Add a concrete o.s.g.cache.RepositoryCacheLoader class, which implements org.apache.geode.cache.CacheLoader and uses (delegates to) a Spring Data CrudRepository.

2019-05-09 19:52:09 -07:00
parent c33d75db27
commit 7617fddd78
2 changed files with 202 additions and 0 deletions
--- a/spring-geode/src/main/java/org/springframework/geode/cache/RepositoryCacheLoader.java
+++ b/spring-geode/src/main/java/org/springframework/geode/cache/RepositoryCacheLoader.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2019 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.geode.cache;
+
+import java.util.function.Supplier;
+
+import org.apache.geode.cache.CacheLoader;
+import org.apache.geode.cache.CacheLoaderException;
+import org.apache.geode.cache.CacheRuntimeException;
+import org.apache.geode.cache.LoaderHelper;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.geode.cache.support.RepositoryCacheLoaderWriterSupport;
+
+/**
+ * A {@link CacheLoader} implementation backed by a Spring Data {@link CrudRepository} used to load an entity
+ * from an external data source.
+ *
+ * @author John Blum
+ * @see org.apache.geode.cache.CacheLoader
+ * @see org.springframework.data.repository.CrudRepository
+ * @see org.springframework.geode.cache.support.CacheLoaderSupport
+ * @since 1.1.0
+ */
+@SuppressWarnings("unused")
+public class RepositoryCacheLoader<T, ID> extends RepositoryCacheLoaderWriterSupport<T, ID> {
+
+  protected static final String CACHE_LOAD_EXCEPTION_MESSAGE = "Error while loading Entity [%s] with Repository [%s]";
+
+  public RepositoryCacheLoader(CrudRepository<T, ID> repository) {
+    super(repository);
+  }
+
+  @Override
+  public T load(LoaderHelper<ID, T> helper) throws CacheLoaderException {
+
+    try {
+      return getRepository().findById(helper.getKey()).orElse(null);
+    }
+    catch (Exception cause) {
+      throw newCacheRuntimeException(() -> String.format(CACHE_LOAD_EXCEPTION_MESSAGE,
+          helper.getKey(), getRepository().getClass().getName()), cause);
+    }
+  }
+
+  @Override
+  protected CacheRuntimeException newCacheRuntimeException(Supplier<String> messageSupplier, Throwable cause) {
+    return new CacheLoaderException(messageSupplier.get(), cause);
+  }
+}