Slight refactor for core methods

Author: vkalapov

multiapps-mta/src/main/java/org/cloudfoundry/multiapps/mta/resolvers/ParameterChecker.java

@@ -1,7 +1,5 @@
 package org.cloudfoundry.multiapps.mta.resolvers;
 
-import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
@@ -32,10 +30,9 @@ public abstract class ParameterChecker extends Visitor implements SimpleProperty
 
     protected abstract Set<String> getDependencyParametersToMatch();
 
-    public List<String> checkMatches(DeploymentDescriptor descriptor, List<String> container) {
+    public void fillListWithUnmatched(DeploymentDescriptor descriptor, List<String> container) {
         this.matchedParameters = container;
         descriptor.accept(this);
-        return matchedParameters != null ? matchedParameters : Collections.emptyList();
     }
 
     @Override
@@ -91,14 +88,8 @@ public Object visit(String key, String value) {
 
     private void parameterKeyMatches(String valueToMatch) {
         if (currentParameters != null && !currentParameters.contains(valueToMatch)) {
-            addMatchedParameter(valueToMatch);
+            matchedParameters.add(valueToMatch);
         }
     }
 
-    private void addMatchedParameter(String parameter) {
-        if (matchedParameters == null) {
-            matchedParameters = new ArrayList<>();
-        }
-        matchedParameters.add(parameter);
-    }
 }

multiapps-mta/src/main/java/org/cloudfoundry/multiapps/mta/resolvers/ReferencesFinder.java

@@ -1,8 +1,6 @@
 package org.cloudfoundry.multiapps.mta.resolvers;
 
-import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 import java.util.regex.Matcher;
@@ -26,9 +24,9 @@ public class ReferencesFinder extends Visitor implements SimplePropertyVisitor {
 
     private Set<String> foundReferences;
 
-    public Set<String> findReferences(DeploymentDescriptor descriptor) {
+    public void fillWithReferences(DeploymentDescriptor descriptor, Set<String> referenceContainer) {
+        this.foundReferences = referenceContainer;
         descriptor.accept(this);
-        return foundReferences != null ? foundReferences : Collections.emptySet();
     }
 
     @Override
@@ -90,17 +88,10 @@ private void referencePatternMatches(String valueToMatch) {
             while (matcher.find()) {
                 for (int i = 1; i <= matcher.groupCount(); i++) {
                     String reference = matcher.group(i);
-                    addReference(reference);
+                    foundReferences.add(reference);
                 }
             }
         }
     }
 
-    private void addReference(String reference) {
-        if (foundReferences == null) {
-            foundReferences = new HashSet<>();
-        }
-        foundReferences.add(reference);
-    }
-
 }

multiapps-mta/src/test/java/org/cloudfoundry/multiapps/mta/resolvers/ParameterCheckerTest.java

@@ -39,8 +39,8 @@ void testGetMatches(String descriptorLocation, List<String> expectedResult) {
         ParameterChecker parameterChecker = new ParameterCheckerTestImpl();
         DeploymentDescriptor descriptor = parseDeploymentDescriptor(descriptorLocation);
         List<String> container = new ArrayList<>();
-        List<String> actualMatches = parameterChecker.checkMatches(descriptor, container);
-        assertEquals(expectedResult, actualMatches);
+        parameterChecker.fillListWithUnmatched(descriptor, container);
+        assertEquals(expectedResult, container);
     }
 
     private DeploymentDescriptor parseDeploymentDescriptor(String deploymentDescriptorLocation) {

multiapps-mta/src/test/java/org/cloudfoundry/multiapps/mta/resolvers/ReferencesFinderTest.java

@@ -1,6 +1,7 @@
 package org.cloudfoundry.multiapps.mta.resolvers;
 
 import java.io.InputStream;
+import java.util.HashSet;
 import java.util.Set;
 import java.util.stream.Stream;
 
@@ -32,8 +33,9 @@ static Stream<Arguments> testGetReferences() {
     @MethodSource
     void testGetReferences(String descriptorLocation, Set<String> expectedResult) {
         ReferencesFinder finder = new ReferencesFinder();
+        Set<String> actualReferences = new HashSet<>();
         DeploymentDescriptor descriptor = parseDeploymentDescriptor(descriptorLocation);
-        Set<String> actualReferences = finder.findReferences(descriptor);
+        finder.fillWithReferences(descriptor, actualReferences);
         assertEquals(expectedResult, actualReferences);
     }