Internal API improvements about JoinType

src/main/java/com/kodgemisi/specification/CriteriaOperation.java

@@ -5,11 +5,10 @@
  *
  * @author Destan Sarpkaya
  * @author Ersan Ceylan
+ * @author Sedat Gokcen
  */
-enum CriteriaOperation {
+enum CriteriaOperation implements Operation {
 
-	JOIN,
-	JOIN_FETCH,
 	EQUAL,
 	EQUAL_TO_MANY,
 	EQUAL_TO_ONE,

src/main/java/com/kodgemisi/specification/FilterCriteria.java

@@ -4,14 +4,13 @@
 import lombok.Setter;
 import org.springframework.lang.NonNull;
 
-import javax.persistence.criteria.JoinType;
-
 /**
  * Created on October, 2018
  *
  * @author Destan Sarpkaya
  * @author Ersan Ceylan
  * @author Gökhan Birinci
+ * @author Sedat Gokcen
  */
 
 /**
@@ -28,38 +27,25 @@ class FilterCriteria<T> {
 	private final T value;
 
 	@NonNull
-	private final CriteriaOperation operation;
-
-	private final JoinType joinType;
+	private final Operation operation;
 
 	private final Class<T> clazz;
 
 	private final RelationType relationType;
 
-	FilterCriteria(String key, T value, CriteriaOperation operation, Class<T> clazz) {
+	FilterCriteria(String key, T value, Operation operation, Class<T> clazz, RelationType relationType) {
 		this.key = key;
 		this.value = value;
 		this.operation = operation;
-		this.joinType = null;
 		this.clazz = clazz;
-		this.relationType = RelationType.NO_RELATION;
+		this.relationType = relationType;
 	}
 
-	FilterCriteria(String key, T value, CriteriaOperation operation, Class<T> clazz, RelationType relationType) {
-		this.key = key;
-		this.value = value;
-		this.operation = operation;
-		this.joinType = null;
-		this.clazz = clazz;
-		this.relationType = relationType;
+	FilterCriteria(String key, T value, Operation operation, Class<T> clazz) {
+		this(key, value, operation, clazz, RelationType.NO_RELATION);
 	}
 
-	FilterCriteria(String key, CriteriaOperation operation, JoinType joinType, Class<T> clazz) {
-		this.key = key;
-		this.operation = operation;
-		this.joinType = joinType;
-		this.clazz = clazz;
-		this.value = null;
-		this.relationType = RelationType.NO_RELATION;
+	FilterCriteria(String key, Operation operation, Class<T> clazz) {
+		this(key, null, operation, clazz, RelationType.NO_RELATION);
 	}
 }

src/main/java/com/kodgemisi/specification/GenericSpecification.java

@@ -20,6 +20,7 @@
  * @author Destan Sarpkaya
  * @author Ersan Ceylan
  * @author Gökhan Birinci
+ * @author Sedat Gokcen
  */
 
 @SuppressWarnings({"rawtypes", "unchecked"})
@@ -31,70 +32,78 @@ class GenericSpecification<E, T, C extends Comparable<? super C>> implements Spe
 	@Override
 	public Predicate toPredicate(Root<E> root, CriteriaQuery<?> query, CriteriaBuilder criteriaBuilder) {
 
-		final CriteriaOperation operation = filterCriteria.getOperation();
+		final Operation operation = filterCriteria.getOperation();
 		final String key = filterCriteria.getKey();
 
-		switch (operation) {
-		case JOIN: {
-			final JoinType joinType = filterCriteria.getJoinType();
-			root.join(key, joinType);
+		if (operation instanceof JoinOperation) {
+			JoinOperation joinOperation = (JoinOperation) operation;
+			processJoinOperation(joinOperation, key, root, query);
 			return null;
 		}
 
-		case JOIN_FETCH: {
-			final Class clazz = query.getResultType();
-			final JoinType joinType = filterCriteria.getJoinType();
-			if (clazz.equals(Long.class) || clazz.equals(long.class)) {
-				// If clazz is long then it's a count query for pageable
-				root.join(key, joinType);
-				return null;
+		final CriteriaOperation criteriaOperation = (CriteriaOperation) operation;
+
+		switch (criteriaOperation) {
+			case EQUAL: {
+				final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
+				return criteriaBuilder.equal(path, filterCriteria.getValue());
 			}
-			else {
-				root.fetch(key, joinType);
-				return null;
+
+			case LIKE: {
+				final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
+				return criteriaBuilder.like(path.as(String.class), "%" + filterCriteria.getValue() + "%");
 			}
-		}
-		case EQUAL: {
-			final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
-			return criteriaBuilder.equal(path, filterCriteria.getValue());
-		}
 
-		case LIKE: {
-			final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
-			return criteriaBuilder.like(path.as(String.class), "%" + filterCriteria.getValue() + "%");
-		}
+			case IN: {
+				final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
+				return path.in(filterCriteria.getValue());
+			}
 
-		case IN: {
-			final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
-			return path.in(filterCriteria.getValue());
-		}
+			case GREATER_THAN: {
+				final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
+				final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
+				return criteriaBuilder.greaterThan(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
+			}
 
-		case GREATER_THAN: {
-			final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
-			final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
-			return criteriaBuilder.greaterThan(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
-		}
+			case GREATER_THAN_OR_EQUAL_TO: {
+				final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
+				final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
+				return criteriaBuilder.greaterThanOrEqualTo(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
+			}
 
