Question

我想将MyImpl绑定到Multibinding。但是MyImpl的构造函数带有参数。

var currentUserChats = [Chat]() {
    didSet(newValue){
       attachChildChangedObserverOn(chat: newValue)
    }
}

var observersArray = [String: UInt]() // chatUID:handle


  func attachChildChangedObserverOn(chat: Chat) {

     var handle: UInt = 0
     let ref =   DDatabaseRReference.chats.reference().child(chat.chatUID).child("users").child(currentUser.userUID)
    handle = ref.observe(.childChanged, with: {[weak self] (snapshot) in

     self?.observersArray[chat.chatUID] = handle

        print("snapshot.value is \(snapshot.value) and snapKey is \(snapshot.key)")
        guard snapshot.exists() else {return}

        let chatChanged = chat

        var lastMessage = ""
        var unreadMessagesCount = 0
        var lastUpdate = 0.0

        switch snapshot.key {
        //case....
       }

     })

  }

我不想@Inject它，因为它是布尔值，可以偶尔将其注入其他地方。所以。我可以介绍一些Enum并注入它，然后怎么做呢？或者我可以更好地写

final Multibinder<MyInterface> binder = Multibinder.newSetBinder(binder(), MyInterface.class)
binder.addBinding().to(MyImpl.class);

public MyImpl(Boolean myParam) ...

等等？

Answer 1

我不想@Inject它，因为它是布尔值，可以偶尔将其注入其他地方。为避免这种情况，请使用“命名注释”。

解决方案一：

@Inject
public TextEditor(@Named("OpenOffice") SpellChecker spellChecker) { ...}

这是绑定代码：

bind(SpellChecker.class).annotatedWith(Names.named("OpenOffice")).to(OpenOfficeWordSpellCheckerImpl.class);

解决方案二：

在模块中加载java-properties并使用java-prop-names：

private static Properties loadProperties(String name){
    Properties properties = new Properties();
    ClassLoader loader = Thread.currentThread().getContextClassLoader();
    InputStream is = loader.getResourceAsStream(name);
    try {
        properties.load(is);
    } catch (IOException e) {
        throw new RuntimeException(e);
    }finally {
        if(is != null){
            try {
                is.close();
            } catch (IOException dontCare) { }
        }
    }
    return properties;
}

protected void configure() {
    try{
        Properties gameProperties = loadProperties("game.properties");
        Names.bindProperties(binder(),gameProperties);
    }catch (RuntimeException ex){
        addError("Could not configure Game Properties");
    };

}

如何在Guice中将类与构造函数绑定

1 个答案: