INT-3367: Add GemfireMetadataStore

JIRA: https://jira.spring.io/browse/INT-3367

INT-3367 Polishing

Rename test class; move to metadata package; doc polishing.

spring-integration-gemfire/src/main/java/org/springframework/integration/gemfire/metadata/GemfireMetadataStore.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2014 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
+ *
+ *      http://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.integration.gemfire.metadata;
+
+import org.springframework.integration.metadata.ConcurrentMetadataStore;
+import org.springframework.util.Assert;
+
+import com.gemstone.gemfire.cache.Cache;
+import com.gemstone.gemfire.cache.Region;
+import com.gemstone.gemfire.cache.Scope;
+
+/**
+ * Gemfire implementation of {@link ConcurrentMetadataStore}.
+ * Use this {@link org.springframework.integration.metadata.MetadataStore}
+ * to achieve meta-data persistence shared across application instances and
+ * restarts.
+ *
+ * @author Artem Bilan
+ * @since 4.0
+ */
+public class GemfireMetadataStore implements ConcurrentMetadataStore {
+
+	public static final String KEY = "MetaData";
+
+	private final Region<String, String> region;
+
+	public GemfireMetadataStore(Cache cache) {
+		Assert.notNull(cache, "'cache' must not be null");
+		this.region = cache.<String, String>createRegionFactory().setScope(Scope.LOCAL).create(KEY);
+	}
+
+	public GemfireMetadataStore(Region<String, String> region) {
+		Assert.notNull(region, "'region' must not be null");
+		this.region = region;
+	}
+
+	@Override
+	public void put(String key, String value) {
+		Assert.notNull(key, "'key' must not be null.");
+		Assert.notNull(value, "'value' must not be null.");
+		this.region.put(key, value);
+	}
+
+	@Override
+	public String putIfAbsent(String key, String value) {
+		Assert.notNull(key, "'key' must not be null.");
+		Assert.notNull(value, "'value' must not be null.");
+		return this.region.putIfAbsent(key, value);
+	}
+
+	@Override
+	public boolean replace(String key, String oldValue, String newValue) {
+		Assert.notNull(key, "'key' must not be null.");
+		Assert.notNull(oldValue, "'oldValue' must not be null.");
+		Assert.notNull(newValue, "'newValue' must not be null.");
+		return this.region.replace(key, oldValue, newValue);
+	}
+
+	@Override
+	public String get(String key) {
+		Assert.notNull(key, "'key' must not be null.");
+		return this.region.get(key);
+	}
+
+	@Override
+	public String remove(String key) {
+		Assert.notNull(key, "'key' must not be null.");
+		return this.region.remove(key);
+	}
+
+}

spring-integration-gemfire/src/main/java/org/springframework/integration/gemfire/metadata/package-info.java

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+/**
+ * Provides classes for the Gemfire MetadataStore.
+ */
+package org.springframework.integration.gemfire.metadata;