DatagramChannel使用

最新推荐文章于 2021-12-08 10:44:43 发布

JoesonChan

最新推荐文章于 2021-12-08 10:44:43 发布

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分类专栏： Java NIO Java 文章标签： Java nio DatagramChannel UDP

本文链接：https://blog.csdn.net/chenxuegui1234/article/details/17839781

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DatagramChannel是nio中处理UDP的类,可以使用2种方式:

DatagramChannel.receive(ByteBuffer dst)和DatagramChannel.send(ByteBuffer src, SocketAddress target)

调用connect()之后,使用read和write.

方式一

send和receive示例

/**
 * @author cxg
 *
 */
public class DatagramChannelSender {
	
	public static void main(String[] args) {
		try {
			send();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	private static void send() throws IOException{
		DatagramChannel channel =DatagramChannel.open();
		ByteBuffer buffer =ByteBuffer.wrap("下雨的夜晚很安静".getBytes("utf-8"));
		channel.send(buffer, new InetSocketAddress("localhost",10022));
		
		channel.close();
	}
	
}

/**
 * @author cxg
 *
 */
public class DatagramChannelReveiver {
	
	public static void main(String[] args) {
		try {
			receive();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	private static void receive() throws IOException{
		DatagramChannel channel =DatagramChannel.open();
		channel.socket().bind(new InetSocketAddress(10022));
		
		ByteBuffer buffer =ByteBuffer.allocate(60);
		while(channel.receive(buffer)==null){ 
			try {
				Thread.sleep(1000);
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
		}
		
		buffer.flip();
		String recStr =Charset.forName("utf-8").newDecoder().decode(buffer).toString();
		System.out.println(recStr);
		
		channel.close();
		
	}
	
}

方式2

connect()说明

1.只起到,限制数据包的接收和发送来源

2.不会阻塞

3.使用read和write的必要条件,否则抛出"NotYetConnectedException "

其他注意

DatagramChannel不能注册SelectionKey.OP_CONNECT

数据包的最大容量是65507字节