Add support to clear cache by key pattern.

Closes #2379
Original pull request: #2380.

Author: JosRoseboom

src/main/java/org/springframework/data/redis/cache/RedisCache.java

@@ -45,6 +45,7 @@
  * @author Christoph Strobl
  * @author Mark Paluch
  * @author Piotr Mionskowski
+ * @author Jos Roseboom
  * @see RedisCacheConfiguration
  * @see RedisCacheWriter
  * @since 2.0
@@ -174,8 +175,19 @@ public void evict(Object key) {
 
 	@Override
 	public void clear() {
+		clearByPattern("*");
+	}
 
-		byte[] pattern = conversionService.convert(createCacheKey("*"), byte[].class);
+	/**
+	 * <p>Clear keys that match the provided pattern.</p>
+	 * <br />
+	 * <p>Useful when the cache keys consists of multiple parameters. For example:
+	 * a cache key consists of a brand id and a country id. Now country 42 has relevant data updated. We want to clear all
+	 * the caches that involve country 42, regardless the brand. That can be done by clearByPattern("*42")</p>
+	 * @param keyPattern the pattern of the key
+	 */
+	public void clearByPattern(String keyPattern) {
+		byte[] pattern = conversionService.convert(createCacheKey(keyPattern), byte[].class);
 		cacheWriter.clean(name, pattern);
 	}
 

src/test/java/org/springframework/data/redis/cache/RedisCacheTests.java

@@ -61,6 +61,7 @@
  * @author Christoph Strobl
  * @author Mark Paluch
  * @author Piotr Mionskowski
+ * @author Jos Roseboom
  */
 @MethodSource("testParams")
 public class RedisCacheTests {
@@ -108,6 +109,32 @@ void putShouldAddEntry() {
 		});
 	}
 
+	@ParameterizedRedisTest // GH-2379
+	void cacheShouldBeClearedByPattern() {
+
+		cache.put(key, sample);
+
+		final String keyPattern = "*" + key.substring(1);
+		cache.clearByPattern(keyPattern);
+
+		doWithConnection(connection -> {
+			assertThat(connection.exists(binaryCacheKey)).isFalse();
+		});
+	}
+
+	@ParameterizedRedisTest // GH-2379
+	void cacheShouldNotBeClearedIfNoPatternMatch() {
+
+		cache.put(key, sample);
+
+		final String keyPattern = "*" + key.substring(1) + "tail";
+		cache.clearByPattern(keyPattern);
+
+		doWithConnection(connection -> {
+			assertThat(connection.exists(binaryCacheKey)).isTrue();
+		});
+	}
+
 	@ParameterizedRedisTest // DATAREDIS-481
 	void putNullShouldAddEntryForNullValue() {