Review

core/src/main/java/ai/timefold/solver/core/impl/heuristic/selector/move/generic/list/ListChangeMoveSelectorFactory.java

@@ -49,10 +49,10 @@ protected MoveSelector<Solution_> buildBaseMoveSelector(HeuristicConfigPolicy<So
                 .buildValueSelector(configPolicy, entityDescriptor, minimumCacheType, selectionOrder);
 
         if (!(sourceValueSelector instanceof EntityIndependentValueSelector<Solution_> castSourceValueSelector)) {
-            throw new IllegalArgumentException("The listChangeMoveSelector (" + config
-                    + ") for a list variable needs to be based on an "
-                    + EntityIndependentValueSelector.class.getSimpleName() + " (" + sourceValueSelector + ")."
-                    + " Check your valueSelectorConfig.");
+            throw new IllegalArgumentException("""
+                    The listChangeMoveSelector (%s) for a list variable needs to be based on an %s (%s).
+                    Check your valueSelectorConfig."""
+                    .formatted(config, EntityIndependentValueSelector.class.getSimpleName(), sourceValueSelector));
         }
 
         var destinationSelector = DestinationSelectorFactory
@@ -74,9 +74,10 @@ protected MoveSelectorConfig<?> buildUnfoldedMoveSelectorConfig(HeuristicConfigP
                 onlyEntityDescriptor == null ? configPolicy.getSolutionDescriptor().getGenuineEntityDescriptors()
                         : Collections.singletonList(onlyEntityDescriptor);
         if (entityDescriptors.size() > 1) {
-            throw new IllegalArgumentException("The listChangeMoveSelector (" + config
-                    + ") cannot unfold when there are multiple entities (" + entityDescriptors + ")."
-                    + " Please use one listChangeMoveSelector per each planning list variable.");
+            throw new IllegalArgumentException("""
+                    The listChangeMoveSelector (%s) cannot unfold when there are multiple entities (%s).
+                    Please use one listChangeMoveSelector per each planning list variable."""
+                    .formatted(config, entityDescriptors));
         }
         var entityDescriptor = entityDescriptors.iterator().next();
 
@@ -93,24 +94,22 @@ protected MoveSelectorConfig<?> buildUnfoldedMoveSelectorConfig(HeuristicConfigP
                                 .extractVariableDescriptor(configPolicy, entityDescriptor);
         if (onlyVariableDescriptor != null && onlyDestinationVariableDescriptor != null) {
             if (!onlyVariableDescriptor.isListVariable()) {
-                throw new IllegalArgumentException("The listChangeMoveSelector (" + config
-                        + ") is configured to use a planning variable (" + onlyVariableDescriptor
-                        + "), which is not a planning list variable."
-                        + " Either fix your annotations and use a @" + PlanningListVariable.class.getSimpleName()
-                        + " on the variable to make it work with listChangeMoveSelector"
-                        + " or use a changeMoveSelector instead.");
+                throw new IllegalArgumentException("""
+                        The listChangeMoveSelector (%s) is configured to use a planning variable (%s), \
+                        which is not a planning list variable.
+                        Either fix your annotations and use a @%s on the variable to make it work with listChangeMoveSelector
+                        or use a changeMoveSelector instead."""
+                        .formatted(config, onlyVariableDescriptor, PlanningListVariable.class.getSimpleName()));
             }
             if (!onlyDestinationVariableDescriptor.isListVariable()) {
-                throw new IllegalArgumentException("The destinationSelector (" + destinationSelectorConfig
-                        + ") is configured to use a planning variable (" + onlyDestinationVariableDescriptor
-                        + "), which is not a planning list variable.");
+                throw new IllegalArgumentException(
+                        "The destinationSelector (%s) is configured to use a planning variable (%s), which is not a planning list variable."
+                                .formatted(destinationSelectorConfig, onlyDestinationVariableDescriptor));
             }
             if (onlyVariableDescriptor != onlyDestinationVariableDescriptor) {
-                throw new IllegalArgumentException("The listChangeMoveSelector's valueSelector ("
-                        + valueSelectorConfig
-                        + ") and destinationSelector's valueSelector ("
-                        + destinationValueSelectorConfig
-                        + ") must be configured for the same planning variable.");
+                throw new IllegalArgumentException(
+                        "The listChangeMoveSelector's valueSelector (%s) and destinationSelector's valueSelector (%s) must be configured for the same planning variable."
+                                .formatted(valueSelectorConfig, destinationValueSelectorConfig));
             }
             if (onlyEntityDescriptor != null) {
                 // No need for unfolding or deducing
@@ -125,12 +124,14 @@ protected MoveSelectorConfig<?> buildUnfoldedMoveSelectorConfig(HeuristicConfigP
                             .toList());
         }
         if (variableDescriptorList.isEmpty()) {
-            throw new IllegalArgumentException("The listChangeMoveSelector (" + config
-                    + ") cannot unfold because there are no planning list variables.");
+            throw new IllegalArgumentException(
+                    "The listChangeMoveSelector (%s) cannot unfold because there are no planning list variables."
+                            .formatted(config));
         }
         if (variableDescriptorList.size() > 1) {
-            throw new IllegalArgumentException("The listChangeMoveSelector (" + config
-                    + ") cannot unfold because there are multiple planning list variables.");
+            throw new IllegalArgumentException(
+                    "The listChangeMoveSelector (%s) cannot unfold because there are multiple planning list variables."
+                            .formatted(config));
         }
         var listChangeMoveSelectorConfig =
                 buildChildMoveSelectorConfig(variableDescriptorList.get(0), valueSelectorConfig, destinationSelectorConfig);

