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
