后期创建初始化guice singleton [英] Post creation initialization of guice singleton

问题描述

有没有办法让guice在实例化单例后调用init（）方法？在构造函数中调用init（）不是一个选项，因为init（）可以被子类覆盖。

Is there a way to have guice call a init() method after it has instantiated a singleton? Calling init() inside the constructor is not an option since init() could be overriden by a subclass.

推荐答案

你可以使用当你使用 mycila / jsr250扩展时，`@ PostConstruct'就会出现问题。这将导致在实例化后立即调用init（）方法。

You can use `@PostConstruct' in guice when you use the mycila/jsr250 extension. This will cause your init() method to be called right after instantiation.

@PostConstruct
void init() {
     // ...
}

如果你不能/想要为此添加第三方库，我写了一个简单的 postconstruct模块对于此以及不久前：

If you do not can/want to add 3rd party libs for this, I wrote a simple postconstruct module for this as well a while ago:

public enum PostConstructModule implements Module, TypeListener {

INSTANCE;

@Override
public void configure(final Binder binder) {
    // all instantiations will run through this typeListener
    binder.bindListener(Matchers.any(), this);
}

/**
 * Call postconstruct method (if annotation exists).
 */
@Override
public <I> void hear(final TypeLiteral<I> type, final TypeEncounter<I> encounter) {
    encounter.register(new InjectionListener<I>() {

        @Override
        public void afterInjection(final I injectee) {
            for (final Method postConstructMethod : filter(asList(injectee.getClass().getMethods()), MethodPredicate.VALID_POSTCONSTRUCT)) {
                try {
                    postConstructMethod.invoke(injectee);
                } catch (final Exception e) {
                    throw new RuntimeException(format("@PostConstruct %s", postConstructMethod), e);
                }
            }
        }
    });
   }
  }

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