Support adding a key prefix for keyspaces.

We now support prefixing keyspaces by introducing PrefixKeyspaceResolver.

Closes #461

src/main/java/org/springframework/data/keyvalue/core/mapping/AnnotationBasedKeySpaceResolver.java

@@ -31,7 +31,7 @@ import org.springframework.util.ClassUtils;
  * @author Oliver Gierke
  * @author Mark Paluch
  */
-enum AnnotationBasedKeySpaceResolver implements KeySpaceResolver {
+public enum AnnotationBasedKeySpaceResolver implements KeySpaceResolver {
 
 	INSTANCE;
 

src/main/java/org/springframework/data/keyvalue/core/mapping/PrefixKeyspaceResolver.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2022 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.springframework.data.keyvalue.core.mapping;
+
+import org.springframework.util.Assert;
+
+/**
+ * {@link KeySpaceResolver} prefixing the {@literal keyspace} with a static prefix after determining the keyspace from a
+ * delegate {@link KeySpaceResolver}.
+ *
+ * @author Mark Paluch
+ * @since 3.0
+ */
+public class PrefixKeyspaceResolver implements KeySpaceResolver {
+
+	private final String prefix;
+	private final KeySpaceResolver delegate;
+
+	public PrefixKeyspaceResolver(String prefix, KeySpaceResolver delegate) {
+
+		Assert.notNull(prefix, "Prefix must not be null");
+		Assert.notNull(delegate, "Delegate KeySpaceResolver must not be null");
+
+		this.prefix = prefix;
+		this.delegate = delegate;
+	}
+
+	@Override
+	public String resolveKeySpace(Class<?> type) {
+		return prefix + delegate.resolveKeySpace(type);
+	}
+
+}

src/main/java/org/springframework/data/keyvalue/core/mapping/context/KeyValueMappingContext.java

@@ -54,10 +54,19 @@ public class KeyValueMappingContext<E extends KeyValuePersistentEntity<?, P>, P
 		this.fallbackKeySpaceResolver = fallbackKeySpaceResolver;
 	}
 
+	/**
+	 * @return the current fallback KeySpaceResolver. Can be {@literal null}.
+	 * @since 3.0
+	 */
+	@Nullable
+	public KeySpaceResolver getFallbackKeySpaceResolver() {
+		return fallbackKeySpaceResolver;
+	}
+
 	@Override
 	@SuppressWarnings("unchecked")
 	protected <T> E createPersistentEntity(TypeInformation<T> typeInformation) {
-		return (E) new BasicKeyValuePersistentEntity<T, P>(typeInformation, fallbackKeySpaceResolver);
+		return (E) new BasicKeyValuePersistentEntity<T, P>(typeInformation, getFallbackKeySpaceResolver());
 	}
 
 	@Override