调用 API 时 I/O 超时异常 (java.net.ConnectException)

Question

I'm using HttpClient in order to call an API and get its response, and I have set a 60 secs timeout. In this 60 seconds, Java try and retry to connect to the API by each 20 seconds and shows the exception. In the final of 60 secs, it stops retrying.

My doubt is: this I/O Exception is caused by the API? Since I set a timeout higher than the exception returns (each 20 seconds).

Here's the code and the log:

HttpClient client = new HttpClient();
GetMethod getMethod = new GetMethod(GET_TICKETS_URL);
getMethod.setRequestHeader("Content-Type", "application/json");
getMethod.setRequestHeader("Accept", "application/json");
getMethod.getParams().setSoTimeout(60000);
logger.info("Calling service: " + getMethod.getPath());

client.getHttpConnectionManager().getParams().setConnectionTimeout(60000);
client.getHttpConnectionManager().getParams().setSoTimeout(60000);
client.getParams().setSoTimeout(60000);
client.getParams().setConnectionManagerTimeout(60000);

int getTicketsResponse = client.executeMethod(getMethod);

[2020-08-27 13:41:25,215] pool-3-thread-1 br.com.pfm.tasks.baml.task Task INFO  - Calling service: /
[2020-08-27 13:41:46,228] pool-3-thread-1 org.apache.commons.httpclient.HttpMethodDirector INFO  - I/O exception (java.net.ConnectException) caught when processing request: Connection timed out: connect
[2020-08-27 13:41:46,228] pool-3-thread-1 org.apache.commons.httpclient.HttpMethodDirector INFO  - Retrying request
[2020-08-27 13:42:07,242] pool-3-thread-1 org.apache.commons.httpclient.HttpMethodDirector INFO  - I/O exception (java.net.ConnectException) caught when processing request: Connection timed out: connect
[2020-08-27 13:42:07,242] pool-3-thread-1 org.apache.commons.httpclient.HttpMethodDirector INFO  - Retrying request
[2020-08-27 13:42:28,258] pool-3-thread-1 org.apache.commons.httpclient.HttpMethodDirector INFO  - I/O exception (java.net.ConnectException) caught when processing request: Connection timed out: connect
[2020-08-27 13:42:28,258] pool-3-thread-1 org.apache.commons.httpclient.HttpMethodDirector INFO  - Retrying request
[2020-08-27 13:42:49,271] pool-3-thread-1 br.com.pfm.tasks.baml.task ERROR - java.net.ConnectException: Connection timed out: connect

Answer 1

I/O exception is occur when there is an issue in reading from the url, can you able to get the stack stacktrace, will give an insight about the issue, it could be the server unavailable or not found anything from http 400+

so please add this to your catch block and will help you get an idea, what went wrong.

catch(Exception e)
{
   e.printStacktrace();
}

Answer 2

Based on the somewhat incomplete information presented here, a stack trace will likely reveal the point of failure is where you try to kick off the HTTP transaction (actually tell it to go a head and connect).

Assuming that you've set everything up correctly in GetMethod (and I cant tell), may i recomend that you check that the target you are trying to reach, is actually reachable from the machine? try a wget or if its on a desk top try to access it with your browser. If that works, its likely you set things up incorrectly in your GetMethod code - posting that would be very helpful to troubleshoot further.