GraphCollectionsFactory.fromTransaction() null pointer exception

[klaudworks]

I tried to create a graph collection from graph transactions and received a null pointer exception.

  @Test
  public void testWrite() throws Exception {
    FlinkAsciiGraphLoader testLoader = getSocialNetworkLoader();
    GraphCollection testCollection = testLoader.getGraphCollectionByVariables("g0","g1","g2","g3");

    GraphCollectionFactory graphCollectionFactory = new GraphCollectionFactory(getConfig());
    graphCollectionFactory.fromTransactions(testCollection.getGraphTransactions()); // null pointer exception is thrown here
  }

Error:

java.lang.NullPointerException
	at org.gradoop.flink.model.api.epgm.GraphCollectionFactory.fromTransactions(GraphCollectionFactory.java:120)
	at org.gradoop.flink.io.impl.gdl.GDLDataSinkTest.testWrite(GDLDataSinkTest.java:21)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
	at org.junit.rules.RunRules.evaluate(RunRules.java:20)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

testCollection.getGraphTransactions is not null

[timo95]

layoutFactory is null. You first have to set a layout factory with graphCollectionFactory.setLayoutFactory().

[p-f]

Use

GraphCollectionFactory graphCollectionFactory = getConfig().getGraphCollectionFactory()

instead, that way the layout factories will be set correctly.