我有一些代码从多播套接字读取数据,直到用户定义的结束时间。Thread.interrupt
如果线程通过调用(或您可以提出的任何其他用户启动的操作)中断,我也想停止读取数据。我不知道如何在线程中断时获得通知。现有代码如下:
// These are the constants I am given
final int mcastPort = ...;
final InetAddress mcastIP = ...;
final InetAddress ifaceIP = ...; // Null indicates all interfaces should be used
final Instant endTime = ...; // Time at which to stop processing
// Initialize a datagram
final byte[] buffer = new byte[1000];
final DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
// Process incoming datagram packets
try (final MulticastSocket socket = new MulticastSocket(port)) {
socket.joinGroup(mcastIP);
if (ifaceIP != null)
socket.setInterface(ifaceIP);
do {
final Duration soTimeout = Duration.between(Instant.now(), endTime);
socket.setSoTimeout(soTimeout);
socket.receive(packet);
// Process packet
...
} while (true);
} catch (final SocketTimeoutException e) {
// Normal condition... the recording time has ended
} catch (final ClosedByInterruptException e) {
// Uh-oh... this never happens
} ...
我看到有一个DatagramSocket.getChannel
返回 a 的方法DatagramChannel
,所以我自然假设该类型用于读取/写入底层套接字。这个假设是不正确的,这意味着MulticastSocket
没有实现InterruptibleChannel
. 因此,MulticastSocket.receive
从不抛出ClosedByInterruptException
.
我在网上搜索了示例,但无法弄清楚如何修改上述代码以使用 aDatagramChannel
而不是MulticastSocket
. 我需要帮助的问题是:
- 如何在 DatagramChannel 上设置 SO_TIMEOUT 参数?
- 如何将a 转换
InetAddress
为NetworkInterface
对象?
以下是我对如何将实现从 转换MulticastSocket
为DatagramChannel
以满足我的要求的最佳猜测:
// Initialize a buffer
final ByteBuffer buffer = ByteBuffer.allocate(1000);
try (final DatagramChannel mcastChannel = DatagramChannel.open()) {
mcastChannel.setOption(StandardSocketOptions.SO_REUSEADDR, true);
mcastChannel.connect(new InetSocketAddress(port));
mcastChannel.join(mcastIP);
if (ifaceIP != null)
// HELP: this option requires an InterfaceAddress object,
// but I only have access to an InetAddress object
mcastChannel.setOption(StandardSocketOptions.IP_MULTICAST_IF, ifaceIP);
do {
final Duration soTimeout = Duration.between(Instant.now(), endTime);
// HELP: SO_TIMEOUT is not a member of StandardSocketOptions
mcastChannel.setOption(SO_TIMEOUT, ???);
mcastChannel.receive(buffer);
// Process packet
...
} while (true);
} ...
这种方法甚至会奏效吗? DatagramChannel.receive
没有SocketTimeoutException
列为它能够抛出的异常之一。如果这可行,那么请让我知道我需要如何将第二个实现更改为与第一个实现等效,但能够ClosedByInterruptException
在客户端调用Thread.interrupt
. 如果没有,那么是否有人对我如何满足在预定义时间停止数据报接收的要求有任何其他想法,同时还提供一种通过用户交互停止执行的方法?