[KIE-1013] add convenient methods to retrieve objects of a specific c…

…lass from an entry-point (#5789)

drools-alphanetwork-compiler/src/test/java/org/drools/ancompiler/BaseModelTest.java

@@ -37,7 +37,6 @@
 import org.kie.api.builder.Message;
 import org.kie.api.builder.ReleaseId;
 import org.kie.api.builder.model.KieModuleModel;
-import org.kie.api.runtime.ClassObjectFilter;
 import org.kie.api.runtime.KieContainer;
 import org.kie.api.runtime.KieSession;
 import org.kie.internal.builder.conf.AlphaNetworkCompilerOption;
@@ -157,7 +156,7 @@ protected KieModuleModel getDefaultKieModuleModel( KieServices ks ) {
     }
 
     public static <T> List<T> getObjectsIntoList(KieSession ksession, Class<T> clazz) {
-        return (List<T>) ksession.getObjects(new ClassObjectFilter(clazz)).stream().collect(Collectors.toList());
+        return ksession.getInstancesOf(clazz).stream().collect(Collectors.toList());
     }
 
     protected void createAndDeployJar( KieServices ks, ReleaseId releaseId, String... drls ) {

drools-core/src/main/java/org/drools/core/process/ProcessContext.java

@@ -20,7 +20,7 @@
 
 import java.util.Collection;
 
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.kie.api.runtime.KieRuntime;
 import org.kie.api.runtime.process.CaseAssignment;
 import org.kie.api.runtime.process.CaseData;

drools-model/drools-model-codegen/src/test/java/org/drools/model/codegen/execmodel/BaseModelTest.java

@@ -37,16 +37,15 @@
 import org.kie.api.builder.Message;
 import org.kie.api.builder.ReleaseId;
 import org.kie.api.builder.model.KieModuleModel;
-import org.kie.api.runtime.ClassObjectFilter;
 import org.kie.api.runtime.KieContainer;
 import org.kie.api.runtime.KieSession;
 import org.kie.internal.builder.conf.AlphaNetworkCompilerOption;
 
 import static java.util.Arrays.asList;
+import static org.assertj.core.api.Assertions.fail;
 import static org.drools.model.codegen.execmodel.BaseModelTest.RUN_TYPE.PATTERN_DSL;
 import static org.drools.model.codegen.execmodel.BaseModelTest.RUN_TYPE.PATTERN_WITH_ALPHA_NETWORK;
 import static org.drools.model.codegen.execmodel.BaseModelTest.RUN_TYPE.STANDARD_WITH_ALPHA_NETWORK;
-import static org.assertj.core.api.Assertions.fail;
 
 @RunWith(Parameterized.class)
 public abstract class BaseModelTest {
@@ -168,7 +167,7 @@ protected KieModuleModel getDefaultKieModuleModel( KieServices ks ) {
     }
 
     public static <T> List<T> getObjectsIntoList(KieSession ksession, Class<T> clazz) {
-        return (List<T>) ksession.getObjects(new ClassObjectFilter(clazz)).stream().collect(Collectors.toList());
+        return ksession.getInstancesOf(clazz).stream().collect(Collectors.toList());
     }
 
     protected void createAndDeployJar( KieServices ks, ReleaseId releaseId, String... drls ) {

drools-model/drools-model-compiler/src/test/java/org/drools/modelcompiler/PatternDSLTest.java

@@ -376,9 +376,8 @@ public void testQueryInRule() {
 
         ksession.fireAllRules();
 
-        Collection<Result> results = (Collection<Result>) ksession.getObjects( new ClassObjectFilter( Result.class ) );
-        assertThat(results.size()).isEqualTo(1);
-        assertThat(results.iterator().next().getValue()).isEqualTo("Mario");
+        Result result = ksession.getSingleInstanceOf( Result.class );
+        assertThat(result.getValue()).isEqualTo("Mario");
     }
 
     @Test
@@ -1132,6 +1131,6 @@ public void test2AccsWithGetObjectsDeep() throws Exception {
     }
 
     public static <T> List<T> getObjectsIntoList(KieSession ksession, Class<T> clazz) {
-        return (List<T>) ksession.getObjects(new ClassObjectFilter(clazz)).stream().collect(Collectors.toList());
+        return ksession.getInstancesOf(clazz).stream().collect(Collectors.toList());
     }
 }

drools-reliability/drools-reliability-tests/src/test/java/org/drools/reliability/test/ReliabilityTestBasics.java

