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

2019-05-09 19:51:11 -07:00
parent a1300c5fc5
commit c33d75db27
2 changed files with 249 additions and 0 deletions
--- a/spring-geode/src/main/java/org/springframework/geode/cache/RepositoryCacheWriter.java
+++ b/spring-geode/src/main/java/org/springframework/geode/cache/RepositoryCacheWriter.java
@@ -0,0 +1,81 @@
+/*
+ * 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.CacheRuntimeException;
+import org.apache.geode.cache.CacheWriter;
+import org.apache.geode.cache.CacheWriterException;
+import org.apache.geode.cache.EntryEvent;
+import org.apache.geode.cache.RegionEvent;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.geode.cache.support.RepositoryCacheLoaderWriterSupport;
+import org.springframework.geode.core.util.function.FunctionUtils;
+
+/**
+ * A {@link CacheWriter} implementation backed by a Spring Data {@link CrudRepository} used to persist a cache entry
+ * (i.e. entity) to a backend, external data source.
+ *
+ * @author John Blum
+ * @see org.apache.geode.cache.CacheWriter
+ * @see org.springframework.data.repository.CrudRepository
+ * @see org.springframework.geode.cache.support.RepositoryCacheLoaderWriterSupport
+ * @since 1.1.0
+ */
+@SuppressWarnings("unused")
+public class RepositoryCacheWriter<T, ID> extends RepositoryCacheLoaderWriterSupport<T, ID> {
+
+  public RepositoryCacheWriter(CrudRepository<T, ID> repository) {
+    super(repository);
+  }
+
+  @Override
+  public void beforeCreate(EntryEvent<ID, T> event) throws CacheWriterException {
+    doRepositoryOp(event.getNewValue(), getRepository()::save);
+  }
+
+  @Override
+  public void beforeUpdate(EntryEvent<ID, T> event) throws CacheWriterException {
+    doRepositoryOp(event.getNewValue(), getRepository()::save);
+  }
+
+  @Override
+  public void beforeDestroy(EntryEvent<ID, T> event) throws CacheWriterException {
+
+    //doRepositoryOp(event.getOldValue(), FunctionUtils.toNullReturningFunction(getRepository()::delete));
+    doRepositoryOp(event.getKey(), FunctionUtils.toNullReturningFunction(getRepository()::deleteById));
+  }
+
+  @Override
+  public void beforeRegionClear(RegionEvent<ID, T> event) throws CacheWriterException {
+
+    if (isNukeAndPaveEnabled()) {
+      doRepositoryOp(null, FunctionUtils.toNullReturningFunction(it -> getRepository().deleteAll()));
+    }
+  }
+
+  @Override
+  public void beforeRegionDestroy(RegionEvent<ID, T> event) throws CacheWriterException {
+    // TODO: perhaps implement by releasing external data source resources
+    //  (i.e. destroy database object(s), e.g. DROP TABLE)
+  }
+
+  @Override
+  protected CacheRuntimeException newCacheRuntimeException(Supplier<String> messageSupplier, Throwable cause) {
+    return new CacheWriterException(messageSupplier.get(), cause);
+  }
+}