卡桑德拉单位与斯卡拉。不会话
问题描述:
我想用cassandraunit测试Cassandra。我从github粘贴测试并转换为Scala,但它不起作用。卡桑德拉单位与斯卡拉。不会话
import org.junit.Rule
import org.scalatest.FunSuite
import com.datastax.driver.core.ResultSet
import org.cassandraunit.CassandraCQLUnit
import org.cassandraunit.dataset.cql.ClassPathCQLDataSet
class CassandraTest extends FunSuite{
@Rule
val cassandraCQLUnit = new CassandraCQLUnit(new ClassPathCQLDataSet("statementsWithBlankEndings.cql", "mykeyspace"))
test("really simple transformation") {
val session = cassandraCQLUnit.session
val resultSet = session.execute("select * from testCQLTable WHERE id='1690e8da-5bf8-49e8-9583-4dff8a570737'")
println(resultSet.iterator().next().getString("value"))
}
}
java.lang.NullPointerException was thrown.
java.lang.NullPointerException
at CassandraTest$$anonfun$1.apply$mcV$sp(CassandraTest.scala:21)
at CassandraTest$$anonfun$1.apply(CassandraTest.scala:18)
at CassandraTest$$anonfun$1.apply(CassandraTest.scala:18)
at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.FunSuiteLike$$anon$1.apply(FunSuiteLike.scala:186)
at org.scalatest.TestSuite$class.withFixture(TestSuite.scala:196)
at org.scalatest.FunSuite.withFixture(FunSuite.scala:1560)
at org.scalatest.FunSuiteLike$class.invokeWithFixture$1(FunSuiteLike.scala:183)
at org.scalatest.FunSuiteLike$$anonfun$runTest$1.apply(FunSuiteLike.scala:196)
at org.scalatest.FunSuiteLike$$anonfun$runTest$1.apply(FunSuiteLike.scala:196)
at org.scalatest.SuperEngine.runTestImpl(Engine.scala:289)
at org.scalatest.FunSuiteLike$class.runTest(FunSuiteLike.scala:196)
at org.scalatest.FunSuite.runTest(FunSuite.scala:1560)
at org.scalatest.FunSuiteLike$$anonfun$runTests$1.apply(FunSuiteLike.scala:229)
at org.scalatest.FunSuiteLike$$anonfun$runTests$1.apply(FunSuiteLike.scala:229)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:396)
at org.scalatest.SuperEngine$$anonfun$traverseSubNodes$1$1.apply(Engine.scala:384)
at scala.collection.immutable.List.foreach(List.scala:381)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:384)
at org.scalatest.SuperEngine.org$scalatest$SuperEngine$$runTestsInBranch(Engine.scala:379)
at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:461)
at org.scalatest.FunSuiteLike$class.runTests(FunSuiteLike.scala:229)
at org.scalatest.FunSuite.runTests(FunSuite.scala:1560)
at org.scalatest.Suite$class.run(Suite.scala:1147)
at org.scalatest.FunSuite.org$scalatest$FunSuiteLike$$super$run(FunSuite.scala:1560)
at org.scalatest.FunSuiteLike$$anonfun$run$1.apply(FunSuiteLike.scala:233)
at org.scalatest.FunSuiteLike$$anonfun$run$1.apply(FunSuiteLike.scala:233)
at org.scalatest.SuperEngine.runImpl(Engine.scala:521)
at org.scalatest.FunSuiteLike$class.run(FunSuiteLike.scala:233)
at org.scalatest.FunSuite.run(FunSuite.scala:1560)
at org.scalatest.tools.SuiteRunner.run(SuiteRunner.scala:45)
at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$1.apply(Runner.scala:1340)
at org.scalatest.tools.Runner$$anonfun$doRunRunRunDaDoRunRun$1.apply(Runner.scala:1334)
at scala.collection.immutable.List.foreach(List.scala:381)
at org.scalatest.tools.Runner$.doRunRunRunDaDoRunRun(Runner.scala:1334)
at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1011)
at org.scalatest.tools.Runner$$anonfun$runOptionallyWithPassFailReporter$2.apply(Runner.scala:1010)
at org.scalatest.tools.Runner$.withClassLoaderAndDispatchReporter(Runner.scala:1500)
at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:1010)
at org.scalatest.tools.Runner$.run(Runner.scala:850)
at org.scalatest.tools.Runner.run(Runner.scala)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.runScalaTest2(ScalaTestRunner.java:138)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.main(ScalaTestRunner.java:28)
Session变量为空,我不知道为什么。我了解cassandraCQLUnit在同一个VM中有一个Cassandra服务器。是否有必要做别的事情?
答
您需要启动服务器并连接。然后你可以加载数据:
import com.datastax.driver.core.{Cluster, Session}
import org.cassandraunit.CQLDataLoader
import org.cassandraunit.dataset.cql.ClassPathCQLDataSet
import org.cassandraunit.utils.EmbeddedCassandraServerHelper
import org.scalatest.{BeforeAndAfterAll, FunSuite}
class CassandraTest extends FunSuite
with BeforeAndAfterAll {
var cluster : Cluster = _
var session : Session = _
override def beforeAll(): Unit = {
EmbeddedCassandraServerHelper.startEmbeddedCassandra(EmbeddedCassandraServerHelper.CASSANDRA_RNDPORT_YML_FILE)
cluster = EmbeddedCassandraServerHelper.getCluster()
session = cluster.connect()
val dataLoader = new CQLDataLoader(session)
dataLoader.load(new ClassPathCQLDataSet("statementsWithBlankEndings.cql","mykeyspace"))
}
test("really simple transformation") {
val resultSet = session.execute("select * from mykeyspace.testCQLTable WHERE id='1690e8da-5bf8-49e8-9583-4dff8a570737'")
println(resultSet.iterator().next().getString("value"))
}
}
有一个Cassandra的Scala驱动程序:https://github.com/outworkers/phantom,你不需要键入CQL字符串。 你需要在'session'被初始化之前调用'connect()',所以无论出于什么原因,都不会被调用或失败。 – flavian