I have the following APIs defined:
public interface Input<I> { Collection<? extends I> read(); } public interface Transformer<O, I> { Collection<? extends O> transform(Collection<? extends I> inputData); } public interface Output<O> { void write(Collection<? extends O> output); } public interface Executor { void execute(); } and the following implementations:
public final class InputImpl implements Input<String> { @Override public Collection<? extends String> read() { return asList("1", "2"); } } public final class TransformerImpl implements Transformer<Integer, String> { @Override public Collection<? extends Integer> transform(final Collection<? extends String> inputData) { return inputData.stream().map(Integer::parseInt).collect(Collectors.toList()); } } public final class OutputImpl implements Output<Integer> { @Override public void write(final Collection<? extends Integer> output) { System.out.println(output); } } public final class ExecutorImpl<I, O> implements Executor { private final Input<I> input; private final Transformer<O, I> transformer; private final Output<O> output; @Inject public ExecutorImpl(final Input<I> input, final Transformer<O, I> transformer, final Output<O> output) { this.input = input; this.transformer = transformer; this.output = output; } public void execute() { final Collection<? extends I> inputData = input.read(); final Collection<? extends O> outputData = transformer.transform(inputData); output.write(outputData); } } Here is my attempt to bind the APIs to the implementations from above:
public final class ModuleImpl extends AbstractModule { @Override protected void configure() { bind(new TypeLiteral<Input<String>>() { }).to(InputImpl.class); bind(new TypeLiteral<Transformer<Integer, String>>() { }).to(TransformerImpl.class); bind(new TypeLiteral<Output<Integer>>() { }).to(OutputImpl.class); bind(Executor.class).to(ExecutorImpl.class); } } When I am trying to get an instance of Executor using a Guice injector, I am getting the following errors:
1) com.csc.playground.guice.api.Input<I> cannot be used as a key; It is not fully specified. at com.csc.playground.guice.ExecutorImpl.<init>(ExecutorImpl.java:25) at com.csc.playground.guice.module.ModuleImpl.configure(ModuleImpl.java:33) 2) com.csc.playground.guice.api.Transformer<O, I> cannot be used as a key; It is not fully specified. at com.csc.playground.guice.ExecutorImpl.<init>(ExecutorImpl.java:25) at com.csc.playground.guice.module.ModuleImpl.configure(ModuleImpl.java:33) 3) com.csc.playground.guice.api.Output<O> cannot be used as a key; It is not fully specified. at com.csc.playground.guice.ExecutorImpl.<init>(ExecutorImpl.java:25) at com.csc.playground.guice.module.ModuleImpl.configure(ModuleImpl.java:33) 
injector.getInstance(Executor.class)inject intoExecutorImpl, if you have boundOutputfor several generic parameters? This is perfectly valid in Guice, because type literals will be different.