在域类中使用 grails 服务 [英] Using grails service in domain class

问题描述

我想在我的 Grails 应用程序中使用一个服务.但是，它始终为空.我正在使用 Grails 1.1 版.我该如何解决这个问题?

I want to use a service in my Grails application. However, it is always null. I am using Grails version 1.1. How can I solve this problem?

示例代码:

 class A{
      String name;
      def testService;
      static transients=['testService']
 }

我可以在域类中使用服务吗?

Can I use a service inside a domain class?

推荐答案

那应该可行.请注意，由于您使用的是def"，因此无需将其添加到瞬态列表中.您是否尝试从静态方法访问它?它是一个实例字段，因此您只能从实例中访问它.

That should work. Note that since you're using 'def' you don't need to add it to the transients list. Are you trying to access it from a static method? It's an instance field, so you can only access it from instances.

将服务注入域类的典型用例是用于验证.自定义验证器通过正在验证的域类实例，因此您可以从中访问服务:

The typical use case for injecting a service into a domain class is for validation. A custom validator gets passed the domain class instance being validated, so you can access the service from that:

static constraints = {
   name validator: { value, obj ->
      if (obj.testService.someMethod(value)) {
         ...
      }
   }
}

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