java - What is the functionality of setSoTimeout and how it works?

Question

I'm trying to learn Socket by myself. I'm little bit confused by following text from Oracle website. I have some questions regarding that. Thanks in advance for any clear explanation.

setSoTimeout

public void setSoTimeout(int timeout) throws SocketException

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 of time. 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.

1. What is SO_TIMEOUT?

2. Socket is the endpoint of a connection. If I say

   mySocket.setSoTimeout(2000);
   

   Does it mean that I'm blocking reading any input from the Server/Client for this socket for 2000 millisecond and after this time the socket is ready to read data?

3. What does it mean timeout expire?

4. What is the option which must be enabled prior to blocking operation?

5. Infinite Timeout means that the socket does't read anymore?

Answer 1

Does it mean that I'm blocking reading any input from the Server/Client for this socket for 2000 millisecond and after this time the socket is ready to read data?

No, it means that if no data arrives within 2000ms a SocketTimeoutException will be thrown.

What does it mean timeout expire?

It means the 2000ms (in your case) elapses without any data arriving.

What is the option which must be enabled prior to blocking operation?

There isn't one that 'must be' enabled. If you mean 'may be enabled', this is one of them.

Infinite Timeout menas that the socket does't read anymore?

What a strange suggestion. It means that if no data ever arrives you will block in the read forever.