GUICE：注入值取決於範圍

Question

我有一個控制器類。

這個類需要一個不同的枚舉值，這取決於它被注入的位置。我不想爲控制器創建子類。

我該怎麼做？

例子：

class FirstItem { 

    //some of these have an injected controller which needs the enum value 'FIRST' 
    @Inject 
    @FirstSubItems //Custom annotation for multibinding 
    Set<Item> subItems; 
} 

class SecondItem { 

    //some of these have an injected controller which needs the enum value 'SECOND' 
    @Inject 
    @SecondSubItems //Custom annotation for multibinding 
    Set<Item> subItems; 
} 

class Controller { 
    @Inject 
    MyEnum enumValue; 
} 

可以這樣做優雅？我將如何配置模塊？

模塊看起來像目前這樣：

Multibinder<Item> toolsSectionOne = Multibinder.newSetBinder(binder, Item.class, FirstSubItems.class); 
toolsSectionOne.addBinding().to(Item1.class); 
toolsSectionOne.addBinding().to(Item2.class); 

Multibinder<Item> toolsSectionTwo = Multibinder.newSetBinder(binder, Item.class, SecondSubItems.class); 
toolsSectionTwo.addBinding().to(Item1.class); 
toolsSectionTwo.addBinding().to(Item2.class); 

Answer 1

我已經解決了我的問題與PrivateBinder：

Type type = TypeLiteral.get(Item.class).getType(); 
Type setType = Types.setOf(type); 

PrivateBinder privateBinderOne = binder.newPrivateBinder(); 
privateBinderOne.bind(MyEnum.class).toInstance(MyEnum.FIRST); 
Multibinder<Item> toolsSectionOne = Multibinder.newSetBinder(privateBinderOne , Item.class, FirstSubItems.class); 
toolsSectionOne.addBinding().to(Item1.class); 
toolsSectionOne.addBinding().to(Item2.class); 
privateBinderOne.expose(Key.get(setType, FirstSubItems.class)); 

PrivateBinder privateBinderTwo = binder.newPrivateBinder(); 
privateBinderTwo.bind(MyEnum.class).toInstance(MyEnum.SECOND); 
Multibinder<Item> toolsSectionTwo = Multibinder.newSetBinder(privateBinderTwo , Item.class, SecondSubItems.class); 
toolsSectionTwo.addBinding().to(Item1.class); 
toolsSectionTwo.addBinding().to(Item2.class); 
privateBinderTwo.expose(Key.get(setType, SecondSubItems.class)); 

這就像一個魅力。