利用FileChannel完成文件的读、写、复制

落日映苍穹つ 2021-09-14 02:30 450阅读 0赞

内容：通过NIO中的FileChannel完成文件的读、写、复制。

**\[java\]**  [view plain][]   [copy][view plain]

1.  **public** **class** NioFileCopy \{  
2.      **private** RandomAccessFile aFile = **null**;  
3.      **private** FileChannel inChannel = **null**;  
4.      **private** **final** ByteBuffer buf = ByteBuffer.allocate(1024);  
5.        
6.      **public** **void** doWrite() **throws** IOException \{  
7.          aFile = **new** RandomAccessFile("C:/goods.txt", "rw");  
8.          inChannel = aFile.getChannel();  
9.          String newData = "New String to wirte to file... " + System.currentTimeMillis();  
10.         buf.clear();  
11.         buf.put(newData.getBytes());  
12.           
13.         buf.flip();  
14.           
15.         **while** (buf.hasRemaining())   
16.             inChannel.write(buf);  
17.           
18.         inChannel.close();  
19.         System.out.println("Write Over");  
20.     \}  
21.       
22.     **public** **void** doRead() **throws** IOException \{  
23.         aFile = **new** RandomAccessFile("C:/goods.txt", "rw");  
24.         inChannel = aFile.getChannel();  
25.           
26.         **int** bytesRead = inChannel.read(buf);  
27.         **while** (bytesRead != -1) \{  
28.             System.out.println("Read " + bytesRead);  
29.             buf.flip();  
30.             **while** (buf.hasRemaining())  
31.                 System.out.print((**char**) buf.get());  
32.               
33.             buf.clear();  
34.             bytesRead = inChannel.read(buf);  
35.         \}  
36.           
37.         aFile.close();  
38.     \}  
39.       
40.     **public** **void** doCopy() **throws** IOException \{  
41.         aFile = **new** RandomAccessFile("C:/goods.txt", "rw");  
42.         inChannel = aFile.getChannel();  
43.         RandomAccessFile bFile = **new** RandomAccessFile("C:/22.log", "rw");  
44.         FileChannel outChannel = bFile.getChannel();  
45.         inChannel.transferTo(0, inChannel.size(), outChannel);  
46.         System.out.println("Copy over");  
47.     \}  
48.       
49.     **public** **static** **void** main(String\[\] args) **throws** IOException \{  
50.         NioFileCopy tool = **new** NioFileCopy();  
51.         //tool.doWrite();  
52.         //tool.doRead();  
53.         tool.doCopy();  
54.     \}  
55. \}

[view plain]: http://blog.csdn.net/u011345136/article/details/45501559#