java - Grails - 无法从 Controller 调用服务 --> 总是得到 "Cannot invoke method on null object error"

Question

我有一个 grails 应用程序，我正在按照此处的教程进行操作:
http://www.grails.org/Services

我有一些代码，例如

import org.springframework.beans.factory.InitializingBean

class SubmitRequestService implements InitializingBean{
    def GrailsApplication1
    def setting

    void afterPropertiesSet(){
        this.setting = GrailsApplication1.config.setting
    }

    def void sendHistoricalContract(HistoricalContract hc_instance){
        //... blah blah whatever code      
    }
}

class SubmitRequestController {    
    def submitRequestService
    static allowedMethods = [save: "POST", update: "POST", delete: "POST"]

    def index = {
        // .... blah blah whatever code
        submitRequestService.sendHistoricalContract(historicalContractInstance)
    }    
}

不，无论我做什么，我似乎都无法将服务注入(inject)到 Controller 中。每当我到达调用服务的行时，我都会收到错误:

ERROR errors.GrailsExceptionResolver - Cannot invoke method sendHistoricalContract() on null object

我做错了什么？

提前致谢

Answer 1

GrailsApplication1 看起来很奇怪 - 这是从哪里来的？如果您想访问 GrailsApplication 实例来获取配置，请对 grailsApplication Spring bean 使用依赖项注入(inject):

class SubmitRequestService implements InitializingBean {

   private setting

   def grailsApplication

   void afterPropertiesSet() {
       setting = grailsApplication.config.setting
   }

   void sendHistoricalContract(HistoricalContract hc_instance) {
      //... blah blah whatever code      
   }
}

我的猜测是 GrailsApplication1 导致服务出现问题，导致其无法注入(inject) Controller ，但我认为它会在启动时因异常而崩溃。尝试运行 grails clean 来强制完全重新编译。