Fixed copy paste error that caused class cast exception.

smart-connector/src/main/java/eu/knowledge/engine/smartconnector/impl/ReasonerProcessor.java

@@ -292,9 +292,10 @@ private void continueReasoningForward(eu.knowledge.engine.reasoner.api.BindingSe
 			LOG.debug("All post tasks finished.");
 			if (isComplete) {
 				eu.knowledge.engine.reasoner.api.BindingSet resultBS = new eu.knowledge.engine.reasoner.api.BindingSet();
-				if (aBindingSetHandler != null) {
+				if (aBindingSetHandler != null && aBindingSetHandler.getBindingSet() != null) {
 					resultBS = aBindingSetHandler.getBindingSet();
 				}
+
 				this.finalBindingSetFuture.complete(resultBS);
 			} else {
 				continueReasoningForward(incomingBS, aBindingSetHandler);
@@ -365,7 +366,7 @@ public CompletableFuture<Void> handle(eu.knowledge.engine.reasoner.api.BindingSe
 			future.handle((r, e) -> {
 
 				if (e != null) {
-					LOG.error("An exception has occured while capturing binging set", e);
+					LOG.error("An exception has occured while capturing binding set", e);
 					return null;
 				} else {
 					return r;
@@ -491,7 +492,7 @@ private <T extends KnowledgeMessage, S extends KnowledgeMessage> S createFailedR
 					incomingMessage.getFromKnowledgeInteraction(), incomingMessage.getMessageId(), failedMessage);
 
 		} else if (incomingMessage instanceof PostMessage) {
-			outgoingMessage = (S) new AnswerMessage(incomingMessage.getToKnowledgeBase(),
+			outgoingMessage = (S) new ReactMessage(incomingMessage.getToKnowledgeBase(),
 					incomingMessage.getToKnowledgeInteraction(), incomingMessage.getFromKnowledgeBase(),
 					incomingMessage.getFromKnowledgeInteraction(), incomingMessage.getMessageId(), failedMessage);
 		}
@@ -604,12 +605,20 @@ public CompletableFuture<Void> handle(eu.knowledge.engine.reasoner.api.BindingSe
 						.sendPostMessage(postMessage);
 				Instant aPreviousSend = Instant.now();
 				bsFuture = sendPostMessage.exceptionally((Throwable t) -> {
-					LOG.error("A problem occurred while handling a bindingset.", t);
-					return null; // TODO when some error happens, what do we return?
+					String failedMessage = MessageFormatter
+							.basicArrayFormat("Error '{}' occurred while waiting for response to message: {}",
+									new String[] {
+											t.getMessage() != null ? t.getMessage() : t.getClass().getSimpleName(),
+											postMessage.getMessageId().toString() });
+					LOG.warn(failedMessage);
+					LOG.debug("", t);
+					return ReasonerProcessor.this
+							.<PostMessage, ReactMessage>createFailedResponseMessageFromRequestMessage(postMessage,
+									failedMessage);
 				}).thenApply((reactMessage) -> {
-
-					ReasonerProcessor.this.postExchangeInfos
-							.add(convertMessageToExchangeInfo(newBS, new BindingSet(), reactMessage, aPreviousSend));
+					assert reactMessage != null;
+					ReasonerProcessor.this.postExchangeInfos.add(
+							convertMessageToExchangeInfo(newBS, reactMessage.getResult(), reactMessage, aPreviousSend));
 
 					return (Void) null;
 				});

smart-connector/src/test/java/eu/knowledge/engine/smartconnector/api/TestPostReact4.java