@@ -26,7 +26,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.kiesession.session.StatefulKnowledgeSessionImpl;
 import org.drools.model.Model;
 import org.drools.model.codegen.ExecutableModelProject;
@@ -431,7 +431,7 @@ protected Optional<Person> getPersonByName(String name) {
     }
 
     protected Optional<Person> getPersonByName(KieSession kieSession, String name) {
-        return kieSession.getObjects(new ClassObjectFilter(Person.class))
+        return kieSession.getInstancesOf( Person.class )
                 .stream()
                 .map(Person.class::cast)
                 .filter(p -> p.getName().equals(name) ).findFirst();

drools-serialization-protobuf/src/test/java/org/drools/serialization/protobuf/TruthMaintenanceTest.java

@@ -18,7 +18,12 @@
  */
 package org.drools.serialization.protobuf;
 
-import org.drools.core.ClassObjectFilter;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
 import org.drools.core.common.EqualityKey;
 import org.drools.core.common.InternalAgenda;
 import org.drools.core.common.InternalFactHandle;
@@ -38,18 +43,13 @@
 import org.kie.api.KieBase;
 import org.kie.api.definition.KiePackage;
 import org.kie.api.io.ResourceType;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.kie.api.runtime.KieSession;
 import org.kie.api.runtime.rule.FactHandle;
 import org.kie.internal.builder.KnowledgeBuilder;
 import org.kie.internal.builder.KnowledgeBuilderFactory;
 import org.kie.internal.io.ResourceFactory;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.fail;
 import static org.drools.serialization.protobuf.SerializationHelper.getSerialisedStatefulKnowledgeSession;

drools-test-coverage/test-compiler-integration/src/test/java/org/drools/compiler/integrationtests/incrementalcompilation/IncrementalCompilationTest.java

@@ -20,7 +20,7 @@
 
 import org.drools.commands.runtime.rule.FireAllRulesCommand;
 import org.drools.compiler.kie.builder.impl.DrlProject;
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.base.definitions.rule.impl.RuleImpl;
 import org.drools.core.event.DefaultAgendaEventListener;
 import org.drools.core.impl.InternalRuleBase;

drools-test-coverage/test-compiler-integration/src/test/java/org/drools/mvel/compiler/beliefsystem/defeasible/DefeasibilityTest.java

@@ -23,7 +23,7 @@
 import java.util.List;
 
 import org.drools.core.BeliefSystemType;
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.core.RuleSessionConfiguration;
 import org.drools.core.common.EqualityKey;
 import org.drools.core.common.InternalFactHandle;

drools-test-coverage/test-compiler-integration/src/test/java/org/drools/mvel/integrationtests/ExpirationTest.java

@@ -25,7 +25,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.core.ClockType;
 import org.drools.core.SessionConfiguration;
 import org.drools.core.impl.RuleBaseFactory;

drools-test-coverage/test-compiler-integration/src/test/java/org/drools/mvel/integrationtests/Misc2Test.java

@@ -46,7 +46,7 @@
 import org.drools.base.base.ValueResolver;
 import org.drools.compiler.builder.impl.KnowledgeBuilderConfigurationImpl;
 import org.drools.compiler.builder.impl.KnowledgeBuilderImpl;
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.base.InitialFact;
 import org.drools.base.base.ClassObjectType;
 import org.drools.core.common.DefaultFactHandle;

drools-test-coverage/test-compiler-integration/src/test/java/org/drools/mvel/integrationtests/session/StatefulSessionTest.java

@@ -23,7 +23,7 @@
 import java.util.Iterator;
 import java.util.List;
 
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.core.common.DefaultFactHandle;
 import org.drools.mvel.compiler.Cheese;
 import org.drools.mvel.compiler.CheeseEqual;

drools-test-coverage/test-integration-nomvel/src/test/java/org/drools/compiler/integrationtests/nomvel/TestUtil.java

@@ -30,7 +30,6 @@
 import org.kie.api.builder.Message;
 import org.kie.api.builder.ReleaseId;
 import org.kie.api.builder.model.KieModuleModel;
-import org.kie.api.runtime.ClassObjectFilter;
 import org.kie.api.runtime.KieContainer;
 import org.kie.api.runtime.KieSession;
 
