Why would a “java.net.ConnectException: Connection timed out” exception occur when URL is up?

Question

I\'m getting a ConnectException: Connection timed out with some frequency from my code. The URL I am trying to hit is up. The same code works for some users,

Answer 1

There is a possibility that your IP/host are blocked by the remote host, especially if it thinks you are hitting it too hard.

Answer 2

The error message says it all: your connection timed out. This means your request did not get a response within some (default) timeframe. The reasons that no response was received is likely to be one of:

a) The IP/domain or port is incorrect

b) The IP/domain or port (i.e service) is down

c) The IP/domain is taking longer than your default timeout to respond

d) You have a firewall that is blocking requests or responses on whatever port you are using

e) You have a firewall that is blocking requests to that particular host

f) Your internet access is down

g) Your live-server is down i.e in case of "rest-API call".

Note that firewalls and port or IP blocking may be in place by your ISP

Answer 3

I'd recommend raising the connection timeout time before getting the output stream, like so:

urlConnection.setConnectTimeout(1000);

Where 1000 is in milliseconds (1000 milliseconds = 1 second).

Answer 4

I solved my problem with:

System.setProperty("https.proxyHost", "myProxy");
System.setProperty("https.proxyPort", "80");

or http.proxyHost...