Zookeeper 实现分布式配置管理实现 (一)-CFANZ编程社区

1. zookper 的安装

2. zk_ui 的安装

zkui-2.0-SNAPSHOT-jar-with-dependencies.jar 下载文件，修改配置文件。

主要修改如下：zkServer 的地址

#Server Port
serverPort=9090
#Comma seperated list of all the zookeeper servers
zkServer=172.16.0.4:2181
#Specific roles for ldap authenticated users. Ignore if using file based authentication.
ldapRoleSet={"users": [{ "username":"domain\\user1" , "role": "ADMIN" }]}
userSet = {"users": [{ "username":"admin" , "password":"manager","role": "ADMIN" },{ "username":"appconfig" , "password":"appconfig","role": "USER" }]}
#Set to prod in production and dev in local. Setting to dev will clear history each time.

3. java 代码编写

3.1 mavn 包引用

<dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-recipes</artifactId>
            <version>5.1.0</version>
        </dependency>

3.2 在zookper 创建node 节点

Zookeeper 实现分布式配置管理实现 (一)_apache

3.3 zookper 文件节点读取

pring boot项目的配置文件都是配置在classpath环境变量下面，系统会默认使用ConfigFileApplicationListener去加载；但是如果项目打成war、jar包并且已经升级过了或者在项目之外有自定义的配置文件，这时候想改配置
文件这时候就需要重新打包了，这样很麻烦，而Spring boot也给我们提供了扩展的接口EnvironmentPostProcessor；

如下是实现从 zookeper 中读取配置文件实现，在加载配置文件时，需要添加配置文件。

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.TreeCacheEvent;
import org.apache.curator.framework.recipes.cache.TreeCacheListener;
import org.apache.curator.retry.RetryOneTime;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.env.EnvironmentPostProcessor;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MapPropertySource;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class ZookeeperEnvironmentPostProcessor implements EnvironmentPostProcessor {


    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {

        try {

            System.out.println("获取ev对象，初始化配置");
            String configCenterUrl = environment.getProperty("config.zookeeper.url");
            String configNodename = environment.getProperty("config.zookeeper.nodename");

            CuratorFramework zkClient = CuratorFrameworkFactory.newClient(configCenterUrl,new RetryOneTime(1000));
            zkClient.start();
             // 1. TODO 获取节点下的字节点，下面的每一个子节点都代表一项配置。
            List<String> strings = null;

            Map<String, Object> configMap = new HashMap<>();
            List<String> configNames = zkClient.getChildren().forPath("/"+configNodename);
            for (String configName:configNames) {
                byte[] value = zkClient.getData().forPath("/"+configNodename+"/"+configName);
                configMap.put(configName,new String(value));
                System.out.println(configName+":"+ new String(value));
            }
            // 2  TODO 放到 spring 容器里面
            MapPropertySource propertySource = new MapPropertySource("zkPropertySource",configMap);
            environment.getPropertySources().addFirst(propertySource);

            // 3  TODO 如何动态获取zookper 配置
            TreeCache treeCache = new TreeCache(zkClient,"/"+configNodename);
            treeCache.start();
            treeCache.getListenable().addListener(new TreeCacheListener() {
                @Override
                public void childEvent(CuratorFramework curatorFramework, TreeCacheEvent treeCacheEvent) throws Exception {

                    switch(treeCacheEvent.getType()){
                        case NODE_UPDATED:
                            System.out.println("收到了数据变化通知"+treeCacheEvent.getData());
                            String configName = treeCacheEvent.getData().getPath().replace("/"+configNodename+"/","");
                            String newValue = new String(treeCacheEvent.getData().getData());
                            // TODO  spring 已经创建对象， @value 注入的值如何改变

                            break;
                        default:
                            break;
                    }
                }
            });

        }catch (Exception ex){
           ex.printStackTrace();
        }

    }
}

3.4 在META-INF下创建spring.factories，并且引入 ZookeeperEnvironmentPostProcessor 类

# 告诉 srping boot ，初始化的时候加载我们的自定义拓展
org.springframework.boot.env.EnvironmentPostProcessor=com.hou.zk.demo.config.ZookeeperEnvironmentPostProcessor

3.5 配置项更改通知修改

// 3  TODO 如何动态获取zookper 配置
            TreeCache treeCache = new TreeCache(zkClient,"/"+configNodename);
            treeCache.start();
            treeCache.getListenable().addListener(new TreeCacheListener() {
                @Override
                public void childEvent(CuratorFramework curatorFramework, TreeCacheEvent treeCacheEvent) throws Exception {

                    switch(treeCacheEvent.getType()){
                        case NODE_UPDATED:
                            System.out.println("收到了数据变化通知"+treeCacheEvent.getData());
                            String configName = treeCacheEvent.getData().getPath().replace("/"+configNodename+"/","");
                            String newValue = new String(treeCacheEvent.getData().getData());
                            // TODO  spring 已经创建对象， @value 注入的值如何改变

                            break;
                        default:
                            break;
                    }
                }
            });