etcd简单测试类java版

为了方便现场安装完了etcd集群后确认集群是否好用，简单写了个测试类，网上搜的有点乱还有些不能运行，在这里再整理一个能够直接运行的

1、我把etcd的API设成3版本了，调用使用的jetcd，功能挺多，这里只用了最简单的数据增删查操作，再Maven配置文件中增加依赖

        <dependency>
            <groupId>io.etcd</groupId>
            <artifactId>jetcd-core</artifactId>
            <version>0.3.0</version>
        </dependency>

2、直接贴代码了，代码很简单没什么好解释的，要想用复杂功能还需要再去研究jetcd的各种API了

/**
 * 
 */
package com.zyh.etcd;

import static com.google.common.base.Charsets.UTF_8;

import java.util.Optional;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;

import io.etcd.jetcd.ByteSequence;
import io.etcd.jetcd.Client;
import io.etcd.jetcd.Watch.Watcher;
import io.etcd.jetcd.kv.GetResponse;
import io.etcd.jetcd.options.GetOption;
import io.etcd.jetcd.options.WatchOption;
import io.etcd.jetcd.watch.WatchEvent;

/**
 * etcd 操作工具，包括启动监听和操作etcd v3 版本协议，只测试功能，未添加log
 * 
 * @version 1.0
 * @author zhangyanhua
 * @date 2019年10月29日 下午4:30:57
 */
public class EtcdUtil
{
    // etcl客户端链接
    private static Client etcdClient = null;

    // 链接初始化
    public static synchronized Client getEtclClient()
    {
        if (etcdClient == null)
        {
            //String[] urls = PropertiesUtil.getValue("etcd_node_url").split(",");
            String[] urls = "http://10.110.30.210:2379,http://10.110.30.212:2379,http://10.110.30.213:2379".split(",");
            etcdClient = Client.builder().endpoints(urls).build();
        }
        return etcdClient;
    }

    /**
     * 新增或者修改指定的配置
     * 
     * @param key
     * @param value
     * @throws Exception
     * @author zhangyanhua
     * @date 2019年10月29日 下午4:41:06
     */
    public static void putEtcdValueByKey(String key, String value) throws Exception
    {
        Client client = EtcdUtil.getEtclClient();
        client.getKVClient().put(ByteSequence.from(key, UTF_8), ByteSequence.from(value, UTF_8)).get();
        //System.out.println("put etcd key:value "" + key + ":" + value + "" success");
        client.close();
        etcdClient = null;
    }

    /**
     * 查询指定的key名称对应的value
     * 
     * @param key
     * @return value值
     * @throws Exception
     * @author zhangyanhua
     * @date 2019年10月29日 下午4:35:44
     */
    public static String getEtcdValueByKey(String key) throws Exception
    {
        Client client = EtcdUtil.getEtclClient();
        GetResponse getResponse = client.getKVClient()
                .get(ByteSequence.from(key, UTF_8), GetOption.newBuilder().build()).get();
        client.close();
        etcdClient = null;

        // key does not exist
        if (getResponse.getKvs().isEmpty())
        {
            return null;
        }

        return getResponse.getKvs().get(0).getValue().toString(UTF_8);
    }

    /**
     * 删除指定的配置
     * 
     * @param key
     * @throws InterruptedException
     * @throws ExecutionException
     * @author zhangyanhua
     * @date 2019年10月29日 下午4:53:24
     */
    public static void deleteEtcdValueByKey(String key) throws InterruptedException, ExecutionException
    {
        Client client = EtcdUtil.getEtclClient();
        client.getKVClient().delete(ByteSequence.from(key, UTF_8)).get();
        //System.out.println("delete etcd key "" + key + "" success");
        client.close();
        etcdClient = null;
    }

    /**
     * 持续监控某个key变化的方法，执行后如果key有变化会被监控到，输入结果如下
     *  watch type= "PUT", key= "zyh1", value= "zyh1-value" 
     *  watch type= "PUT", key= "zyh1", value= "zyh1-value111" 
     *  watch type= "DELETE", key= "zyh1", value= ""
     * 
     * @param key
     * @throws Exception
     * @author zhangyanhua
     * @date 2019年10月29日 下午5:26:09
     */
    public static void watchEtcdKey(String key) throws Exception
    {
        Client client = EtcdUtil.getEtclClient();
        // 最大事件数量
        Integer maxEvents = Integer.MAX_VALUE;
        CountDownLatch latch = new CountDownLatch(maxEvents);
        Watcher watcher = null;
        try
        {
            ByteSequence watchKey = ByteSequence.from(key, UTF_8);
            WatchOption watchOpts = WatchOption.newBuilder().build();

            watcher = client.getWatchClient().watch(watchKey, watchOpts, response -> {
                for (WatchEvent event : response.getEvents())
                {
                    System.out.println("watch type= "" + event.getEventType().toString() + "",  key= ""
                            + Optional.ofNullable(event.getKeyValue().getKey()).map(bs -> bs.toString(UTF_8)).orElse("")
                            + "",  value= "" + Optional.ofNullable(event.getKeyValue().getValue())
                                    .map(bs -> bs.toString(UTF_8)).orElse("")
                            + """);
                }

                latch.countDown();
            });

            latch.await();
        }
        catch (Exception e)
        {
            if (watcher != null)
            {
                watcher.close();
                client.close();
                etcdClient = null;
            }
            throw e;
        }
    }

    /**
     * TODO
     * 
     * @param args
     * @throws Exception
     * @author zhangyanhua
     * @date 2019年10月29日 下午6:01:54
     */
    public static void main(String[] args) throws Exception
    {
        boolean success = true;

        String key = "zyh";
        String value = "zyh-value";
        String newValue = "zyh-value-new";

        System.out.println("**** 测试方法开始 ****");
        EtcdUtil.putEtcdValueByKey(key, value);
        String retValue = EtcdUtil.getEtcdValueByKey(key);
        // System.out.println("查询key " + key + " 对应的值是 " + retValue);
        if (value.equals(retValue))
        {
            System.out.println("数据插入成功。");
            System.out.println("数据查询成功。");
        }
        else
        {
            success = false;
            System.out.println("数据插入或查询失败！");
        }

        EtcdUtil.putEtcdValueByKey(key, newValue);
        retValue = EtcdUtil.getEtcdValueByKey(key);
        // System.out.println("查询key " + key + " 对应的值是 " + retValue);
        if (newValue.equals(retValue))
        {
            System.out.println("数据更新成功。");
        }
        else
        {
            success = false;
            System.out.println("数据更新失败！");
        }

        EtcdUtil.deleteEtcdValueByKey(key);
        retValue = EtcdUtil.getEtcdValueByKey(key);
        // System.out.println("查询key " + key + " 对应的值是 " + retValue);
        if (retValue == null)
        {
            System.out.println("数据删除成功。");
        }
        else
        {
            success = false;
            System.out.println("数据删除失败！");
        }

        // EtcdUtil.watchEtcdKey(key);

        if (success)
        {
            System.out.println("**** 测试方法全部通过。 ****");
        }
        else
        {
            System.out.println("**** 测试失败！ ****");
        }
    }
}

上面代码运行结果如下

还有个监控数据的watchEtcdKey方法没有执行，这个执行后代码是一直运行的，持续监控想要监控的数据，当数据出现变化事可以获取变化的事件，例如这样

在后台操作一组数据

 监控端可以检测到数据变化