java Netty 之 文件传输

java Netty 之 文件传输

 

 

/** 
  * 文件传输接收端，没有处理文件发送结束关闭流的情景 
  */ 
public class FileServerHandler extends SimpleChannelHandler { 
	private File file = new File("F:/2.txt"); 
	private FileOutputStream fos; 
	public FileServerHandler() { 
		try { 
			if (!file.exists()) { 
				file.createNewFile();
			} else { 
				file.delete(); file.createNewFile(); 
			} 
			
			fos = new FileOutputStream(file); 
		} catch (IOException e) { 
			e.printStackTrace(); 
		} 
	} 
	
	@Override public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception { 
		ChannelBuffer buffer = (ChannelBuffer) e.getMessage(); 
		int length = buffer.readableBytes(); 
		buffer.readBytes(fos, length); 
		fos.flush(); 
		buffer.clear(); 
	}
}

 

/** 
  * 文件发送客户端，通过字节流来发送文件，仅实现文件传输部分， 
  * 没有对文件传输结束进行处理 
  * 应该发送文件发送结束标识，供接受端关闭流。 
  */ 
public class FileClientHandler extends SimpleChannelHandler { 

	// 每次处理的字节数 
	private int readLength = 8; 
	
	@Override public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception { 
		// 发送文件 sendFile(e.getChannel()); 
	} 
	
	private void sendFile(Channel channel) throws IOException { 
		File file = new File("E:/1.txt"); 
		FileInputStream fis = new FileInputStream(file); 
		int count = 0; 
		for (;;) { 
			BufferedInputStream bis = new BufferedInputStream(fis); 
			byte[] bytes = new byte[readLength]; 
			int readNum = bis.read(bytes, 0, readLength); 
			if (readNum == -1) { 
				return; 
			} 
			sendToServer(bytes, channel, readNum); 
			System.out.println("Send count: " + ++count); 
		} 
	} 
	
	private void sendToServer(byte[] bytes, Channel channel, int length) throws IOException {
		ChannelBuffer buffer = ChannelBuffers.copiedBuffer(bytes, 0, length); 
		channel.write(buffer); 
	}
}

 

 

      这只是一个简单的文件传输的例子，可以做为样例借鉴。对于大文件传输的情景，本样例并不支持，会出现内存溢出的情景。