spring - 在 Controller 内部构造时，将服务自动连线到Grails中的命令对象的正确方法

我有这样的代码...

@Validateable
class RecipientsCommand {
 ...
 EmailService emailService
 void getEmailEligibleRecipients(Long accountId){
    emailService.loadEligibleEmail(accountId)
 }
}

资源

imports com.test.commands.RecipientsCommand
beans = {
 recipientsCommand(RecipientsCommand){bean -> bean.autowire = true}
}

但是当我打电话时服务仍然总是为空

new RecipientCommand()

由于命令对象似乎是 View 和 Controller 之间的接口(interface)，因此我将其创建，填充并将其传递给 View 。然后，我用它来解析和保存数据。如果我改成...

EmailService emailService = new EmailService()

一切正常。

最佳答案

自动连线仅在Grails为您创建实例时发生。您不能只是new RecipientCommand()并期望Spring参与其中。如果您从Spring应用程序上下文中检索recipientsCommand bean，它将被自动连接，并且如果RecipientCommand由框架创建并作为参数传递给您的 Controller 操作，那么它也将被自动连接。调用new RecipientCommand()构造函数将导致创建一个新实例，该实例不会自动连接。

编辑:

例子...

class SomeController {
    def someAction(RecipientCommand co) {
        // co will already be auto wired
        // this approach does NOT require you to have defined the
        // recipientsCommand bean in resources.groovy
    }
}

class SomeOtherController {
    def someAction() {
        // rc will be autowired
        // this approach requires you to have defined the
        // recipientsCommand bean in resources.groovy
        def rc = grailsApplication.mainContext.getBean('recipientsCommand')
    }
}

class AnotherSomeOtherController {
    def recipientsCommand

    def someAction() {
        // recipientsCommand will be auto wired
        // this approach requires you to have defined the
        // recipientsCommand bean in resources.groovy
    }
}

class YetAnotherController {
    def someAction() {
        // rc will not be autowired
        def rc = new RecipientCommand()
    }
}

希望对您有所帮助。

关于spring - 在 Controller 内部构造时，将服务自动连线到Grails中的命令对象的正确方法，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/24411841/