DATAREDIS-612 - Polishing.

Introduce factory methods for ChannelTopic and PatternTopic.

Original Pull Request: #295

src/main/java/org/springframework/data/redis/listener/ChannelTopic.java

@@ -42,6 +42,17 @@ public class ChannelTopic implements Topic {
 		this.channelName = name;
 	}
 
+	/**
+	 * Create a new {@link ChannelTopic} for channel subscriptions.
+	 * 
+	 * @param name the channel name, must not be {@literal null} or empty.
+	 * @return the {@link ChannelTopic} for {@code channelName}.
+	 * @since 2.1
+	 */
+	public static ChannelTopic of(String name) {
+		return new ChannelTopic(name);
+	}
+
 	/**
 	 * @return topic name.
 	 */

src/main/java/org/springframework/data/redis/listener/PatternTopic.java

@@ -42,6 +42,17 @@ public class PatternTopic implements Topic {
 		this.channelPattern = pattern;
 	}
 
+	/**
+	 * Create a new {@link PatternTopic} for channel subscriptions based on a {@code pattern}.
+	 *
+	 * @param pattern the channel pattern, must not be {@literal null} or empty.
+	 * @return the {@link PatternTopic} for {@code pattern}.
+	 * @since 2.1
+	 */
+	static PatternTopic of(String pattern) {
+		return new PatternTopic(pattern);
+	}
+
 	/**
 	 * @return channel pattern.
 	 */