Best practices for using jersey client via guice injection

Question

I'm using Jersey-2.19.x in my application to call rest APIs. Since jersey clients are expensive to create, I wanted to reuse the client for my API calls and therefore inject the client via guice injection.

Here is my guice code for injecting jersey client:

@Provides
@Singleton
Client getClient() {
  return ClientBuilder.newClient();
}

And here is my class that uses this injection:

@Inject
public MyClass(Client client) {
  this.client = client;
}

public callPost(String uri) {
  // code to set web target and invoke
}

Now my question is, how can I close this injected client? What happens if jersey clients are never closed? And what are some best practices for using jersey client via dependency injection?

According to Guice documentation you should avoid injecting closable resources. Here you can find the detailed explanation and the possible workarounds. https://github.com/google/guice/wiki/Avoid-Injecting-Closable-Resources — olgacosta, Sep 04 '19 at 14:08

score 0 · Answer 1 · answered Sep 06 '19 at 07:38

You need a shutdown hook.

Here is a good article that might be somewhat of an overkill for your situation: https://richardstartin.github.io/posts/lifecycle-management-with-guice-provision-listeners

If you want to keep things simpler, and you don't need to close anything but the Jersey client, you could try something like this:

public static void main(String args[]) {
  Injector injector = Guice.createInjector(/* modules... */);
  Client jerseyClient = injector.getInstance(Client.class);
  Runtime.getRuntime().addShutdownHook(new Thread() {
    @Override public void run() { 
      jerseyClient.close(); 
    }
  });
  // proceed as normal
}

Best practices for using jersey client via guice injection

1 Answers1