core/src/main/java/ai/timefold/solver/core/impl/heuristic/selector/value/ValueSelectorFactory.java

@@ -185,8 +185,7 @@ Check your solver configuration. If that class (%s) is not in the entityClassSet
     protected boolean determineBaseRandomSelection(GenuineVariableDescriptor<Solution_> variableDescriptor,
             SelectionCacheType resolvedCacheType, SelectionOrder resolvedSelectionOrder) {
         return switch (resolvedSelectionOrder) {
-            case ORIGINAL -> false;
-            case SORTED, SHUFFLED, PROBABILISTIC ->
+            case ORIGINAL, SORTED, SHUFFLED, PROBABILISTIC ->
                 // baseValueSelector and lower should be ORIGINAL if they are going to get cached completely
                 false;
             case RANDOM ->

core/src/main/java/ai/timefold/solver/core/impl/score/director/easy/EasyScoreDirector.java

@@ -48,10 +48,11 @@ public Score_ calculateScore() {
         variableListenerSupport.assertNotificationQueuesAreEmpty();
         Score_ score = easyScoreCalculator.calculateScore(workingSolution);
         if (!score.isSolutionInitialized()) {
-            throw new IllegalStateException("The score (" + this + ")'s initScore (" + score.initScore()
-                    + ") should be 0.\n"
-                    + "Maybe the score calculator (" + easyScoreCalculator.getClass() + ") is calculating "
-                    + "the initScore too, although it's the score director's responsibility.");
+            throw new IllegalStateException("""
+                    The score (%s)'s initScore (%d) should be 0.
+                    Maybe the score calculator (%s) is calculating the initScore too, \
+                    although it's the score director's responsibility."""
+                    .formatted(this, score.initScore(), easyScoreCalculator.getClass()));
         }
         int workingInitScore = getWorkingInitScore();
         if (workingInitScore != 0) {
@@ -69,8 +70,8 @@ public Score_ calculateScore() {
      */
     @Override
     public Map<String, ConstraintMatchTotal<Score_>> getConstraintMatchTotalMap() {
-        throw new IllegalStateException(ConstraintMatch.class.getSimpleName()
-                + " is not supported by " + EasyScoreDirector.class.getSimpleName() + ".");
+        throw new IllegalStateException("%s is not supported by %s."
+                .formatted(ConstraintMatch.class.getSimpleName(), EasyScoreDirector.class.getSimpleName()));
     }
 
     /**
@@ -81,8 +82,8 @@ public Map<String, ConstraintMatchTotal<Score_>> getConstraintMatchTotalMap() {
      */
     @Override
     public Map<Object, Indictment<Score_>> getIndictmentMap() {
-        throw new IllegalStateException(ConstraintMatch.class.getSimpleName()
-                + " is not supported by " + EasyScoreDirector.class.getSimpleName() + ".");
+        throw new IllegalStateException("%s is not supported by %s."
+                .formatted(ConstraintMatch.class.getSimpleName(), EasyScoreDirector.class.getSimpleName()));
     }
 
     @Override

core/src/main/java/ai/timefold/solver/core/impl/score/stream/common/InnerConstraintFactory.java

@@ -2,7 +2,6 @@
 
 import static ai.timefold.solver.core.api.score.stream.Joiners.lessThan;
 import static java.util.stream.Collectors.groupingBy;
-import static java.util.stream.Collectors.toList;
 