-		case GREATER_THAN_OR_EQUAL_TO: {
-			final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
-			final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
-			return criteriaBuilder.greaterThanOrEqualTo(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
-		}
+			case LESS_THAN: {
+				final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
+				final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
+				return criteriaBuilder.lessThan(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
+			}
+
+			case LESS_THAN_OR_EQUAL_TO: {
+				final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
+				final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
+				return criteriaBuilder.lessThanOrEqualTo(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
+			}
 
-		case LESS_THAN: {
-			final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
-			final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
-			return criteriaBuilder.lessThan(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
+			default:
+				return null;
 		}
+	}
+
+	private void processJoinOperation(JoinOperation joinOperation, String key, Root<E> root, CriteriaQuery<?> query) {
+		final JoinType joinType = joinOperation.getType();
 
-		case LESS_THAN_OR_EQUAL_TO: {
-			final ComparableFilterCriteria<C> comparableFilterCriteria = getComparableFilterCriteria();
-			final Path<?> path = resolvePath(root, filterCriteria.getKey(), filterCriteria.getRelationType());
-			return criteriaBuilder.lessThanOrEqualTo(path.as(comparableFilterCriteria.getClazz()), comparableFilterCriteria.getValue());
+		if (joinOperation == JoinOperation.JOIN) {
+			root.join(key, joinType);
+			return;
 		}
 
-		default:
-			return null;
+		final Class clazz = query.getResultType();
+
+		if (clazz.equals(Long.class) || clazz.equals(long.class)) {
+			// If clazz is long then it's a count query for pageable
+			root.join(key, joinType);
+		}
+		else {
+			root.fetch(key, joinType);
 		}
 	}
 

src/main/java/com/kodgemisi/specification/GenericSpecificationBuilder.java

@@ -27,6 +27,7 @@
  * @author Destan Sarpkaya
  * @author Ersan Ceylan
  * @author Gökhan Birinci
+ * @author Sedat Gokcen
  */
 public class GenericSpecificationBuilder<E> {
 
@@ -55,8 +56,8 @@ public static <E> GenericSpecificationBuilder<E> of(Class<E> clazz) {
 		return new GenericSpecificationBuilder<>();
 	}
 
-	private GenericSpecificationBuilder<E> addCriteria(String key, CriteriaOperation operation, JoinType joinType) {
-		filterCriteriaList.add(new FilterCriteria<Void>(key, operation, joinType, Void.class));
+	private GenericSpecificationBuilder<E> addCriteria(String key, Operation operation) {
+		filterCriteriaList.add(new FilterCriteria<Void>(key, operation, Void.class));
 		return this;
 	}
 
@@ -82,7 +83,7 @@ private <C extends Comparable<? super C>> GenericSpecificationBuilder<E>  addCom
 	 * @return
 	 */
 	public GenericSpecificationBuilder<E> join(String key) {
-		return addCriteria(key, CriteriaOperation.JOIN, JoinType.INNER);
+		return addCriteria(key, JoinOperation.JOIN.type(JoinType.INNER));
 	}
 
 	/**
@@ -92,7 +93,7 @@ public GenericSpecificationBuilder<E> join(String key) {
 	 * @return
 	 */
 	public GenericSpecificationBuilder<E> join(String key, JoinType joinType) {
-		return addCriteria(key, CriteriaOperation.JOIN, joinType);
+		return addCriteria(key, JoinOperation.JOIN.type(joinType));
 	}
 
 	/**
@@ -101,7 +102,7 @@ public GenericSpecificationBuilder<E> join(String key, JoinType joinType) {
 	 * @return
 	 */
 	public GenericSpecificationBuilder<E> joinFetch(String key) {
-		return addCriteria(key, CriteriaOperation.JOIN_FETCH, JoinType.INNER);
+		return addCriteria(key, JoinOperation.JOIN_FETCH.type(JoinType.INNER));
 	}
 
 	/**
@@ -111,7 +112,7 @@ public GenericSpecificationBuilder<E> joinFetch(String key) {
 	 * @return
 	 */
 	public GenericSpecificationBuilder<E> joinFetch(String key, JoinType joinType) {
-		return addCriteria(key, CriteriaOperation.JOIN_FETCH, joinType);
+		return addCriteria(key, JoinOperation.JOIN_FETCH.type(joinType));
 	}
 
 	/**

src/main/java/com/kodgemisi/specification/JoinOperation.java

@@ -0,0 +1,24 @@
+package com.kodgemisi.specification;
+
+import javax.persistence.criteria.JoinType;
+
+/**
+ * Created on November, 2018
+ *
+ * @author Sedat Gokcen
+ */
+public enum JoinOperation implements Operation {
+    JOIN,
+    JOIN_FETCH;
+
+    private JoinType type = JoinType.INNER;
+
+    public JoinOperation type(JoinType type) {
+        this.type = type;
+        return this;
+    }
+
+    public JoinType getType() {
+        return type;
+    }
+}

src/main/java/com/kodgemisi/specification/Operation.java

@@ -0,0 +1,9 @@
+package com.kodgemisi.specification;
+
+/**
+ * Created on November, 2018
+ *
+ * @author Sedat Gokcen
+ */
+interface Operation {
+}