PLANNER-793 Autodiscover problem facts without annotations through fl…

…ag on @Planningsolution

 (AKA deprecate AbstractSolution)

optaplanner-core/src/main/java/org/optaplanner/core/api/domain/autodetect/AutoDiscoverMemberType.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017 Red Hat, Inc. and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.optaplanner.core.api.domain.autodetect;
+
+import org.optaplanner.core.api.domain.solution.PlanningEntityCollectionProperty;
+import org.optaplanner.core.api.domain.solution.PlanningEntityProperty;
+import org.optaplanner.core.api.domain.solution.PlanningSolution;
+import org.optaplanner.core.api.domain.solution.drools.ProblemFactCollectionProperty;
+import org.optaplanner.core.api.domain.solution.drools.ProblemFactProperty;
+
+/**
+ * Determines if and how to automatically presume
+ * {@link ProblemFactCollectionProperty}, {@link ProblemFactProperty},
+ * {@link PlanningEntityCollectionProperty} and {@link PlanningEntityProperty} annotations
+ * on a {@link PlanningSolution}.
+ */
+public enum AutoDiscoverMemberType {
+    NONE,
+    FIELD,
+    GETTER;
+}

optaplanner-core/src/main/java/org/optaplanner/core/api/domain/solution/PlanningSolution.java

@@ -19,6 +19,7 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.Target;
 
+import org.optaplanner.core.api.domain.autodetect.AutoDiscoverMemberType;
 import org.optaplanner.core.api.domain.lookup.LookUpStrategyType;
 import org.optaplanner.core.api.domain.solution.cloner.SolutionCloner;
 import org.optaplanner.core.api.domain.solution.drools.ProblemFactCollectionProperty;
@@ -53,6 +54,11 @@
 @Retention(RUNTIME)
 public @interface PlanningSolution {
 
+    /**
+     * @return never null
+     */
+    AutoDiscoverMemberType autoDiscoverMemberType() default AutoDiscoverMemberType.NONE;
+
     /**
      * Overrides the default {@link SolutionCloner} to implement a custom {@link PlanningSolution} cloning implementation.
      * <p>

optaplanner-core/src/main/java/org/optaplanner/core/config/util/ConfigUtils.java

@@ -22,6 +22,8 @@
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -37,6 +39,7 @@
 import javax.script.ScriptException;
 
 import org.optaplanner.core.api.domain.lookup.PlanningId;
+import org.optaplanner.core.api.domain.variable.InverseRelationShadowVariable;
 import org.optaplanner.core.config.AbstractConfig;
 import org.optaplanner.core.impl.domain.common.AlphabeticMemberComparator;
 import org.optaplanner.core.impl.domain.common.ReflectionHelper;
@@ -338,6 +341,46 @@ public static Class<? extends Annotation> extractAnnotationClass(Member member,
         return annotationClass;
     }
 
+    public static Class<?> extractCollectionGenericTypeParameter(
+            String parentClassConcept, Class<?> parentClass,
+            Class<?> type, Type genericType,
+            Class<? extends Annotation> annotationClass, String memberName) {
+        if (!(genericType instanceof ParameterizedType)) {
+            throw new IllegalArgumentException("The " + parentClassConcept + " (" + parentClass + ") has a "
+                    + (annotationClass == null ? "auto discovered" : annotationClass.getSimpleName() + " annotated")
+                    + " member (" + memberName
+                    + ") with a member type (" + type
+                    + ") that returns a " + Collection.class.getSimpleName()
+                    + " which has no generic parameters.\n"
+                    + "Maybe the member (" + memberName + ") should return a typed "
+                    + Collection.class.getSimpleName() + ".");
+        }
+        ParameterizedType parameterizedType = (ParameterizedType) genericType;
+        Type[] typeArguments = parameterizedType.getActualTypeArguments();
+        if (typeArguments.length != 1) {
+            throw new IllegalArgumentException("The " + parentClassConcept + " (" + parentClass + ") has a "
+                    + (annotationClass == null ? "auto discovered" : annotationClass.getSimpleName() + " annotated")
+                    + " member (" + memberName
+                    + ") with a member type (" + type
+                    + ") which is parameterized collection with an unsupported number of generic parameters ("
+                    + typeArguments.length + ").");
+        }
+        Type typeArgument = typeArguments[0];
+        if (typeArgument instanceof ParameterizedType) {
+            // Remove the type parameters so it can be cast to a Class
+            typeArgument = ((ParameterizedType) typeArgument).getRawType();
+        }
+        if (!(typeArgument instanceof Class)) {
+            throw new IllegalArgumentException("The " + parentClassConcept + " (" + parentClass + ") has a "
+                    + (annotationClass == null ? "auto discovered" : annotationClass.getSimpleName() + " annotated")
+                    + " member (" + memberName
+                    + ") with a member type (" + type
+                    + ") which is parameterized collection with an unsupported type argument ("
+                    + typeArgument + ").");
+        }
+        return ((Class) typeArgument);
+    }
+
     public static MemberAccessor buildMemberAccessor(Member member, MemberAccessorType memberAccessorType, Class<? extends Annotation> annotationClass) {
         if (member instanceof Field) {
             Field field = (Field) member;