java - Guice 多重绑定(bind) : Manually obtain a Set from Injector

Question

使用 guice Multibindings 扩展可以注入(inject)特定类型的集合而不是该类型的单个实例。我如何使用 Injector.getInstance(...) 从 Injector 手动获取此 Set？到目前为止，我的尝试导致了带有消息的 ConfigurationException:

java.util.Set<T> cannot be used as a key; It is not fully specified.

public final <T> Iterator<T> loadServices(Class<T> type) {
    final TypeLiteral<Set<T>> lit = new TypeLiteral<Set<T>>() {};
    final Key<Set<T>> key = Key.get(lit);
    final Set<T> bindings = this.injector.getInstance(key);
    return bindings.iterator();
}

Answer 1

我使用这个片段创建了一个 TypeLiteral<Set<T>> :

import com.google.inject.util.Types;

@SuppressWarnings("unchecked")
public static <T> TypeLiteral<Set<T>> setOf(Class<T> type) {
    return (TypeLiteral<Set<T>>)TypeLiteral.get(Types.setOf(type));
}

我这里还有其他一些类似的便利:https://github.com/tavianator/sangria/blob/master/sangria-core/src/main/java/com/tavianator/sangria/core/TypeLiterals.java