That's not what usually is considered network traffic. Those solutions are to intercept the Java stream used for the HTTP traffic of Spring MVC. You mention using Spring but not Spring MVC explicitly. In any case to capture network traffic without any coding you could use a packet capture tool, like Wireshark. Note that you will not be able to decrypt HTTPS out of the box. It requires some extra configurations and access to secret keys.
Another option for HTTP traffic is to enable Java SSL debug log. It can be very verbose but you don't need extra steps or learn a new tool.