There are multiple spring boot application working on the same server. On spring boot application A there is an apache camel route that has been stopped. On spring boot application B there is a service that after it finishes it needs to start the apache camel route in application A. Is it possible to achieve this?
If you have route you need to start from any external application or service you can expose a rest-api from your Application A with rest endpoint that will start the desired route when requested.
Not only will this allow you to signal Application A the route from another camel application like your Application B but from many other services as well. Since both applications are on the same server you can restConfiguration().host("localhost") to limit connections to local ones.
Alternative would be to use message broker like ActiveMQ artemis to pass messages between different applications using jms.
I generally would avoid any solutions where one would enable disabled routes. Not only are those messy to implement but also very inflexible and hard to test. With Apache camel you'd probably need use JMX to enable disabled routes.