grails - 在Grails的TagLib中使用request.getSession(false)会引发异常

Question

我试图在Grails 2.3.5的TagLib中使用以下代码。

class LoginTagLib {
   def loginControl = {
  if(request.getSession(false) && session.user){
    out << "Hello ${session.user.login} "
    out << """[${link(action:"logout",controller:"user"){"Logout"}}]"""
} 
else {
    out << """[${link(action:"login",
    controller:"user"){"Login"}}]"""
}
}

}

我收到以下错误:

groovy.lang.MissingMethodException: No signature of method: org.apache.catalina.connector.RequestFacade.session() is applicable for argument types: (java.lang.Boolean) values: [false]
Possible solutions: getSession(boolean), getSession()
    racetrack.LoginTagLib$_closure1.doCall(LoginTagLib.groovy:9)
    D__JAVA_GRAILS_WORKSPACE_RaceTrack_grails_app_views_layouts__header_gsp.run(_header.gsp:7)
    D__JAVA_GRAILS_WORKSPACE_RaceTrack_grails_app_views_layouts_main_gsp$_run_closure2.doCall(main.gsp:22)
    D__JAVA_GRAILS_WORKSPACE_RaceTrack_grails_app_views_layouts_main_gsp.run(main.gsp:25)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    java.lang.Thread.run(Thread.java:724)

Answer 1

试试这个

def user = session?.user

if (user) {
    out << "Hello ${session.user.login} "
    out << """[${link(action:"logout",controller:"user"){"Logout"}}]"""
}