@@ -0,0 +1,115 @@
+package eu.knowledge.engine.smartconnector.api;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import java.util.Iterator;
+import java.util.concurrent.ExecutionException;
+
+import org.apache.jena.shared.PrefixMapping;
+import org.apache.jena.sparql.graph.PrefixMappingMem;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import eu.knowledge.engine.smartconnector.util.KnowledgeNetwork;
+import eu.knowledge.engine.smartconnector.util.KnowledgeBaseImpl;
+
+public class TestPostReact4 {
+	private static KnowledgeBaseImpl kb1;
+	private static KnowledgeBaseImpl kb2;
+
+	public boolean kb2Received = false;
+
+	private static final Logger LOG = LoggerFactory.getLogger(TestPostReact4.class);
+
+	@Test
+	public void testPostReactTimeout() throws InterruptedException {
+		System.setProperty(SmartConnectorConfig.CONF_KEY_KE_KB_WAIT_TIMEOUT, "1");
+		PrefixMappingMem prefixes = new PrefixMappingMem();
+		prefixes.setNsPrefixes(PrefixMapping.Standard);
+		prefixes.setNsPrefix("ex", "https://www.tno.nl/example/");
+
+		KnowledgeNetwork kn = new KnowledgeNetwork();
+		kb1 = new KnowledgeBaseImpl("kb1");
+		kn.addKB(kb1);
+		kb2 = new KnowledgeBaseImpl("kb2");
+		kn.addKB(kb2);
+
+		GraphPattern gp1 = new GraphPattern(prefixes, "?a <https://www.tno.nl/example/b> ?c.");
+		PostKnowledgeInteraction pKI = new PostKnowledgeInteraction(new CommunicativeAct(), gp1, null);
+		kb1.register(pKI);
+
+		GraphPattern gp2 = new GraphPattern(prefixes, "?d <https://www.tno.nl/example/b> ?e.");
+		ReactKnowledgeInteraction rKI = new ReactKnowledgeInteraction(new CommunicativeAct(), gp2, null);
+		kb2.register(rKI, ((anRKI, aReactExchangeInfo) -> {
+			LOG.trace("KB2 reacting...");
+			TestPostReact4.this.kb2Received = true;
+			var argument = aReactExchangeInfo.getArgumentBindings();
+			Iterator<Binding> iter = argument.iterator();
+			assertTrue(iter.hasNext(), "There should be at least a single binding.");
+			Binding b = iter.next();
+
+			assertEquals("<https://www.tno.nl/example/a>", b.get("d"), "Binding of 'd' is incorrect.");
+			assertEquals("<https://www.tno.nl/example/c>", b.get("e"), "Binding of 'e' is incorrect.");
+
+			assertFalse(iter.hasNext(), "This BindingSet should only have a single binding.");
+
+			try {
+				Thread.sleep(2000);
+			} catch (InterruptedException e) {
+				LOG.error("{}", e);
+			}
+
+			return new BindingSet();
+		}));
+
+		kn.sync();
+		LOG.info("Everyone is up-to-date!");
+
+		BindingSet bindingSet = new BindingSet();
+		Binding binding = new Binding();
+		binding.put("a", "<https://www.tno.nl/example/a>");
+		binding.put("c", "<https://www.tno.nl/example/c>");
+		bindingSet.add(binding);
+
+		try {
+			PostResult result = kb1.post(pKI, bindingSet).get();
+
+			assertTrue(this.kb2Received, "KB2 should have received the posted data.");
+
+			assertEquals(result.getExchangeInfoPerKnowledgeBase().iterator().next().getStatus(),
+					ExchangeInfo.Status.FAILED);
+
+			BindingSet bs = result.getBindings();
+			assertTrue(bs.isEmpty());
+
+			LOG.info("After post!");
+		} catch (ExecutionException e) {
+			LOG.error("Error", e);
+			fail();
+		}
+	}
+
+	@AfterAll
+	public static void cleanup() {
+		System.clearProperty(SmartConnectorConfig.CONF_KEY_KE_KB_WAIT_TIMEOUT);
+		LOG.info("Clean up: {}", TestPostReact4.class.getSimpleName());
+		if (kb1 != null) {
+			kb1.stop();
+		} else {
+			fail("KB1 should not be null!");
+		}
+
+		if (kb2 != null) {
+
+			kb2.stop();
+		} else {
+			fail("KB2 should not be null!");
+		}
+	}
+
+}

smart-connector/src/test/java/eu/knowledge/engine/smartconnector/api/TestPostReact5.java

