使用非直接缓冲区和直接缓冲区复制同一个文件，看一下时间差别

1、创建非直接缓冲区测试类

package com.cppdy.nio;import java.io.FileInputStream;import java.io.FileOutputStream;import java.nio.ByteBuffer;import java.nio.channels.FileChannel;//使用非直接缓冲区和直接缓冲区复制同一个文件，看一下时间差别public class NIOBufferDemo3 {    public static void main(String[] args) throws Exception {        long start = System.currentTimeMillis();        FileInputStream fis = new FileInputStream("F:\\cppdy\\1.mp4");        FileOutputStream fos = new FileOutputStream("F:\\cppdy\\2.mp4");        FileChannel inChannel = fis.getChannel();        FileChannel outChannel = fos.getChannel();        ByteBuffer buf = ByteBuffer.allocate(1024);        while (inChannel.read(buf) != -1) {            buf.flip();            outChannel.write(buf);            buf.clear();        }        outChannel.close();        inChannel.close();        fos.close();        fis.close();        long end = System.currentTimeMillis();        System.out.println("使用非直接缓冲区复制完毕mp4，耗时：" + (end - start));    }}

2、创建直接缓冲区测试类

package com.cppdy.nio;import java.nio.MappedByteBuffer;import java.nio.channels.FileChannel;import java.nio.channels.FileChannel.MapMode;import java.nio.file.Paths;import java.nio.file.StandardOpenOption;//使用非直接缓冲区和直接缓冲区复制同一个文件，看一下时间差别public class NIOBufferDemo4 {    public static void main(String[] args) throws Exception {        long start = System.currentTimeMillis();        // 直接缓冲区        FileChannel inChannel = FileChannel.open(Paths.get("F:\\cppdy\\1.mp4"), StandardOpenOption.READ);        FileChannel outChannel = FileChannel.open(Paths.get("F:\\cppdy\\2.mp4"), StandardOpenOption.READ,                StandardOpenOption.WRITE, StandardOpenOption.CREATE);        // 缓冲区        MappedByteBuffer inMap = inChannel.map(MapMode.READ_ONLY, 0, inChannel.size());        MappedByteBuffer outMap = outChannel.map(MapMode.READ_WRITE, 0, inChannel.size());        // 直接对缓冲区进行数据读写操作        byte[] bytes = new byte[inMap.limit()];        inMap.get(bytes);        outMap.put(bytes);        outMap.clear();        outChannel.close();        inChannel.close();        long end = System.currentTimeMillis();        System.out.println("使用直接缓冲区复制完毕mp4，耗时：" + (end - start));    }}