Grails Bean builder for Compass Search on Appengine using JPA

Need to put this down in case i forget

beans = {
    compass(org.compass.spring.LocalCompassBean){
mappingScan = "persisted"
compassSettings = ["compass.engine.connection":"gae://index",
"compass.executorManager.type":"disabled",
"compass.engine.store.gae.cacheMetaData":"true",
"compass.engine.store.gae.flushRate":"50"]
    }

    sameThreadParallelIndexExecutor(org.compass.gps.device.support.parallel.SameThreadParallelIndexExecutor){

    }

    jpaGpsDevice(org.compass.gps.device.jpa.JpaGpsDevice){
name="appengine"
entityManagerFactory = entityManagerFactory
parallelIndexExecutor = sameThreadParallelIndexExecutor
    }
  
    compassGps(org.compass.gps.impl.SingleCompassGps){
compass = compass
gpsDevices = [jpaGpsDevice]
    }
}

JPA query syntax

Within a controller:

def query = entityManager.createQuery("select from Account a where a.key=:key order by ${params.sort} ${params.order}")
query.setParameter("key",session.key)
query.setMaxResults( params.max )
query.setFirstResult( params.offset )
def accounts = query.resultList;

EntityManager isn't injected in Services but jpaTemplate is so:

private getEntityManager(){
jpaTemplate.execute({EntityManager entityManager->
return entityManager;
} as JpaCallback);
}

Beginning Grails on Google AppEngine

Just a quick writeup on Grails+Gorm-JPA+GAE

What you will need:

• http://grails.org/
• http://code.google.com/appengine/
• http://grails.org/plugin/app-engine
• http://grails.org/plugin/gorm-jpa

At the time of this writeup i'm using

• Grails 1.1.1
• GAE 1.2.5
• appengine plugin 0.8.5
• gorm-jpa plugin 0.5

Things to note:

• App engine uses Datanucleus to enhance Domain classes, on Windows there is a character limit on the command line see here one way i found around this problem is to end Domain classes with XXXDomain. e.g. UserDomain.groovy and update %APPENGINE_HOME%/config/user/ant-macros.xml
  from
‹fileset dir="@{war}/WEB-INF/classes" includes="**/*.class"›
  to
‹fileset dir="@{war}/WEB-INF/classes" includes="**/*Domain.class"›
  
• To use google's datatypes in Domains, you have to add the annotation
  @Enumerated
e.g.
@Enumerated
Text longText;
• Also when bootstrapping do NOT populate the FIRST google datatype in a Domain class,
  this causes the datatype NOT to be mapped.
• To simplify saving Text datatypes, you can override the default getters and setters on the Domain class like so:
void setLongText(String text){
longText = new Text(text);
}

String getLongText(){
return longText?.getValue();
}