在 Grails 控制器中包含具有会话范围的服务？

Question

使用 Grails 2.4.5 我有以下服务：

class CartService {

    static scope = 'session'
    static proxy = true

    def items = []

    def getItemCount() {
        items.size()
    }

}

我想在控制器中使用此服务：

class CartController {

    def cartService // unique per session

    def addItem = {
        cartService.items << new CartItem(product: Product.get(params.id))
    }

}

我尝试了 Grails scoped-proxy plugin 的 0.3 版。但是我收到以下错误：

Error creating bean with name 'cartService': Scope 'session' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
    Line | Method
->>  262 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|   1145 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Caused by BeanCreationException: Error creating bean with name 'cartService': Scope 'session' is not active for the current thread; consider defining a scoped proxy for this bean if you intend to refer to it from a singleton; nested exception is java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
->>  262 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|   1145 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread
Caused by IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? If you are actually operating within a web request and still receive this message, your code is probably running outside of DispatcherServlet/DispatcherPortlet: In this case, use RequestContextListener or RequestContextFilter to expose the current request.
->>  262 | run       in java.util.concurrent.FutureTask
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
|   1145 | runWorker in java.util.concurrent.ThreadPoolExecutor
|    615 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
^    745 | run       in java.lang.Thread

如何在 Grails 控制器中包含具有会话范围的服务？

Answer 1

看起来您可能发现了 Grails 2 插件的一两个问题（也已报告）。4.x。如果是这样的话，可以参考插件作者的一篇博客post：Scoped Services & Proxies in Grails.

在那里，他展示了如何在没有插件的情况下做到这一点。我试了一下，它在 2.4.5 中有效。

resources.groovy:

import org.springframework.aop.scope.ScopedProxyFactoryBean

beans = {
    cartServiceProxy(ScopedProxyFactoryBean) {
        targetBeanName = 'cartService'
        proxyTargetClass = true
    }
}

代理是手动完成的，因此您可以删除 static proxy

class CartService {
    static scope = 'session'
    def items = []

    def getItemCount() {
        items.size()
    }
}

控制器然后引用代理

class CartController {
    def cartServiceProxy 
    ... 
}

请注意一点（至少对我而言）令人困惑的一点是 Controller Documentation for 2.4.x says the default scope is prototype but in the section describing Scoped Services 它表示从 2.3.x 开始默认控制器范围是 singleton.

希望这对您有所帮助。

更新：澄清一下，在 Grails 2.3 之后，默认控制器范围仍然是 prototype，但是当 grails 生成新应用程序时，会生成将默认控制器范围设置为 singleton 的配置（如果可能的话，这真的是你应该拍摄的，就像伯特在下面说的那样）。

在 Config.groovy

中生成配置

// The default scope for controllers. May be prototype, session or singleton.
// If unspecified, controllers are prototype scoped.
grails.controllers.defaultScope = 'singleton'

在 Grails 控制器中包含具有会话范围的服务？

Include Service with Session Scope in Grails Controller?

java

grails

groovy

grails-services