其實第二個重構保持Provider的名字改動很小。 ``` @@ -1,7 +1,6 @@ package geektime.tdd.di; import jakarta.inject.Inject; -import jakarta.inject.Provider; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; @@ -16,8 +15,12 @@ import static java.util.Arrays.stream; public class ContextConfig { private Map<Class<?>, Provider<?>> providers = new HashMap<>(); + interface Provider<T> { + T get(Context context); + } + public <T> void bind(Class<T> type, T instance) { - providers.put(type, (Provider<T>) () -> instance); + providers.put(type, (Provider<T>) context -> instance); } public <T, Impl extends T> void bind(Class<T> type, Class<Impl> implementation) { @@ -30,7 +33,7 @@ public class ContextConfig { return new Context() { @Override public <T> Optional<T> get(Class<T> type) { - return Optional.ofNullable(providers.get(type)).map(p -> (T) p.get()); + return Optional.ofNullable(providers.get(type)).map(p -> (T) p.get(this)); } }; } @@ -46,12 +49,12 @@ public class ContextConfig { } @Override - public T get() { + public T get(Context context) { if (constructing) throw new CyclicDependenciesFound(type); try { constructing = true; Object[] dependencies = stream(constructor.getParameters()) - .map(p -> getContext().get(p.getType()).orElseThrow(() -> new DependencyNotFoundException(type, p.getType()))) + .map(p -> context.get(p.getType()).orElseThrow(() -> new DependencyNotFoundException(type, p.getType()))) .toArray(Object[]::new); return (T) constructor.newInstance(dependencies); } catch (CyclicDependenciesFound e) { ```