Guice AssistedInject

GuiceExploratoryTest.java

import com.google.inject.AbstractModule;
import com.google.inject.Guice;
import com.google.inject.Inject;
import com.google.inject.Injector;
import com.google.inject.assistedinject.Assisted;
import com.google.inject.assistedinject.FactoryModuleBuilder;
import org.junit.Test;

import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

public class GuiceExploratoryTest {
    private static final String VALUE_ASSISTED_NAME = "value";

    @Test
    public void instantiateFactory() {
        final Injector injector = Guice.createInjector(new Module());

        final AoeuFactory aoeuFactory = injector.getInstance(AoeuFactory.class);
        final Aoeu aoeu = aoeuFactory.create("aoeu");

        assertThat(aoeu.getValueKnownByTheCreatorOfAoeuClass(), is("aoeu"));
    }

    public static class Module extends AbstractModule {
        @Override
        protected void configure() {
            install(new FactoryModuleBuilder()
                    .implement(Aoeu.class, Aoeu.class)
                    .build(AoeuFactory.class));
        }
    }

    public static class Aoeu {
        private final DependencyInjectedTheUsualWay dependencyInjectedTheUsualWay;
        private final String valueKnownByTheCreatorOfAoeuClass;

        @Inject
        public Aoeu(
                final DependencyInjectedTheUsualWay dependencyInjectedTheUsualWay,
                @Assisted(VALUE_ASSISTED_NAME) final String valueKnownByTheCreatorOfAoeuClass) {
            this.dependencyInjectedTheUsualWay = dependencyInjectedTheUsualWay;
            this.valueKnownByTheCreatorOfAoeuClass = valueKnownByTheCreatorOfAoeuClass;
        }

        public String getValueKnownByTheCreatorOfAoeuClass() {
            return valueKnownByTheCreatorOfAoeuClass;
        }
    }

    public static interface AoeuFactory {
        public Aoeu create(
                @Assisted(VALUE_ASSISTED_NAME) final String string);
    }

    private static class DependencyInjectedTheUsualWay {}
}