Pass parameter to constructor with Guice

Question

I have a factory as below,

public final class Application {

    private static IFoo foo;

    public static IFoo getFoo(String bar)
    {
        // i need         


        

Answer 1

I know that this is old thread but I just hit the issue myself today. I only need two or maximum three different instances of 'Foo' and I really didn't want to write all the bolierplate code of Factory. With a little googling I found this Stubbisms – Tony’s Weblog I would suggest this solution which is perfect if you know exactly what instances you need.

In Guice module:

    bind(Foo.class).annotatedWith(Names.named("firstFoo")).toProvider(new Provider() {
        @Override
        public Foo get() {
            return new FooImpl("topic A");
        }
    });
    bind(Foo.class).annotatedWith(Names.named("secondFoo")).toProvider(new Provider() {
        @Override
        public Foo get() {
            return new FooImpl("topic B");
        }
    });

Or in java 8:

    bind(Foo.class).annotatedWith(Names.named("firstFoo")).toProvider(() -> new FooImpl("first"));
    bind(Foo.class).annotatedWith(Names.named("secondFoo")).toProvider(() -> new FooImpl("second"));

And in constructor of your service where you need Foo instances:

@Inject
public MyService (
    @Named("firstFoo") Foo firstFoo,
    @Named("secondFoo") Foo secondFoo) {
}

And Foo in my case:

public class FooImpl implements Foo {

    private String name;

    public FooImpl(String name) {
        this.name = name;
    }

    @Override
    public String getName() {
        return name;
    }
}

Hope it helps someone.