer.clear();
            }*/
            byte[] bt = new byte[buffSize];
            int c;
            while ((c = inbuff.read(bt)) > 0) {
                transferSize += c;
                outbuff.write(bt, 0, c);
            }
            outbuff.flush();
            inbuff.close();
            outbuff.close();
            targetFile.flush();
            targetFile.close();
            sourcefile.close();
            writableByteChannel.close();
            readableByteChannel.close();
            /*fileOutputStream.close();
            fileInputStream.close();
            fileChannelOutput.close();
            fileChannelInput.close();*/
            float time = (System.currentTimeMillis() - statTime) / 1000f;
            float speed = transferSize / (time * 1024 * 1024f);
            Log.e(WiFiDirectActivity.TAG, "speed:" + decimalFormat.format(speed) + "MB/s, time:" + decimalFormat.format(time) + "s");
        } catch (FileNotFoundException e) {
            Log.e(WiFiDirectActivity.TAG, "CopyPasteUtil copyFile error:" + e.getMessage());
        } catch (IOException e) {
            Log.e(WiFiDirectActivity.TAG, "CopyPasteUtil copyFile error:" + e.getMessage());
        }
    }