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import java.io.IOException; 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;

import org.junit.Test;

@Test public void test2() throws IOException{ long start = System.currentTimeMillis();

	FileChannel inChannel = FileChannel.open(Paths.get("1.mp4"), StandardOpenOption.READ);
	FileChannel outChannel = FileChannel.open(Paths.get("2.mp4"), StandardOpenOption.WRITE, StandardOpenOption.READ, StandardOpenOption.CREATE);
	
	//内存映射文件
	MappedByteBuffer inMappedBuf = inChannel.map(MapMode.READ_ONLY, 0, inChannel.size());
	MappedByteBuffer outMappedBuf = outChannel.map(MapMode.READ_WRITE, 0, inChannel.size());
	
	//直接对缓冲区进行数据的读写操作
	byte[] dst = new byte[inMappedBuf.limit()];
	inMappedBuf.get(dst);
	outMappedBuf.put(dst);
	
	inChannel.close();
	outChannel.close();
	
	long end = System.currentTimeMillis();
	System.out.println("耗费时间为：" + (end - start));
}