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Guice辅助注射

assisted-inject inject guice dependency-injection java

1

Andrei Koch · 技术社区 · 8 年前

我是Guice的新手,所以我在试着理解AssistedInject。我有一个非常简单的项目:

public class I1 {
}

辅助注射类:

public interface ICla {
}

public class Cla implements ICla{
    public Integer t;
    public I1 i;

    @Inject
    public Cla(Integer t, @Assisted I1 i) {
        this.t = t;
        this.i = i;

    }
}

工厂

public interface IClaFactory {
    Cla create(Integer t);
}

主要课程:

public class Main {
    public static void main(String[] args) {
        Injector injector = Guice.createInjector(new Module());

        IClaFactory factory = injector.getInstance(IClaFactory.class);
    }

    private static class Module extends AbstractModule {
        protected void configure() {
            install(new FactoryModuleBuilder()
                .implement(ICla.class, Cla.class).build(IClaFactory.class));
        }
    }
}

但它仍然不起作用,我不明白,我错在哪里?

Exception in thread "main" com.google.inject.CreationException: Unable to create injector, see the following errors:

1) No implementation for ru.test.factory.I1 annotated with @com.google.inject.assistedinject.Assisted(value=) was bound.
  while locating ru.test.factory.I1 annotated with @com.google.inject.assistedinject.Assisted(value=)
    for parameter 1 at ru.test.factory.Cla.<init>(Cla.java:11)
  at ru.test.factory.IClaFactory.create(IClaFactory.java:1)
  at com.google.inject.assistedinject.FactoryProvider2.initialize(FactoryProvider2.java:660)
  at com.google.inject.assistedinject.FactoryModuleBuilder$1.configure(FactoryModuleBuilder.java:335) (via modules: ru.test.Main$Module -> com.google.inject.assistedinject.FactoryModuleBuilder$1)

2) Could not find a suitable constructor in java.lang.Integer. Classes must have either one (and only one) constructor annotated with @Inject or a zero-argument constructor that is not private.
  at java.lang.Integer.class(Integer.java:52)
  while locating java.lang.Integer
    for parameter 0 at ru.test.factory.Cla.<init>(Cla.java:11)
  at ru.test.factory.IClaFactory.create(IClaFactory.java:1)
  at com.google.inject.assistedinject.FactoryProvider2.initialize(FactoryProvider2.java:660)
  at com.google.inject.assistedinject.FactoryModuleBuilder$1.configure(FactoryModuleBuilder.java:335) (via modules: ru.test.Main$Module -> com.google.inject.assistedinject.FactoryModuleBuilder$1)

1 回复 | 直到 8 年前

1

2

Olivier Grégoire 8 年前

你是 @Assisted -输入错误参数:要“辅助”的参数是在工厂界面中定义的参数。在这种情况下,这是你的 Integer ,而不是您的 I1 .

这将起作用:

@Inject
public Cla(I1 i, @Assisted Integer t) {
    this.t = t;
    this.i = i;

}