grails thread-> hibernateException：没有绑定到线程的Hibernate会话

Question

I'm trying to create some threads in a service, but I got the hibernateException: no session... . I have already seen a discussion about this in stackoverflow with a solution of throwing RuntimeException. In my case is not working. Here is my service code:

class MatchService {

    static transactional = true

 def void start(Match match) {

  Thread.start {
   Match updateMatch = matchSituation(match)
   if(!updateMatch.save()) {
    throw new RuntimeException("match is not valid and cannot be saved!")
   }
  }
 }

 def Match matchSituation(Match m) {
  Random random = new Random()
  if(m.teamH.averagePlayerValue > m.teamA.averagePlayerValue) {
   m.golTeamH = random.nextInt(5)
  }
  else {
   m.golTeamA = random.nextInt(4)
  }
  return m
 }
}

job class:

 class TestJob {

     def matchService
     List<Match> matchList = new ArrayList()

     static triggers = {
      cron name: 'trigger',  cronExpression: "0 0/1 15 ? * WED"
      }

     def group = "threadGroup"


        def execute() {
      Cal.get(1).matches.each{
       match ->
        matchList.add(match)
      }

      for(Match m: matchList) {
       if(!m.validate()) {
        throw new MatchException( message: "match not valid!!" , match:m)
       }
       matchService.start(m)

      }
        }
    }

EDIT

With backgroundThread plugin (that should handle hibernate sessione):

    backgroundService.execute("Calculating match", {
        def backgroundMatch = match
        backgroundMatch = matchSituation(backgroundMatch)
        if(!backgroundMatch.save()) {
            throw new RuntimeException("match is not valid and cannot be saved!")
        }
    })

I get this error ERROR events.PatchedDefaultFlushEventListener - Could not synchronize database state with session

Answer 1

We're using the quartz plugin which works fine.

I have had the same problem before in a different case and what solved it was wrapping the domain access code in

DomainClass.withTransaction {
}

For example:

def execute() {
  Cal.withTransaction {
    Cal.get(1).matches.each{
        match ->
        matchList.add(match)
    }

    for(Match m: matchList) {
        if(!m.validate()) {
            throw new MatchException( message: "match not valid!!" , match:m)
        }
        matchService.start(m)

    }
  }
}

Answer 2

通过将Domain-class中的fetchmode设置为eager，可以修复来自Hibernate的懒惰异常。

Answer 3

I think your problem is in passing the actual domain object to the thread. Try just passing the domain object ID to the function, and obtaining and saving inside that function/thread. Passing a domain object to another thread can cause problems.

Answer 4

now is working. Here are the changes I made:

class TestJob {

    def matchService
    List<Match> matchList = new ArrayList()

    static triggers = {
        cron name: 'trigger',  cronExpression: "0 0/1 13 ? * THU"
    }

    def group = "threadGroup"


    def execute() {
        Cal.get(1).matches.each{ match ->
            matchList.add(match)
        }

        for(Match m: matchList) {
            if(!m.validate()) {
                throw new MatchException( message: "match not valid!!" , match:m)
            }
            matchService.run(m.id)
        }
    }
}

class MatchService {

    static transactional = true

//  Match updateMatch
    def backgroundService

    public void run(Long matchId) {

        backgroundService.execute("Calculating match", {
            def backgroundMatch = Match.findById(matchId)
            backgroundMatch = matchSituation(backgroundMatch)
            println backgroundMatch.teamH.name + " - " + backgroundMatch.teamA.name + ": " + backgroundMatch.golTeamH + " - " + backgroundMatch.golTeamA
            if(!backgroundMatch.save()) {
                throw new RuntimeException("match is not valid and cannot be saved!")
            }
        })
//      Thread.start {
//          println "run thread (" + matchId + ") : " + String.format('%tH:%<tM:%<tS.%<tL',System.currentTimeMillis())
//          this.updateMatch = matchSituation(Match.findById(matchId))
//          println updateMatch.teamH.name + " - " + updateMatch.teamA.name + ": " + updateMatch.golTeamH + " - " + updateMatch.golTeamA
//          if(!updateMatch.save(flush: true)) {
//              throw new RuntimeException("match is not valid and cannot be saved!")
//          }
//      }
    }

    def Match matchSituation(Match m) {
        Random random = new Random()
        if(m.teamH.averagePlayerValue > m.teamA.averagePlayerValue) {
            m.golTeamH = random.nextInt(5)
        }
        else {
            m.golTeamA = random.nextInt(4)
        }
        return m
    }
}