Github user nickwallen commented on a diff in the pull request:
https://github.com/apache/metron/pull/795#discussion_r146020850
--- Diff:
metron-platform/metron-zookeeper/src/main/java/org/apache/metron/zookeeper/ZKCache.java
---
@@ -0,0 +1,141 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.apache.metron.zookeeper;
+
+import org.apache.curator.RetryPolicy;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.CuratorFrameworkFactory;
+import org.apache.curator.framework.recipes.cache.TreeCache;
+import org.apache.curator.framework.recipes.cache.TreeCacheListener;
+import org.apache.curator.retry.ExponentialBackoffRetry;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.lang.invoke.MethodHandles;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+public class ZKCache implements AutoCloseable{
+ private static final Logger LOG =
LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
+ public static final int DEFAULT_CLIENT_SLEEP_MS = 1000;
+ public static final int DEFAULT_MAX_RETRIES = 3;
+
+
+
+
+ public static class Builder {
+ private Optional<CuratorFramework> client = Optional.empty();
+ private boolean ownClient = false;
+ private List<TreeCacheListener> listener = new ArrayList<>();
+ private String zkRoot;
+
+ public Builder() { }
+
+ public Builder withClient(CuratorFramework client) {
+ this.client = Optional.ofNullable(client);
+ ownClient = false;
+ return this;
+ }
+
+ public Builder withClient(String zookeeperUrl) {
+ this.client = Optional.ofNullable(createClient(zookeeperUrl,
Optional.empty()));
+ ownClient = true;
+ return this;
+ }
+
+ public Builder withClient(String zookeeperUrl, RetryPolicy
retryPolicy) {
+ this.client = Optional.ofNullable(createClient(zookeeperUrl,
Optional.ofNullable(retryPolicy)));
+ ownClient = true;
+ return this;
+ }
+
+ public Builder withListener(TreeCacheListener listener) {
+ this.listener.add(listener);
+ return this;
+ }
+
+ public Builder withRoot(String zkRoot) {
+ this.zkRoot = zkRoot;
+ return this;
+ }
+
+ public ZKCache build() {
+ if(!client.isPresent()) {
+ throw new IllegalArgumentException("Zookeeper client must be
specified.");
+ }
+ if(listener.isEmpty()) {
+ LOG.warn("Zookeeper listener is null or empty, which is very
likely an error.");
+ }
+ if(zkRoot == null) {
+ throw new IllegalArgumentException("Zookeeper root must not be
null.");
+ }
+ return new ZKCache(client.get(), listener, zkRoot, ownClient);
+ }
+
+ }
+
+ private CuratorFramework client;
+ private List<TreeCacheListener> listeners;
+ private TreeCache cache;
+ private String zkRoot;
+ private boolean ownClient = false;
+
+ private ZKCache(CuratorFramework client, List<TreeCacheListener>
listeners, String zkRoot, boolean ownClient) {
--- End diff --
That helps a lot for ZkCache.
Can you do the same for the other new classes? I think that includes
ConfigurationsCache, ConfigurationsUpdater and SimpleEventListener, if I am not
mistaken.
---
