Polishing.

Introduce factory methods on RedisSet for easier construction of RediSet. Add javadoc.
Revise clear method to perform a DEL command instead of empty set intersection.

See #2037
Original Pull Request: #2105

Author: mp911de

src/main/java/org/springframework/data/redis/support/collections/DefaultRedisSet.java

@@ -16,11 +16,9 @@
 package org.springframework.data.redis.support.collections;
 
 import java.util.Collection;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;
-import java.util.UUID;
 
 import org.springframework.data.redis.connection.DataType;
 import org.springframework.data.redis.core.BoundSetOperations;
@@ -216,10 +214,7 @@ public boolean add(E e) {
 	 */
 	@Override
 	public void clear() {
-		// intersect the set with a non existing one
-		// TODO: find a safer way to clean the set
-		String randomKey = UUID.randomUUID().toString();
-		boundSetOps.intersectAndStore(Collections.singleton(randomKey), getKey());
+		boundSetOps.getOperations().delete(getKey());
 	}
 
 	/*

src/main/java/org/springframework/data/redis/support/collections/RedisSet.java

@@ -19,67 +19,85 @@
 import java.util.Iterator;
 import java.util.Set;
 
+import org.springframework.data.redis.core.RedisOperations;
+
 /**
  * Redis extension for the {@link Set} contract. Supports {@link Set} specific operations backed by Redis operations.
  *
  * @author Costin Leau
  * @author Christoph Strobl
+ * @author Mark Paluch
  */
 public interface RedisSet<E> extends RedisCollection<E>, Set<E> {
 
 	/**
-	 * Intersect this set and another {@link RedisSet}.
+	 * Constructs a new {@link RedisSet} instance.
+	 *
+	 * @param key Redis key of this set.
+	 * @param operations {@link RedisOperations} for the value type of this set.
+	 * @since 2.6
+	 */
+	static <E> RedisSet<E> create(String key, RedisOperations<String, E> operations) {
+		return new DefaultRedisSet<>(key, operations);
+	}
+
+	/**
+	 * Diff this set and another {@link RedisSet}.
 	 *
 	 * @param set must not be {@literal null}.
-	 * @return a {@link Set} containing the intersecting values.
+	 * @return a {@link Set} containing the values that differ.
 	 * @since 1.0
 	 */
-	Set<E> intersect(RedisSet<?> set);
+	Set<E> diff(RedisSet<?> set);
 
 	/**
-	 * Intersect this set and other {@link RedisSet}s.
+	 * Diff this set and other {@link RedisSet}s.
 	 *
 	 * @param sets must not be {@literal null}.
-	 * @return a {@link Set} containing the intersecting values.
+	 * @return a {@link Set} containing the values that differ.
 	 * @since 1.0
 	 */
-	Set<E> intersect(Collection<? extends RedisSet<?>> sets);
+	Set<E> diff(Collection<? extends RedisSet<?>> sets);
 
 	/**
-	 * Union this set and another {@link RedisSet}.
+	 * Create a new {@link RedisSet} by diffing this sorted set and {@link RedisSet} and store result in destination
+	 * {@code destKey}.
 	 *
 	 * @param set must not be {@literal null}.
-	 * @return a {@link Set} containing the combined values.
-	 * @since 2.6
+	 * @param destKey must not be {@literal null}.
+	 * @return a new {@link RedisSet} pointing at {@code destKey}.
+	 * @since 1.0
 	 */
-	Set<E> union(RedisSet<?> set);
+	RedisSet<E> diffAndStore(RedisSet<?> set, String destKey);
 
 	/**
-	 * Union this set and other {@link RedisSet}s.
+	 * Create a new {@link RedisSet} by diffing this sorted set and the collection {@link RedisSet} and store result in
+	 * destination {@code destKey}.
 	 *
 	 * @param sets must not be {@literal null}.
-	 * @return a {@link Set} containing the combined values.
+	 * @param destKey must not be {@literal null}.
+	 * @return a new {@link RedisSet} pointing at {@code destKey}.
 	 * @since 1.0
 	 */
-	Set<E> union(Collection<? extends RedisSet<?>> sets);
+	RedisSet<E> diffAndStore(Collection<? extends RedisSet<?>> sets, String destKey);
 
 	/**
-	 * Diff this set and another {@link RedisSet}.
+	 * Intersect this set and another {@link RedisSet}.
 	 *
 	 * @param set must not be {@literal null}.
-	 * @return a {@link Set} containing the values that differ.
+	 * @return a {@link Set} containing the intersecting values.
 	 * @since 1.0
 	 */
-	Set<E> diff(RedisSet<?> set);
+	Set<E> intersect(RedisSet<?> set);
 
 	/**
-	 * Diff this set and other {@link RedisSet}s.
+	 * Intersect this set and other {@link RedisSet}s.
 	 *
 	 * @param sets must not be {@literal null}.
-	 * @return a {@link Set} containing the values that differ.
+	 * @return a {@link Set} containing the intersecting values.
 	 * @since 1.0
 	 */
-	Set<E> diff(Collection<? extends RedisSet<?>> sets);
+	Set<E> intersect(Collection<? extends RedisSet<?>> sets);
 
 	/**
 	 * Create a new {@link RedisSet} by intersecting this sorted set and {@link RedisSet} and store result in destination
@@ -104,60 +122,56 @@ public interface RedisSet<E> extends RedisCollection<E>, Set<E> {
 	RedisSet<E> intersectAndStore(Collection<? extends RedisSet<?>> sets, String destKey);
 
