should BXCollection.listResources always throw an exception? - BaseX-Talk - mailman.uni-konstanz.de

14 Apr 2011


      Dear BaseXers,
So far, BaseX has been a lot of fun to work with! Thanks for all your
efforts on this codebase.
i've got a couple of questions, though.
- Whether i've got no documents in a freshly created BXCollection, or
   i've ensured that there is at least one document present, a call to
   listResources always throws an IndexOutOfBounds exception. Is that the
   intended behavior?
   - The reason i'm using this API is that i need to be able to update a
   single document in a collection guaranteed to have exactly one document. So,
   i thought i would simply ask the BXCollection to list it's resources, grab
   the first one (since there should only be one) and then use the id from the
   list returned by that API in subsequent queries. Maybe that's not the
   preferred approach? Is there a better one?
Any help would be greatly appreciated.
Best wishes,
--greg
override def getCollection( createIfMissing : Boolean )(
    xmlCollStr : String
  ) : Option[Collection] = {
    try {
      // BUGBUG -- LGM the semantics of BXCollection a little
      // different than createIfMissing; and requires catching the
      // database not found exception
      Some( new BXCollection( xmlCollStr, true ) )
    }
    catch {
      case e : XMLDBException => {
val bxColl = new BXCollection( xmlCollStr, false )
val document =
  bxColl.createResource(
    null, XMLResource.RESOURCE_TYPE
  ).asInstanceOf[XMLResource]
document.setContent( "<database></database>" )
bxColl.storeResource( document )
Some( bxColl )
      }
      case _ => None
    }
  }
override def update( xmlCollStr : String )(
    cnxn : CnxnCtxtLabel[Namespace,Var,String]
  ) : Unit = {
    for( xmlColl <- getCollection( true )( xmlCollStr ) ) {
      val resourceList : Array[String] = xmlColl.listResources
      if ( resourceList.size == 0 ) {
val document =
  xmlColl.createResource(
    null, XMLResource.RESOURCE_TYPE
  ).asInstanceOf[XMLResource]
document.setContent( xmlIfier.asXML( cnxn ).toString )
xmlColl.storeResource( document )
      }
      else {
val cnxnElem = xmlIfier.asXML( cnxn )
cnxnElem match {
  case cElem : Elem => {
    delete( xmlCollStr, resourceList( 0 ) )( cElem )
    insert( xmlCollStr, resourceList( 0 ) )( cElem )
  }
  case _ => {
    throw new Exception( "record is not an XML element" )
  }
}
      }
    }
  }
<tweet>storing to db : org.basex.api.xmldb.BXDatabase@77dc754 pair :
record(contactMeUsing(email),
{&quot;com.biosimilarity.lift.model.store.MonadicTermTypes_-Ground&quot;:{&quot;v&quot;:{&quot;@class&quot;:&quot;string&quot;,&quot;$&quot;:&quot;for
the win Mikail.Mauz@gmail.com&quot;},&quot;_-outer&quot;:{&quot;@class&quot;:&quot;com.biosimilarity.lift.model.store.PersistedMonadicTS$TheMTT$&quot;}}})
in coll : Squibble</tweet>
java.lang.IndexOutOfBoundsException
at java.io.RandomAccessFile.readBytes(Native Method)
at java.io.RandomAccessFile.read(RandomAccessFile.java:322)
at java.io.RandomAccessFile.readFully(RandomAccessFile.java:381)
at org.basex.io.DataAccess.cursor(DataAccess.java:225)
at org.basex.io.DataAccess.readToken(DataAccess.java:147)
at org.basex.data.DiskData.txt(DiskData.java:213)
at org.basex.data.DiskData.text(DiskData.java:181)
at org.basex.api.xmldb.BXCollection.listResources(BXCollection.java:128)
at
com.biosimilarity.lift.model.store.xml.BaseXCnxnStorage$$anonfun$update$1.apply(BaseXXMLPersist.scala:313)
at
com.biosimilarity.lift.model.store.xml.BaseXCnxnStorage$$anonfun$update$1.apply(BaseXXMLPersist.scala:312)
at scala.Option.foreach(Option.scala:185)
at
com.biosimilarity.lift.model.store.xml.BaseXCnxnStorage$class.update(BaseXXMLPersist.scala:312)
at
com.biosimilarity.lift.model.store.PersistedTermStoreScope$PersistedMonadicGeneratorJunction.update(PersistedMonadicTermStore.scala:321)
at
com.biosimilarity.lift.model.store.PersistedTermStoreScope$PersistedMonadicGeneratorJunction$$anonfun$putInStore$3$$anonfun$apply$12$$anonfun$apply$13.apply(PersistedMonadicTermStore.scala:468)
at
com.biosimilarity.lift.model.store.PersistedTermStoreScope$PersistedMonadicGeneratorJunction$$anonfun$putInStore$3$$anonfun$apply$12$$anonfun$apply$13.apply(PersistedMonadicTermStore.scala:459)
at scala.Option.foreach(Option.scala:185)
at
com.biosimilarity.lift.model.store.PersistedTermStoreScope$PersistedMonadicGeneratorJunction$$anonfun$putInStore$3$$anonfun$apply$12.apply(PersistedMonadicTermStore.scala:459)
at
com.biosimilarity.lift.model.store.PersistedTermStoreScope$PersistedMonadicGeneratorJunction$$anonfun$putInStore$3$$anonfun$apply$12.apply(PersistedMonadicTermStore.scala:458)
at scala.Option.foreach(Option.scala:185)
at
com.biosimilarity.lift.model.store.PersistedTermStoreScope$PersistedMonadicGeneratorJunction$$anonfun$putInStore$3.apply(PersistedMonadicTermStore.scala:458)
at
com.biosimilarity.lift.model.store.PersistedTermStoreScope$PersistedMonadicGeneratorJunction$$anonfun$putInStore$3.apply(PersistedMonadicTermStore.scala:458)
at scala.util.continuations.package$.run(package.scala:30)
at scala.concurrent.cpsops$$anonfun$spawn$1.apply$mcV$sp(cpsops.scala:9)
at
scala.concurrent.FJTaskRunners$FJTaskRunner$$anon$1.compute(FJTaskRunners.scala:21)
at jsr166y.forkjoin.RecursiveAction.exec(RecursiveAction.java:247)
at jsr166y.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:286)
-- 
L.G. Meredith
Managing Partner
Biosimilarity LLC
7329 39th Ave SW
Seattle, WA 98136

+1 206.650.3740

http://biosimilarity.blogspot.com