二十、curator recipes之NodeCache

爱被打了一巴掌 2021-12-17 10:59 217阅读 0赞

## 简介  ##

Curator的NodeCache允许你监听一个节点，当节点数据更改或者节点被删除的时候将会触发监听。

官方文档：[http://curator.apache.org/curator-recipes/node-cache.html][http_curator.apache.org_curator-recipes_node-cache.html]

javaDoc：[http://curator.apache.org/apidocs/org/apache/curator/framework/recipes/cache/NodeCache.html][http_curator.apache.org_apidocs_org_apache_curator_framework_recipes_cache_NodeCache.html]

## 代码示例 ##

import org.apache.curator.framework.CuratorFramework;
    import org.apache.curator.framework.CuratorFrameworkFactory;
    import org.apache.curator.framework.recipes.cache.NodeCache;
    import org.apache.curator.retry.ExponentialBackoffRetry;
    
    public class NodeCacheDemo {
        private static CuratorFramework client = CuratorFrameworkFactory.newClient("localhost:2181", new ExponentialBackoffRetry(3000, 1));
        private static String path = "/nodeCache/test/0001";
        static {
            client.start();
        }
    
        public static void main(String[] args) throws Exception {
            if (client.checkExists().forPath(path) == null) {
                System.out.println("not exist");
                client.create().creatingParentsIfNeeded().forPath(path);
            }
            System.out.println("created");
            NodeCache nodeCache = new NodeCache(client, path, false);
            nodeCache.getListenable().addListener(() -> System.out.println("nodeChanged"));
            System.out.println("add listener");
            nodeCache.start(true);
            System.out.println("cache started");
            client.setData().forPath(path, "lay".getBytes());
            System.out.println("set data");
            client.delete().forPath(path);
            System.out.println("deleted");
            Thread.sleep(3000);
            nodeCache.close();
            System.out.println("listener closed");
            Thread.sleep(50000);
            client.close();
        }
    }

转载于:https://www.cnblogs.com/lay2017/p/10280238.html

[http_curator.apache.org_curator-recipes_node-cache.html]: http://curator.apache.org/curator-recipes/node-cache.html
[http_curator.apache.org_apidocs_org_apache_curator_framework_recipes_cache_NodeCache.html]: http://curator.apache.org/apidocs/org/apache/curator/framework/recipes/cache/NodeCache.html