@@ -99,7 +98,7 @@ public static KieModuleModel getDefaultKieModuleModel( KieServices ks ) {
     }
 
     public static <T> List<T> getObjectsIntoList( KieSession ksession, Class<T> clazz) {
-        return (List<T>) ksession.getObjects(new ClassObjectFilter(clazz)).stream().collect( Collectors.toList());
+        return ksession.getInstancesOf(clazz).stream().collect( Collectors.toList());
     }
 
     public static void createAndDeployJar( KieServices ks, ReleaseId releaseId, String... drls ) {

drools-test-coverage/test-suite/src/test/java/org/drools/testcoverage/regression/FromGenericCollectionTest.java

@@ -18,13 +18,11 @@
  */
 package org.drools.testcoverage.regression;
 
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import org.drools.core.ClassObjectFilter;
 import org.drools.testcoverage.common.util.KieBaseTestConfiguration;
 import org.drools.testcoverage.common.util.KieBaseUtil;
 import org.drools.testcoverage.common.util.TestConstants;
@@ -34,6 +32,7 @@
 import org.junit.runners.Parameterized;
 import org.junit.runners.Parameterized.Parameters;
 import org.kie.api.KieBase;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.kie.api.runtime.KieSession;
 
 import static org.assertj.core.api.Assertions.assertThat;

drools-traits/src/test/java/org/drools/traits/compiler/factmodel/traits/TraitMapCoreTest.java

@@ -24,7 +24,7 @@
 import java.util.Map;
 
 import org.drools.traits.compiler.CommonTraitTest;
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.traits.core.factmodel.TraitableMap;
 import org.drools.traits.core.factmodel.TraitFactoryImpl;
 import org.drools.base.factmodel.traits.Traitable;

drools-verifier/drools-verifier-drl/src/main/java/org/drools/verifier/data/VerifierDataKnowledgeSession.java

@@ -21,7 +21,7 @@
 import java.util.ArrayList;
 import java.util.Collection;
 
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.kiesession.rulebase.InternalKnowledgeBase;
 import org.drools.kiesession.rulebase.KnowledgeBaseFactory;
 import org.drools.verifier.components.EntryPoint;

drools-xml-support/src/test/java/org/drools/xml/support/CommandSerializationTest.java

@@ -38,7 +38,7 @@
 import jakarta.xml.bind.annotation.XmlElement;
 import jakarta.xml.bind.annotation.XmlElements;
 
-import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.ClassObjectFilter;
 import org.drools.core.ClassObjectSerializationFilter;
 import org.drools.core.base.RuleNameEndsWithAgendaFilter;
 import org.drools.core.base.RuleNameEqualsAgendaFilter;

kie-api/src/main/java/org/kie/api/runtime/rule/EntryPoint.java

@@ -19,7 +19,9 @@
 package org.kie.api.runtime.rule;
 
 import java.util.Collection;
+import java.util.NoSuchElementException;
 
+import org.kie.api.runtime.ClassObjectFilter;
 import org.kie.api.runtime.ObjectFilter;
 
 /**
@@ -152,6 +154,34 @@ void update(FactHandle handle,
      */
     Collection<? extends Object> getObjects(ObjectFilter filter);
 
+    /**
+     * Returns a Collection of objects in this entry-point that are instances of the given class.
+     * @param clazz the class of objects to be retrieved
+     * @return all facts from this entry-point that are instance of the given class.
+     */
+    default <T> Collection<T> getInstancesOf(Class<T> clazz) {
+        return (Collection<T>) getObjects(new ClassObjectFilter(clazz));
+    }
+
+    /**
+     * Returns the only object in this entry-point that is an instance of the given class.
+     * @param clazz the class of object to be retrieved
+     * @return the only object from this entry-point that is an instance of the given class.
+     * @throws NoSuchElementException if there isn't any object of the given class in this entry-point
+     * @throws IllegalStateException if there is more than one object of the given class in this entry-point
+     */
+    default <T> T getSingleInstanceOf(Class<T> clazz) {
+        Collection<T> ts = (Collection<T>) getObjects(new ClassObjectFilter(clazz));
+        int size = ts.size();
+        if (size == 0) {
+            throw new NoSuchElementException();
+        }
+        if (size > 1) {
+            throw new IllegalStateException("Found " + size + " instances instead of the expected single one");
+        }
+        return ts.iterator().next();
+    }
+
     /**
      * @return all <code>FactHandle</code>s from the current session.
      */
@@ -168,5 +198,4 @@ void update(FactHandle handle,
      * @return the total number of facts currently in this entry point
      */
     long getFactCount();
-
 }