 	/**
-	 * Create a new {@link RedisSet} by union this sorted set and {@link RedisSet} and store result in destination
-	 * {@code destKey}.
+	 * Get random element from the set.
 	 *
-	 * @param set must not be {@literal null}.
-	 * @param destKey must not be {@literal null}.
-	 * @return a new {@link RedisSet} pointing at {@code destKey}.
-	 * @since 1.0
+	 * @return
+	 * @since 2.6
 	 */
-	RedisSet<E> unionAndStore(RedisSet<?> set, String destKey);
+	E randomValue();
 
 	/**
-	 * Create a new {@link RedisSet} by union this sorted set and the collection {@link RedisSet} and store result in
-	 * destination {@code destKey}.
-	 *
-	 * @param sets must not be {@literal null}.
-	 * @param destKey must not be {@literal null}.
-	 * @return a new {@link RedisSet} pointing at {@code destKey}.
-	 * @since 1.0
+	 * @since 1.4
+	 * @return
 	 */
-	RedisSet<E> unionAndStore(Collection<? extends RedisSet<?>> sets, String destKey);
+	Iterator<E> scan();
 
 	/**
-	 * Get random element from the set.
+	 * Union this set and another {@link RedisSet}.
 	 *
-	 * @return
+	 * @param set must not be {@literal null}.
+	 * @return a {@link Set} containing the combined values.
 	 * @since 2.6
 	 */
-	E randomValue();
+	Set<E> union(RedisSet<?> set);
 
 	/**
-	 * Create a new {@link RedisSet} by diffing this sorted set and {@link RedisSet} and store result in destination
+	 * Union this set and other {@link RedisSet}s.
+	 *
+	 * @param sets must not be {@literal null}.
+	 * @return a {@link Set} containing the combined values.
+	 * @since 1.0
+	 */
+	Set<E> union(Collection<? extends RedisSet<?>> sets);
+
+	/**
+	 * Create a new {@link RedisSet} by union this sorted set and {@link RedisSet} and store result in destination
 	 * {@code destKey}.
 	 *
 	 * @param set must not be {@literal null}.
 	 * @param destKey must not be {@literal null}.
 	 * @return a new {@link RedisSet} pointing at {@code destKey}.
 	 * @since 1.0
 	 */
-	RedisSet<E> diffAndStore(RedisSet<?> set, String destKey);
+	RedisSet<E> unionAndStore(RedisSet<?> set, String destKey);
 
 	/**
-	 * Create a new {@link RedisSet} by diffing this sorted set and the collection {@link RedisSet} and store result in
+	 * Create a new {@link RedisSet} by union this sorted set and the collection {@link RedisSet} and store result in
 	 * destination {@code destKey}.
 	 *
 	 * @param sets must not be {@literal null}.
 	 * @param destKey must not be {@literal null}.
 	 * @return a new {@link RedisSet} pointing at {@code destKey}.
 	 * @since 1.0
 	 */
-	RedisSet<E> diffAndStore(Collection<? extends RedisSet<?>> sets, String destKey);
-
-	/**
-	 * @since 1.4
-	 * @return
-	 */
-	Iterator<E> scan();
+	RedisSet<E> unionAndStore(Collection<? extends RedisSet<?>> sets, String destKey);
 }

src/test/java/org/springframework/data/redis/connection/AbstractConnectionIntegrationTests.java

@@ -1587,6 +1587,7 @@ void lPosNonExisting() {
 
 	@Test
 	void testSAdd() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sMembers("myset"));
@@ -1595,6 +1596,7 @@ void testSAdd() {
 
 	@Test
 	void testSAddMultiple() {
+
 		actual.add(connection.sAdd("myset", "foo", "bar"));
 		actual.add(connection.sAdd("myset", "baz"));
 		actual.add(connection.sMembers("myset"));
@@ -1603,6 +1605,7 @@ void testSAddMultiple() {
 
 	@Test
 	void testSCard() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sCard("myset"));
@@ -1611,6 +1614,7 @@ void testSCard() {
 
 	@Test
 	void testSDiff() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sAdd("otherset", "bar"));
@@ -1620,6 +1624,7 @@ void testSDiff() {
 
 	@Test
 	void testSDiffStore() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sAdd("otherset", "bar"));
@@ -1630,6 +1635,7 @@ void testSDiffStore() {
 
 	@Test
 	void testSInter() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sAdd("otherset", "bar"));
@@ -1649,6 +1655,7 @@ void testSInterStore() {
 
 	@Test
 	void testSIsMember() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sIsMember("myset", "foo"));
@@ -1659,6 +1666,7 @@ void testSIsMember() {
 	@Test // GH-2037
 	@EnabledOnCommand("SMISMEMBER")
 	void testSMIsMember() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sMIsMember("myset", "foo", "bar", "baz"));
@@ -1667,6 +1675,7 @@ void testSMIsMember() {
 
 	@Test
 	void testSMove() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sAdd("otherset", "bar"));
@@ -1676,6 +1685,7 @@ void testSMove() {
 
 	@Test
 	void testSPop() {
+
 		actual.add(connection.sAdd("myset", "foo"));
 		actual.add(connection.sAdd("myset", "bar"));
 		actual.add(connection.sPop("myset"));

src/test/java/org/springframework/data/redis/support/collections/AbstractRedisSetIntegrationTests.java

@@ -72,6 +72,7 @@ private RedisSet<T> createSetFor(String key) {
 	@ParameterizedRedisTest // GH-2037
 	@EnabledOnCommand("SMISMEMBER")
 	void testContainsAll() {
+		
 		T t1 = getT();
 		T t2 = getT();
 		T t3 = getT();