Bean的Spring静态初始化

问题描述

嘿，Spring应该如何处理静态初始化?我的意思是，我的bean有一个静态初始化

Hey,how one should deal with static initializations in Spring ? I mean, my bean has a static initialization

private static final Map<String, String> exceptionMapping = ErrorExceptionMapping.getExceptionMapping();

而且我需要注意ErrorExceptionMapping之前已加载.我试过了:

And I need to take care that ErrorExceptionMapping is loaded before. I tried this:

<bean id="errorExceptionMapping" class="cz.instance.transl.util.ErrorExceptionMapping" />
<bean id="validateService" class="cz.instance.transl.services.ValidateService" depends-on="errorExceptionMapping" >

但我知道了

java.lang.NoClassDefFoundError: Could not initialize class cz.instance.transl.util.ErrorExceptionMapping

如果我省略了静态初始化或从bean的方法中调用该方法，那么它当然很好.我想初始化回调(affterPropertiesSet())在这里无济于事.

If I omit the static initialization or call the method from within the bean's method, its of course fine. I suppose that Initialization callback (affterPropertiesSet()) wouldn't help here.

推荐答案

对其他bean具有static依赖项不是Spring的方法.

Having static dependencies on other beans is not a Spring way.

但是，如果要保留它static，则可以延迟对其进行初始化-在这种情况下，depends-on可以强制执行正确的初始化顺序.

However, if you want to keep it static, you can initialize it lazily - in that case depends-on can enforce proper initialization order.

通过延迟加载，我的意思是这样的(我在这里将懒惰的初始化与holder类的习惯用法结合使用，也可以使用其他的懒惰的初始化习惯用法):

By lazy loading I mean something like this (I use lazy initialization with holder class idiom here, other lazy initialization idioms can be used instead):

private static class ExceptionMappingHolder {
    private static final Map<String, String> exceptionMapping =
        ErrorExceptionMapping.getExceptionMapping();
}

，并使用ExceptionMappingHolder.exceptionMapping代替exceptionMapping.

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