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Dropwizard commands support

Guice injections

Guicey calls injector.injectMembers(command) for all registered EnvironmentCommands, so you can inject guice beans directly:

public class MyCommand extends EnvironmentCommand<MyConfiguration> {

    @Inject
    private MyService myservice;

    public MyCommand(Application application) {
        super(application, "mycli", "my super useful cli");
    }

    @Override
        protected void run(Environment environment, 
                             Namespace namespace, 
                             MyConfiguration configuration) throws Exception { 
            myservice.doSomething();        
        }
}

Note

It doesn't matter if command was registered manually, by some bundle or with commands search (see below).

Warning

You can use guice injections only in EnvironmentCommands because only these commands start bundles (and so launch guice context creation).

Automatic installation

Automatic scan for commands is disabled by default. It could be enabled by:

GuiceBundle.builder()
    .enableAutoConfig("package.to.scan")
    .searchCommands()

When enabled, all classes extending Command are instantiated using default constructor and registered in dropwizard bootstrap object.

Simple commands

For example, if command below would be inside scanned package, then guicey will automatically register it.

public class MyCommand extends Command {

    public MyCommand() {
        super("hello", "Prints a greeting");
    }

    @Override
    public void run(Bootstrap<?> bootstrap, Namespace namespace) throws Exception {
        System.out.println("Hello world");
    }
}

Environment commands

Important

EnvironmentCommand must have constructor with Application argument.

public class SyncCommand extends EnvironmentCommand<AppConfiguration> {

    @Inject
    private RemoteSynchronizer synchronizer;
    @Inject
    private DbManager manager;

    public SyncCommand(Application<AppConfiguration> application) {
        super(application, "sync", "Perform remote synchronization");
    }

    @Override
    protected void run(Environment environment, 
                        Namespace namespace, 
                        AppConfiguration configuration) throws Exception {
        manager.start();
        try {
            synchronizer.synchronize();
        } finally {
            manager.stop();
        }
    }
}

This example shows workaround for managed initialization in commnads: DbManager is some Managed bean which would run automatically in server mode. But commands never call managed objects, so we have to manually start and stop them.