Question

Using Play! 1.2.4, Scala, and Squeryl with Postgres

Performing a simple DB insert like usual and all of the sudden the database has started throwing NullPointerExceptions like crazy. All started when I created an email invite handler that could auto-add someone to an account.

The code:

Member.scala where the insert takes place:

def insert(member:Member) = DB.members.insert(member)

The code above is where Play! indicates the NullPointerException takes place. When I run the debugger on val member below it shows a valid Member class with appropriate values.

def invitation(s:Option[String]) = {
    s match {
      case Some(s) => {
        val invite = Invite.getByKey(s)

        invite match {
          case Some(invite) => {
            User.search(invite.email) match {
              case Some(user) => {
                  val member = new Member(user.id,invite.accountId,null)
                  Member.insert( member )
                  session.clear()
                  flash += "notice" -> "Success! Please login to continue."
                  Action(Authentication.login)
              }
              case _ => Action(Users.`new`(s))
            }
          }
          case None => Error("Invite does not exist.")
        }
      }
      case None => Action(Application.index)
    }
  }

The stack trace:

Internal Server Error (500) for request GET /invitation?s=e3dfd60e-bc07-496a-918
1-97c6ea4b0b71

Execution exception (In /app/models/Member.scala around line 59)
NullPointerException occured : null

! play.exceptions.JavaExecutionException
!       at play.mvc.ActionInvoker.invoke(ActionInvoker.java:231)
!       at Invocation.HTTP Request(Play!)
! Caused by: java.lang.NullPointerException
!       at org.squeryl.internals.FieldMetaData.get(FieldMetaData.scala:260)
!       at org.squeryl.internals.DatabaseAdapter$class.writeValue(DatabaseAdapte
r.scala:456)
!       at org.squeryl.adapters.PostgreSqlAdapter.writeValue(PostgreSqlAdapter.s
cala:24)
!       at org.squeryl.internals.DatabaseAdapter$$anonfun$writeInsert$2.apply(Da
tabaseAdapter.scala:415)
!       at org.squeryl.internals.DatabaseAdapter$$anonfun$writeInsert$2.apply(Da
tabaseAdapter.scala:415)
!       at org.squeryl.internals.DatabaseAdapter$class.writeInsert(DatabaseAdapt
er.scala:415)
!       at org.squeryl.adapters.PostgreSqlAdapter.writeInsert(PostgreSqlAdapter.
scala:70)
!       at org.squeryl.Table$$anonfun$insert$1.apply(Table.scala:39)
!       at org.squeryl.logging.StackMarker$.lastSquerylStackFrame(StatisticsList
ener.scala:52)
!       at org.squeryl.Table.insert(Table.scala:34)
!       at models.Member$.insert(Member.scala:59)
!       at controllers.Invites$.invitation(Invites.scala:24)
!       at play.mvc.ActionInvoker.invokeWithContinuation(ActionInvoker.java:548)

!       at play.mvc.ActionInvoker.invoke(ActionInvoker.java:502)
!       at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:496)

!       at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:473)

!       at play.mvc.ActionInvoker.invoke(ActionInvoker.java:161)
!       ... 1 more

Help appreciated

Never seen this before and it might be a simple fix, your help is much appreciated.

Answer 1

This one was an easy fix, and I’m a little surprised I didn’t get a hiccup during compile.

When assembling my Member class I used Scala None instead of null on that third value, and it worked just fine.

Too bad Squeryl can’t put out a better error for debugging.