Introduce EmptyModel and EmptyModelFilter

core/src/main/java/org/genesys/blocks/model/BasicModel.java

@@ -15,8 +15,6 @@
  */
 package org.genesys.blocks.model;
 
-import java.io.Serializable;
-
 import javax.persistence.Column;
 import javax.persistence.GeneratedValue;
 import javax.persistence.GenerationType;
@@ -24,18 +22,14 @@ import javax.persistence.Id;
 import javax.persistence.MappedSuperclass;
 import javax.persistence.Transient;
 
-import org.genesys.blocks.util.JsonClassNameWriter;
-
 import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonView;
-import com.fasterxml.jackson.databind.annotation.JsonAppend;
 
 /**
  * The Class BasicModel.
  */
 @MappedSuperclass
-@JsonAppend(props = { @JsonAppend.Prop(name = "_class", value = JsonClassNameWriter.class, type = String.class) })
-public class BasicModel implements EntityId, Serializable {
+public class BasicModel extends EmptyModel {
 
 	/** The Constant serialVersionUID. */
 	private static final long serialVersionUID = 2709998920148999956L;

core/src/main/java/org/genesys/blocks/model/EmptyModel.java

+/*
+ * Copyright 2020 Global Crop Diversity Trust
+ *
+ * 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.genesys.blocks.model;
+
+import java.io.Serializable;
+
+import javax.persistence.MappedSuperclass;
+
+import org.genesys.blocks.util.JsonClassNameWriter;
+
+import com.fasterxml.jackson.annotation.JsonIdentityInfo;
+import com.fasterxml.jackson.annotation.ObjectIdGenerators;
+import com.fasterxml.jackson.databind.annotation.JsonAppend;
+
+@MappedSuperclass
+@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id")
+@JsonAppend(props = { @JsonAppend.Prop(name = "_class", value = JsonClassNameWriter.class, type = String.class) })
+public abstract class EmptyModel implements EntityId, Serializable {
+
+	/** The Constant serialVersionUID. */
+	private static final long serialVersionUID = 5934941826741972456L;
+
+}

core/src/main/java/org/genesys/blocks/model/filters/BasicModelFilter.java

@@ -15,16 +15,7 @@
  */
 package org.genesys.blocks.model.filters;
 
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
-import org.apache.commons.collections4.CollectionUtils;
 import org.genesys.blocks.model.BasicModel;
-import org.genesys.blocks.model.QBasicModel;
-
-import com.querydsl.core.types.Predicate;
-import com.querydsl.core.types.dsl.EntityPathBase;
 
 /**
  * {@link BasicModel} match by sample filters.
@@ -32,36 +23,6 @@ import com.querydsl.core.types.dsl.EntityPathBase;
  * @param <T> the generic type
  * @param <R> the generic type
  */
-public abstract class BasicModelFilter<T extends BasicModelFilter<T, R>, R extends BasicModel> extends SuperModelFilter<T, R> {
-
-	/** The id. */
-	public Set<Long> id;
-
-	/**
-	 * Collects list of filter predicates
-	 *
-	 * @param instance the instance of Q-type of <em>R</em>
-	 * @param basicModel the basic model
-	 * @return list of predicates
-	 */
-	protected List<Predicate> collectPredicates(final EntityPathBase<R> instance, final QBasicModel basicModel) {
-		List<Predicate> predicates = super.collectPredicates(instance);
-		if (CollectionUtils.isNotEmpty(id)) {
-			predicates.add(basicModel.id.in(id));
-		}
-		return predicates;
-	}
-
-	/**
-	 * Id.
-	 *
-	 * @return the sets the
-	 */
-	public synchronized Set<Long> id() {
-		if (id == null) {
-			id = new HashSet<>();
-		}
-		return id;
-	}
+public abstract class BasicModelFilter<T extends BasicModelFilter<T, R>, R extends BasicModel> extends EmptyModelFilter<T, R> {
 
 }

core/src/main/java/org/genesys/blocks/model/filters/EmptyModelFilter.java

+/*
+ * Copyright 2020 Global Crop Diversity Trust
+ *
+ * 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.genesys.blocks.model.filters;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.commons.collections4.CollectionUtils;
+import org.genesys.blocks.model.BasicModel;
+import org.genesys.blocks.model.EmptyModel;
+import org.genesys.blocks.model.QBasicModel;
+
+import com.querydsl.core.types.Predicate;
+import com.querydsl.core.types.dsl.EntityPathBase;
+
+/**
+ * {@link BasicModel} match by sample filters.
+ *
+ * @param <T> the generic type
+ * @param <R> the generic type
+ */
+public abstract class EmptyModelFilter<T extends EmptyModelFilter<T, R>, R extends EmptyModel> extends SuperModelFilter<T, R> {
+
+	/** The id. */
+	public Set<Long> id;
+
+	/**
+	 * Collects list of filter predicates
+	 *
+	 * @param instance the instance of Q-type of <em>R</em>
+	 * @param basicModel the basic model
+	 * @return list of predicates
+	 */
+	protected List<Predicate> collectPredicates(final EntityPathBase<R> instance, final QBasicModel basicModel) {
+		List<Predicate> predicates = super.collectPredicates(instance);
+		if (CollectionUtils.isNotEmpty(id)) {
+			predicates.add(basicModel.id.in(id));
+		}
+		return predicates;
+	}
+
+	/**
+	 * Id.
+	 *
+	 * @return the sets the
+	 */
+	public synchronized Set<Long> id() {
+		if (id == null) {
+			id = new HashSet<>();
+		}
+		return id;
+	}
+
+}