做网络开发的想必对setSoTimeout这个方法很熟悉,知道是设置的超时事件。但是很多人都认为这个是设置链路的超时时间,但是查看相关文档的此方法的说明:

HttpConnectionParams:
Sets the default socket timeout (SO_TIMEOUT) in milliseconds which is the
timeoutfor waiting for data.
A timeout value of zero is interpreted as an infinite timeout. This value is
used when no socket timeout is setin the method parameters.
Socket:
Enable/disable SO_TIMEOUT with the specified timeout, in milliseconds. With
this option set to a non-zero timeout,
a read() call on the InputStream associated with this Socket will block for
only this amount oftime. If the timeout expires,
a java.net.SocketTimeoutException is raised, though the Socket is still valid.
The option must be enabled prior to entering the blocking operation to have
effect.
The timeout must be > 0. A timeout of zero is interpreted as an infinite
timeout.
DatagramSocket:
Enable/disable SO_TIMEOUT with the specified timeout, in milliseconds. With
this option set to a non-zero timeout,
a call to receive() for this DatagramSocket will block for only this amount of
time. If the timeout expires, a java.net.SocketTimeoutException is raised,
though the DatagramSocket is still valid. The option must be enabled prior to
entering the blocking operation to have effect.
The timeout must be > 0. A timeout of zero is interpreted as an infinite
timeout.
看文档的详细说明,很显然,这种理解是不对的,不是链接的超时时间。 简单概括起来,应该是:读取数据时阻塞链路的超时时间。

上面Socket的setSoTimeout的文档翻译后的内容为:
setSoTimeout public void setSoTimeout(int timeout) throws SocketException启用/
禁用带有指定超时值的 SO_TIMEOUT,以毫秒为单位。将此选项设为非零的超时值时,在与此 Socket 关联的 InputStream 上调用
read() 将只阻塞此时间长度。 如果超过超时值,将引发 java.net.SocketTimeoutException,虽然 Socket
仍旧有效。选项必须在进入阻塞操作前被启用才能生效。 超时值必须是> 0 的数。超时值为 0 被解释为无穷大超时值。 参数: timeout -
指定的以毫秒为单位的超时值。 抛出: SocketException- 如果底层协议出现错误,例如 TCP 错误。
最简单的测试验证的方法是:

写一个基于Socket的下载方法,设置setSoTimeout后,下载一个大文件,会发现,下载的时间超过setSoTimeout的值之后,就会失败!!