设置套接字操作的超时

When I create a socket:

当我创建一个套接字时：

Socket socket = new Socket(ipAddress, port);

It throws an exception, which is OK, because the IP address is not available. (The test variables where String ipAddress = "192.168.0.3" and int port = 300.)

它会引发异常，这是正常的，因为IP地址不可用。（测试变量，其中String ipAddress =“192.168.0.3”和int port = 300.）

The problem is: how do I set it to timeout for that socket?

问题是：如何将其设置为该套接字的超时？

When I create the socket, how do I reduce the time before I get a UnknownHostException and get the socket to timeout?

当我创建套接字时，如何在收到UnknownHostException并使套接字超时之前减少时间？

5 个解决方案

#1

135

Use the Socket() constructor, and connect(SocketAddress endpoint, int timeout) method instead.

使用Socket（）构造函数，然后连接（SocketAddress endpoint，int timeout）方法。

In your case it would look something like:

在你的情况下，它看起来像：

Socket socket = new Socket();
socket.connect(new InetSocketAddress(ipAddress, port), 1000);

Quoting from the documentation

引用文档

connect

连
public void connect(SocketAddress endpoint, int timeout) throws IOException
Connects this socket to the server with a specified timeout value. A timeout of zero is interpreted as an infinite timeout. The connection will then block until established or an error occurs.

使用指定的超时值将此套接字连接到服务器。超时为零被解释为无限超时。然后，连接将阻塞，直到建立或发生错误。

Parameters:

参数：

endpoint - the SocketAddress
timeout - the timeout value to be used in milliseconds.

endpoint - SocketAddress timeout - 要使用的超时值，以毫秒为单位。

Throws:

抛出：

IOException - if an error occurs during the connection
SocketTimeoutException - if timeout expires before connecting
IllegalBlockingModeException - if this socket has an associated channel, and the channel is in non-blocking mode
IllegalArgumentException - if endpoint is null or is a SocketAddress subclass not supported by this socket

IOException - 如果连接期间发生错误SocketTimeoutException - 如果超时在连接IllegalBlockingModeException之前到期 - 如果此套接字具有关联的通道，并且通道处于非阻塞模式IllegalArgumentException - 如果endpoint为null或者是此类不支持的SocketAddress子类插座

Since: 1.4

自：1.4

#2

You don't set a timeout for the socket, you set a timeout for the operations you perform on that socket.

您没有为套接字设置超时，您为在该套接字上执行的操作设置了超时。

For example socket.connect(otherAddress, timeout)

例如socket.connect（otherAddress，timeout）

Or socket.setSoTimeout(timeout) for setting a timeout on read() operations.

或者socket.setSoTimeout（timeout）用于在read（）操作上设置超时。

See: http://docs.oracle.com/javase/7/docs/api/java/net/Socket.html

请参阅：http：//docs.oracle.com/javase/7/docs/api/java/net/Socket.html

#3

You could use the following solution:

您可以使用以下解决方案：

SocketAddress sockaddr = new InetSocketAddress(ip, port);
// Create your socket
Socket socket = new Socket();
// Connect with 10 s timeout
socket.connect(sockaddr, 10000);

Hope it helps!

希望能帮助到你！

#4

You can't control the timeout due to UnknownHostException. These are DNS timings. You can only control the connect timeout given a valid host. None of the preceding answers addresses this point correctly.

由于UnknownHostException，您无法控制超时。这些是DNS计时。给定有效主机时，您只能控制连接超时。前面的答案都没有正确地解决这一问题。

But I find it hard to believe that you are really getting an UnknownHostException when you specify an IP address rather than a hostname.

但是，当您指定IP地址而不是主机名时，我发现很难相信您确实收到了UnknownHostException。

EDIT To control Java's DNS timeouts see this answer.

编辑要控制Java的DNS超时，请参阅此答案。

#5

Use the default constructor for Socket and then use the connect() method.

使用Socket的默认构造函数，然后使用connect（）方法。

#1

135