import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.MappedByteBuffer;

import java.nio.channels.FileChannel;

import java.nio.file.Files;

public class FileCopy {

    public static void fileCopyByByte(String inPah, String outPah)

            throws FileNotFoundException, IOException {

        byte[] byteArray = new byte[1024];

        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(

                inPah));

        BufferedOutputStream bos = new BufferedOutputStream(

                new FileOutputStream(outPah));

        int readCount = 0;

        while ((readCount = bis.read(byteArray)) != -1) {

            bos.write(byteArray, 0, readCount);

            bos.flush();

        }

        bis.close();

        bos.close();

    }

    public static void fileCopyByChar(String inPah, String outPah)

            throws FileNotFoundException, IOException {

        char[] charArray = new char[1024];

        BufferedReader reader = new BufferedReader(new FileReader(inPah));

        BufferedWriter writer = new BufferedWriter(new FileWriter(outPah));

        int readCount = 0;

        while ((readCount = reader.read(charArray)) != -1) {

            writer.write(charArray, 0, readCount);

            writer.flush();

        }

        reader.close();

        writer.close();

    }

    public static void fileCopyByFileChannel(String inPah,String outPah) throws FileNotFoundException,IOException{

        FileInputStream fis = new FileInputStream(inPah);

        FileOutputStream fos = new FileOutputStream(outPah);

        FileChannel fileChannel_from = fis.getChannel();

        FileChannel fileChannel_to = fos.getChannel();       

        ByteBuffer bytebuffer = ByteBuffer.allocate(1024);

        // Read data from file into ByteBuffer

        int bytesCount;

        while ((bytesCount = fileChannel_from.read(bytebuffer)) > 0) {

         //flip the buffer which set the limit to current position, and position to 0

         bytebuffer.flip();

         //write data from ByteBuffer to file

         fileChannel_to.write(bytebuffer);

         //for the next read

         bytebuffer.clear();

        }

        fileChannel_from.close();

        fileChannel_to.close();

    }

    public static void fileCopyByFileChannelMap(String inPah,String outPah) throws FileNotFoundException,IOException{

        FileInputStream fis = new FileInputStream(inPah);

        FileOutputStream fos = new FileOutputStream(outPah);

        FileChannel fileChannel_from = fis.getChannel();

        FileChannel fileChannel_to = fos.getChannel();       

        MappedByteBuffer bytebuffer = fileChannel_from.map(FileChannel.MapMode.READ_ONLY, 0, fileChannel_from.size());

        fileChannel_to.write(bytebuffer);

        bytebuffer.clear();

        fileChannel_from.close();

        fileChannel_to.close();

    }

    public static void main(String[] args) {

        try {

            String in = "E:/小说/左道旁门.txt";

            long begin = System.currentTimeMillis();

            fileCopyByByte(in, "e:/2");

            System.out.println(System.currentTimeMillis() - begin);

            begin = System.currentTimeMillis();

            fileCopyByFileChannel(in, "e:/3");

            System.out.println(System.currentTimeMillis() - begin);

            begin = System.currentTimeMillis();

            fileCopyByFileChannelMap(in, "e:/4");

            System.out.println(System.currentTimeMillis() - begin);

            begin = System.currentTimeMillis();

            Files.copy(new File(in).toPath(), new File("e:/5").toPath());

            System.out.println(System.currentTimeMillis() - begin);

        } catch (FileNotFoundException e) {

                e.printStackTrace();

        } catch (IOException e) {

                e.printStackTrace();

        }

    }

}