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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2002,2008 Oracle. All rights reserved.
*
* $Id: ScalaPersonExample.scala,v 1.2 2008/01/07 14:28:43 cwl Exp $
*/
import java.io.File
import com.sleepycat.je.{Environment, EnvironmentConfig}
import com.sleepycat.persist.{EntityCursor,EntityStore,StoreConfig}
import com.sleepycat.persist.model.{Entity,PrimaryKey,SecondaryKey}
import com.sleepycat.persist.model.Relationship.ONE_TO_ONE
/**
* Simple example of using Berkeley DB Java Edition (JE) with Scala. The JE
* Direct Persistence Layer (DPL) is used in this example, which requires Java
* 1.5, so the scalac -target:jvm-1.5 option is required when compiling. The
* -Ygenerics option must also be used because DPL generics are used in this
* example.
*
* scalac -Ygenerics -target:jvm-1.5 -cp je-x.y.z.jar ScalaPersonExample.scala
*
* To run the example:
*
* mkdir ./tmp
* scala -cp ".;je-x.y.z.jar" ScalaPersonExample
*
* Note that classOf[java.lang.String] and classOf[java.lang.Long] are used
* rather than classOf[String] and classOf[Long]. The latter use the Scala
* types rather than the Java types and cause run-time errors.
*
* This example was tested with Scala 2.6.1-RC1 and JE 3.2.30.
*
* See:
* http://www.scala-lang.org/
* http://www.oracle.com/technology/products/berkeley-db/je
*/
object ScalaPersonExample extends Application {
/**
* A persistent Entity is defined using DPL annotations.
*/
@Entity
class Person(nameParam: String, addressParam: String) {
@PrimaryKey{val sequence="ID"}
var id: long = 0
@SecondaryKey{val relate=ONE_TO_ONE}
var name: String = nameParam
var address: String = addressParam
private def this() = this(null, null) // default ctor for unmarshalling
override def toString = "Person: " + id + ' ' + name + ' ' + address
}
/* Open the JE Environment. */
val envConfig = new EnvironmentConfig()
envConfig.setAllowCreate(true)
envConfig.setTransactional(true)
val env = new Environment(new File("./tmp"), envConfig)
/* Open the DPL Store. */
val storeConfig = new StoreConfig()
storeConfig.setAllowCreate(true)
storeConfig.setTransactional(true)
val store = new EntityStore(env, "ScalaPersonExample", storeConfig)
/* The PrimaryIndex maps the Long primary key to Person. */
val priIndex =
store.getPrimaryIndex(classOf[java.lang.Long], classOf[Person])
/* The SecondaryIndex maps the String secondary key to Person. */
val secIndex =
store.getSecondaryIndex(priIndex, classOf[java.lang.String], "name")
/* Insert some entities if the primary index is empty. */
val txn = env.beginTransaction(null, null)
if (priIndex.get(txn, 1L, null) == null) {
val person1 = new Person("Zola", "#1 Zola Street")
val person2 = new Person("Abby", "#1 Abby Street")
priIndex.put(txn, person1)
priIndex.put(txn, person2)
assert(person1.id == 1) // assigned from the ID sequence
assert(person2.id == 2) // assigned from the ID sequence
txn.commit()
println("--- Entities were inserted ---")
} else {
txn.abort()
println("--- Entities already exist ---")
}
/* Get entities by primary and secondary keys. */
println("--- Get by primary key ---")
println(priIndex.get(1L))
println(priIndex.get(2L))
assert(priIndex.get(3L) == null)
println("--- Get by secondary key ---")
println(secIndex.get("Zola"))
println(secIndex.get("Abby"))
assert(secIndex.get("xxx") == null)
/* Iterate entities in primary and secondary key order. */
def printAll[T](cursor: EntityCursor[T]) {
val person = cursor.next()
if (person == null) {
cursor.close()
} else {
println(person)
printAll(cursor) // tail recursion
}
}
println("--- Iterate by primary key ---")
printAll(priIndex.entities())
println("--- Iterate by secondary key ---")
printAll(secIndex.entities())
store.close()
env.close()
}
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