@@ -0,0 +1,123 @@
+package eu.knowledge.engine.smartconnector.api;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import java.util.Iterator;
+import java.util.concurrent.ExecutionException;
+
+import org.apache.jena.shared.PrefixMapping;
+import org.apache.jena.sparql.graph.PrefixMappingMem;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import eu.knowledge.engine.smartconnector.util.KnowledgeNetwork;
+import eu.knowledge.engine.smartconnector.util.KnowledgeBaseImpl;
+
+public class TestPostReact5 {
+	private static KnowledgeBaseImpl kb1;
+	private static KnowledgeBaseImpl kb2;
+
+	public boolean kb2Received = false;
+
+	private static final Logger LOG = LoggerFactory.getLogger(TestPostReact5.class);
+
+	@Test
+	public void testPostReactTimeout() throws InterruptedException {
+		System.setProperty(SmartConnectorConfig.CONF_KEY_KE_KB_WAIT_TIMEOUT, "1");
+		PrefixMappingMem prefixes = new PrefixMappingMem();
+		prefixes.setNsPrefixes(PrefixMapping.Standard);
+		prefixes.setNsPrefix("ex", "https://www.tno.nl/example/");
+
+		KnowledgeNetwork kn = new KnowledgeNetwork();
+		kb1 = new KnowledgeBaseImpl("kb1");
+		kn.addKB(kb1);
+		kb2 = new KnowledgeBaseImpl("kb2");
+		kn.addKB(kb2);
+
+		GraphPattern gp1 = new GraphPattern(prefixes, "?a <https://www.tno.nl/example/b> ?c.");
+		GraphPattern gp2 = new GraphPattern(prefixes, "?a <https://www.tno.nl/example/d> ?c.");
+		PostKnowledgeInteraction pKI = new PostKnowledgeInteraction(new CommunicativeAct(), gp1, gp2);
+		kb1.register(pKI);
+
+		GraphPattern gp3 = new GraphPattern(prefixes, "?d <https://www.tno.nl/example/b> ?e.");
+		GraphPattern gp4 = new GraphPattern(prefixes, "?d <https://www.tno.nl/example/d> ?e.");
+		ReactKnowledgeInteraction rKI = new ReactKnowledgeInteraction(new CommunicativeAct(), gp3, gp4);
+		kb2.register(rKI, ((anRKI, aReactExchangeInfo) -> {
+			LOG.trace("KB2 reacting...");
+			TestPostReact5.this.kb2Received = true;
+			var argument = aReactExchangeInfo.getArgumentBindings();
+			Iterator<Binding> iter = argument.iterator();
+			assertTrue(iter.hasNext(), "There should be at least a single binding.");
+			Binding b = iter.next();
+
+			assertEquals("<https://www.tno.nl/example/a>", b.get("d"), "Binding of 'd' is incorrect.");
+			assertEquals("<https://www.tno.nl/example/c>", b.get("e"), "Binding of 'e' is incorrect.");
+
+			assertFalse(iter.hasNext(), "This BindingSet should only have a single binding.");
+
+			try {
+				Thread.sleep(2000);
+			} catch (InterruptedException e) {
+				LOG.error("{}", e);
+			}
+
+			BindingSet bindingSet = new BindingSet();
+			Binding bind = new Binding();
+			bind.put("d", b.get("d"));
+			bind.put("e", b.get("e"));
+			bindingSet.add(bind);
+
+			return bindingSet;
+		}));
+
+		kn.sync();
+		LOG.info("Everyone is up-to-date!");
+
+		BindingSet bindingSet = new BindingSet();
+		Binding binding = new Binding();
+		binding.put("a", "<https://www.tno.nl/example/a>");
+		binding.put("c", "<https://www.tno.nl/example/c>");
+		bindingSet.add(binding);
+
+		try {
+			PostResult result = kb1.post(pKI, bindingSet).get();
+
+			assertTrue(this.kb2Received, "KB2 should have received the posted data.");
+
+			assertEquals(result.getExchangeInfoPerKnowledgeBase().iterator().next().getStatus(),
+					ExchangeInfo.Status.FAILED);
+
+			BindingSet bs = result.getBindings();
+			assertTrue(bs.isEmpty());
+
+			LOG.info("After post!");
+		} catch (ExecutionException e) {
+			LOG.error("Error", e);
+			fail();
+		}
+	}
+
+	@AfterAll
+	public static void cleanup() {
+		System.clearProperty(SmartConnectorConfig.CONF_KEY_KE_KB_WAIT_TIMEOUT);
+		LOG.info("Clean up: {}", TestPostReact5.class.getSimpleName());
+		if (kb1 != null) {
+			kb1.stop();
+		} else {
+			fail("KB1 should not be null!");
+		}
+
+		if (kb2 != null) {
+
+			kb2.stop();
+		} else {
+			fail("KB2 should not be null!");
+		}
+	}
+
+}