{"id":15310,"date":"2023-12-04T17:51:17","date_gmt":"2023-12-04T09:51:17","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=15310"},"modified":"2023-12-16T10:20:42","modified_gmt":"2023-12-16T02:20:42","slug":"zookeeper-zhong-ke-hu-duan-zhu-cewatcher-shi-xian","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/12\/04\/zookeeper-zhong-ke-hu-duan-zhu-cewatcher-shi-xian\/","title":{"rendered":"ZooKeeper\u4e2d\u5ba2\u6237\u7aef\u6ce8\u518cWatcher\u5b9e\u73b0\u8fc7\u7a0b\u8bf4\u4e00\u4e0b\uff1f"},"content":{"rendered":"<p>\u5728ZooKeeper\u4e2d\uff0c\u5ba2\u6237\u7aef\u53ef\u4ee5\u901a\u8fc7\u6ce8\u518cWatcher\u6765\u83b7\u77e5ZooKeeper\u4e2d\u8282\u70b9\u7684\u53d8\u5316\u3002Watcher\u662f\u4e00\u79cd\u4e8b\u4ef6\u901a\u77e5\u673a\u5236\uff0c\u5f53\u8282\u70b9\u7684\u72b6\u6001\u53d1\u751f\u53d8\u5316\u65f6\uff0cZooKeeper\u4f1a\u901a\u77e5\u6ce8\u518c\u4e86Watcher\u7684\u5ba2\u6237\u7aef\u3002\u4e0b\u9762\u662f\u5ba2\u6237\u7aef\u6ce8\u518cWatcher\u7684\u57fa\u672c\u5b9e\u73b0\u8fc7\u7a0b\uff1a<\/p>\n<ol>\n<li>\n<strong>\u521b\u5efaZooKeeper\u5ba2\u6237\u7aef\uff1a<\/strong> \u5ba2\u6237\u7aef\u9996\u5148\u9700\u8981\u521b\u5efa\u4e00\u4e2aZooKeeper\u5bf9\u8c61\uff0c\u8fde\u63a5\u5230ZooKeeper\u670d\u52a1\u5668\u3002\u8fd9\u53ef\u4ee5\u901a\u8fc7ZooKeeper\u6784\u9020\u51fd\u6570\u5b8c\u6210\uff0c\u63d0\u4f9b\u8fde\u63a5\u5b57\u7b26\u4e32\u3001\u4f1a\u8bdd\u8d85\u65f6\u65f6\u95f4\u548c\u4e00\u4e2aWatcher\u5bf9\u8c61\u3002<\/p>\n<pre><code class=\"language-java\">ZooKeeper zk = new ZooKeeper(connectString, sessionTimeout, myWatcher);\n<\/code><\/pre>\n<\/li>\n<li>\n<strong>\u5b9e\u73b0Watcher\u63a5\u53e3\uff1a<\/strong> \u5ba2\u6237\u7aef\u9700\u8981\u5b9e\u73b0<code>Watcher<\/code>\u63a5\u53e3\uff0c\u8be5\u63a5\u53e3\u5b9a\u4e49\u4e86\u4e00\u4e2a\u65b9\u6cd5<code>process<\/code>\uff0c\u7528\u4e8e\u5904\u7406Watcher\u4e8b\u4ef6\u3002\u901a\u5e38\uff0c<code>process<\/code>\u65b9\u6cd5\u4e2d\u5305\u542b\u5ba2\u6237\u7aef\u9700\u8981\u6267\u884c\u7684\u903b\u8f91\uff0c\u4ee5\u54cd\u5e94\u7279\u5b9a\u4e8b\u4ef6\u3002<\/p>\n<pre><code class=\"language-java\">public class MyWatcher implements Watcher {\n    @Override\n    public void process(WatchedEvent event) {\n        \/\/ \u5904\u7406Watcher\u4e8b\u4ef6\u7684\u903b\u8f91\n        System.out.println(&quot;Event type: &quot; + event.getType());\n        System.out.println(&quot;Path: &quot; + event.getPath());\n    }\n}\n<\/code><\/pre>\n<\/li>\n<li>\n<strong>\u6ce8\u518cWatcher\uff1a<\/strong> \u5ba2\u6237\u7aef\u901a\u8fc7<code>exists<\/code>\u3001<code>getData<\/code>\u7b49\u65b9\u6cd5\u5411ZooKeeper\u670d\u52a1\u5668\u6ce8\u518cWatcher\u3002\u8fd9\u6837\uff0c\u5f53\u6307\u5b9a\u8282\u70b9\u7684\u72b6\u6001\u53d1\u751f\u53d8\u5316\u65f6\uff0cWatcher\u5bf9\u8c61\u7684<code>process<\/code>\u65b9\u6cd5\u5c06\u88ab\u8c03\u7528\u3002<\/p>\n<pre><code class=\"language-java\">\/\/ \u6ce8\u518c\u5bf9\u6307\u5b9a\u8282\u70b9\u7684\u6570\u636e\u53d8\u66f4\u4e8b\u4ef6\u7684Watcher\nzk.exists(&quot;\/myNode&quot;, myWatcher);\n\n\/\/ \u6ce8\u518c\u5bf9\u6307\u5b9a\u8282\u70b9\u7684\u5b50\u8282\u70b9\u53d8\u66f4\u4e8b\u4ef6\u7684Watcher\nzk.getChildren(&quot;\/parentNode&quot;, myWatcher);\n<\/code><\/pre>\n<\/li>\n<li>\n<strong>\u5904\u7406Watcher\u4e8b\u4ef6\uff1a<\/strong> \u5f53\u6ce8\u518c\u7684Watcher\u76d1\u6d4b\u5230\u8282\u70b9\u72b6\u6001\u53d8\u5316\u65f6\uff0cZooKeeper\u5c06\u5f02\u6b65\u89e6\u53d1<code>process<\/code>\u65b9\u6cd5\u3002\u5728<code>process<\/code>\u65b9\u6cd5\u4e2d\uff0c\u5ba2\u6237\u7aef\u53ef\u4ee5\u6839\u636e\u4e8b\u4ef6\u7c7b\u578b\u6267\u884c\u76f8\u5e94\u7684\u903b\u8f91\u3002<\/p>\n<pre><code class=\"language-java\">public class MyWatcher implements Watcher {\n    @Override\n    public void process(WatchedEvent event) {\n        \/\/ \u5904\u7406Watcher\u4e8b\u4ef6\u7684\u903b\u8f91\n        System.out.println(&quot;Event type: &quot; + event.getType());\n        System.out.println(&quot;Path: &quot; + event.getPath());\n\n        \/\/ \u6839\u636e\u4e8b\u4ef6\u7c7b\u578b\u6267\u884c\u4e0d\u540c\u7684\u903b\u8f91\n        if (event.getType() == Event.EventType.NodeDataChanged) {\n            \/\/ \u5904\u7406\u8282\u70b9\u6570\u636e\u53d8\u66f4\u4e8b\u4ef6\n            \/\/ ...\n        } else if (event.getType() == Event.EventType.NodeChildrenChanged) {\n            \/\/ \u5904\u7406\u5b50\u8282\u70b9\u53d8\u66f4\u4e8b\u4ef6\n            \/\/ ...\n        }\n    }\n}\n<\/code><\/pre>\n<\/li>\n<\/ol>\n<p>\u901a\u8fc7\u8fd9\u4e2a\u57fa\u672c\u7684\u5b9e\u73b0\u8fc7\u7a0b\uff0cZooKeeper\u5ba2\u6237\u7aef\u53ef\u4ee5\u5728\u9700\u8981\u5173\u6ce8\u8282\u70b9\u72b6\u6001\u53d8\u5316\u7684\u5730\u65b9\u6ce8\u518cWatcher\uff0c\u5e76\u5728\u4e8b\u4ef6\u53d1\u751f\u65f6\u5f97\u5230\u901a\u77e5\uff0c\u4ece\u800c\u5b9e\u73b0\u5bf9ZooKeeper\u4e2d\u8282\u70b9\u72b6\u6001\u53d8\u5316\u7684\u76d1\u63a7\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728ZooKeeper\u4e2d\uff0c\u5ba2\u6237\u7aef\u53ef\u4ee5\u901a\u8fc7\u6ce8\u518cWatcher\u6765\u83b7\u77e5ZooKeeper\u4e2d\u8282\u70b9\u7684\u53d8\u5316\u3002Watcher\u662f [&hellip;]<\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[124],"tags":[],"class_list":["post-15310","post","type-post","status-publish","format-standard","hentry","category-zookeeper"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/15310","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=15310"}],"version-history":[{"count":2,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/15310\/revisions"}],"predecessor-version":[{"id":48353,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/15310\/revisions\/48353"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=15310"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=15310"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=15310"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}