 import java.util.Arrays;
 import java.util.List;
@@ -42,9 +41,9 @@ private <A> DefaultBiJoiner<A, A> buildLessThanId(Class<A> sourceClass) {
         SolutionDescriptor<Solution_> solutionDescriptor = getSolutionDescriptor();
         MemberAccessor planningIdMemberAccessor = solutionDescriptor.getPlanningIdAccessor(sourceClass);
         if (planningIdMemberAccessor == null) {
-            throw new IllegalArgumentException("The fromClass (" + sourceClass + ") has no member with a @"
-                    + PlanningId.class.getSimpleName() + " annotation,"
-                    + " so the pairs cannot be made unique ([A,B] vs [B,A]).");
+            throw new IllegalArgumentException(
+                    "The fromClass (%s) has no member with a @%s annotation, so the pairs cannot be made unique ([A,B] vs [B,A])."
+                            .formatted(sourceClass, PlanningId.class.getSimpleName()));
         }
         Function<A, Comparable> planningIdGetter = planningIdMemberAccessor.getGetterFunction();
         return (DefaultBiJoiner<A, A>) lessThan(planningIdGetter);
@@ -74,34 +73,38 @@ public <A> void assertValidFromType(Class<A> fromType) {
             List<String> canonicalClassNameList = problemFactOrEntityClassSet.stream()
                     .map(Class::getCanonicalName)
                     .sorted()
-                    .collect(toList());
-            throw new IllegalArgumentException("Cannot use class (" + fromType.getCanonicalName()
-                    + ") in a constraint stream as it is neither the same as, nor a superclass or superinterface of "
-                    + "one of planning entities or problem facts.\n"
-                    + "Ensure that all from(), join(), ifExists() and ifNotExists() building blocks only reference "
-                    + "classes assignable from planning entities or problem facts (" + canonicalClassNameList + ") "
-                    + "annotated on the planning solution (" + solutionDescriptor.getSolutionClass().getCanonicalName()
-                    + ").");
+                    .toList();
+            throw new IllegalArgumentException("""
+                    Cannot use class (%s) in a constraint stream as it is neither the same as, \
+                    nor a superclass or superinterface of one of planning entities or problem facts.
+                    Ensure that all from(), join(), ifExists() and ifNotExists() building blocks \
+                    only reference classes assignable from planning entities \
+                    or problem facts (%s) annotated on the planning solution (%s)."""
+                    .formatted(fromType.getCanonicalName(), canonicalClassNameList,
+                            solutionDescriptor.getSolutionClass().getCanonicalName()));
         }
     }
 
+    @SuppressWarnings("unchecked")
     public List<Constraint_> buildConstraints(ConstraintProvider constraintProvider) {
         Constraint[] constraints = Objects.requireNonNull(constraintProvider.defineConstraints(this),
                 () -> """
                         The constraintProvider class (%s)'s defineConstraints() must not return null."
                         Maybe return an empty array instead if there are no constraints."""
                         .formatted(constraintProvider.getClass()));
         if (Arrays.stream(constraints).anyMatch(Objects::isNull)) {
-            throw new IllegalStateException("The constraintProvider class (" + constraintProvider.getClass()
-                    + ")'s defineConstraints() must not contain an element that is null.\n"
-                    + "Maybe don't include any null elements in the " + Constraint.class.getSimpleName() + " array.");
+            throw new IllegalStateException("""
+                    The constraintProvider class (%s)'s defineConstraints() must not contain an element that is null.
+                    Maybe don't include any null elements in the %s array."""
+                    .formatted(constraintProvider.getClass(), Constraint.class.getSimpleName()));
         }
         // Fail fast on duplicate constraint IDs.
         Map<ConstraintRef, List<Constraint>> constraintsPerIdMap =
                 Arrays.stream(constraints).collect(groupingBy(Constraint::getConstraintRef));
         constraintsPerIdMap.forEach((constraintRef, duplicateConstraintList) -> {
             if (duplicateConstraintList.size() > 1) {
-                throw new IllegalStateException("There are multiple constraints with the same ID (" + constraintRef + ").");
+                throw new IllegalStateException("There are multiple constraints with the same ID (%s)."
+                        .formatted(constraintRef));
             }
         });
         return Arrays.stream(constraints)

persistence/jackson/src/main/java/ai/timefold/solver/jackson/api/domain/solution/ConstraintWeightOverridesSerializer.java

@@ -18,8 +18,8 @@ public void serialize(ConstraintWeightOverrides<Score_> constraintWeightOverride
             SerializerProvider serializerProvider) throws IOException {
         generator.writeStartObject();
         for (var constraintName : constraintWeightOverrides.getKnownConstraintNames()) {
-            var weight = constraintWeightOverrides.getConstraintWeight(constraintName);
-            generator.writeStringField(constraintName, Objects.requireNonNull(weight).toString());
+            var weight = Objects.requireNonNull(constraintWeightOverrides.getConstraintWeight(constraintName));
+            generator.writeStringField(constraintName, weight.toString());
         }
         generator.writeEndObject();
     }

spring-integration/spring-boot-autoconfigure/src/main/java/ai/timefold/solver/spring/boot/autoconfigure/TimefoldSolverAutoConfiguration.java

@@ -242,7 +242,7 @@ private void loadSolverConfig(IncludeAbstractClassesEntityScanner entityScanner,
         if (solverEntityClassList == null) {
             solverConfig.setEntityClassList(entityScanner.findEntityClassList());
         } else {
-            long entityClassCount = solverEntityClassList.stream()
+            var entityClassCount = solverEntityClassList.stream()
                     .filter(Objects::nonNull)
                     .count();
             if (entityClassCount == 0L) {