为什么使用@PostConstruct? [英] Why use @PostConstruct?

问题描述

在托管 bean 中，@PostConstruct 在常规 Java 对象构造函数之后调用.

In a managed bean, @PostConstruct is called after the regular Java object constructor.

为什么我要使用 @PostConstruct 来通过 bean 初始化，而不是使用常规构造函数本身?

Why would I use @PostConstruct to initialize by bean, instead of the regular constructor itself?

推荐答案

• 因为在调用构造函数时，bean 尚未初始化 - 即没有注入依赖项.在 @PostConstruct 方法中，bean 已完全初始化，您可以使用依赖项.

  • because when the constructor is called, the bean is not yet initialized - i.e. no dependencies are injected. In the @PostConstruct method the bean is fully initialized and you can use the dependencies.

    因为这是保证这个方法在 bean 生命周期中只会被调用一次的契约.容器在其内部工作中可能会(尽管不太可能)多次实例化 bean，但它保证 @PostConstruct 只会被调用一次.

    because this is the contract that guarantees that this method will be invoked only once in the bean lifecycle. It may happen (though unlikely) that a bean is instantiated multiple times by the container in its internal working, but it guarantees that @PostConstruct will be invoked only once.

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