Grails在Service类中获得Session和Management [英] Grails get Session and Management in Service class

问题描述

我在Grails Session上遇到问题.我当时正在考虑为会话处理设置一个服务类.因此，我创建了一个名为"SessionService"的类(位于grails-app/services/grails/下).

I have a problem with Grails Session. I was thinking about having a Service Class for my session handling. So I created a class called "SessionService" (under grails-app/services/grails/).

class SessionService {
    static transactional = true
    GrailsWebRequest request = RequestContextHolder.currentRequestAttributes()
    GrailsHttpSession session = request.session

    def setTestvar(String value) {
        if (session != null)
            session.setAttribute("sTeststring", value)
    }

    def getTestvar() {
        if (session != null)
            session.getAttribute("sTeststring")
    }
}

现在的问题是，我得到一个Nullpointer-Exception:"方法抛出了'java.lang.NullPointerException'异常.无法评估org.codehaus.groovy.grails.web.servlet.mvc.GrailsHttpSession.ToString ()".

The Problem is now, that I get a Nullpointer-Exception: "Method threw 'java.lang.NullPointerException' exception. Cannot evaluate org.codehaus.groovy.grails.web.servlet.mvc.GrailsHttpSession.ToString()".

我的服务等级的使用，例如在控制器中:

Usage of my Service Class e.g. in a Controller:

class SampleController {

    SessionService sessionService

    def selectAnything = {

        sessionService.setTestvar("test-value")
        render(view: "testview")
    }
}

我在这里做错了什么?这是正确的方法吗?还是我必须在每种方法中都设置"session = request.session"?

What am I'm doing wrong here? Is it the right way? Or do I have to set "session = request.session" in every method?

希望从您那里获得帮助.

Hope to get help from you.

非常感谢您.

干杯

马可

推荐答案

RequestContextHolder来自何处?在grails 3.3.8中(至少在插件中)不可见

where does RequestContextHolder come from? Its not visible in grails 3.3.8 (in plugin at least)

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