etcd的java客戶端

<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
  </properties>
  <dependencies>
    <dependency>
      <groupId>com.coreos</groupId>
      <artifactId>jetcd-core</artifactId>
      <version>0.0.2</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-log4j12</artifactId>
      <version>1.7.25</version>
    </dependency>
    <dependency>
      <groupId>log4j</groupId>
      <artifactId>log4j</artifactId>
      <version>1.2.17</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>1.7.25</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-nop</artifactId>
      <version>1.7.25</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-simple</artifactId>
      <version>1.7.5</version>
    </dependency>
  </dependencies>
  <build>
    <plugins>
      <plugin>
            <groupId>org.apache.maven.plugins</groupId>  
            <artifactId>maven-assembly-plugin</artifactId>  
            <version>2.5.5</version>  
            <configuration>  
                <archive>  
                    <manifest>  
                        <mainClass>com.xxg.Main</mainClass>  
                    </manifest>  
                </archive>  
                <descriptorRefs>  
                    <descriptorRef>jar-with-dependencies</descriptorRef>  
                </descriptorRefs>  
            </configuration>  
        </plugin>
    </plugins>
  </build>

package com.gemdale.iot;

import com.coreos.jetcd.Client;
import com.coreos.jetcd.KV;
import com.coreos.jetcd.Watch;
import com.coreos.jetcd.data.ByteSequence;
import com.coreos.jetcd.data.KeyValue;

import java.util.List;

public class EtcdUtil1 {
    // etcd客戶端連接
    private static Client client = null;
    private static String IPPORT = null;
    static {
        IPPORT = System.getProperty("IPPORT", "http://127.0.0.1:11000");
        getEtcdClient();
    }

    // 連接初始化
    public static Client getEtcdClient() {
        if (client == null) {
            synchronized (EtcdUtil1.class) {
                client = Client.builder().lazyInitialization(false).endpoints(IPPORT).build();
            }
        }
        return client;
    }

    /**
     * 根據指定的配置名稱獲取對應的value
     * 
     * @param key
     *            配置項
     * @return
     * @throws Exception
     */
    public static String getEtcdValueByKey(String key) throws Exception {
        KeyValue kv = getEtcdKeyValueByKey(key);
        if (kv != null) {
            return kv.getValue().toStringUtf8();
        } else {
            return null;
        }
    }

    /**
     * 根據指定的配置名稱獲取對應的keyvalue
     * 
     * @param key
     *            配置項
     * @return
     * @throws Exception
     */
    public static KeyValue getEtcdKeyValueByKey(String key) throws Exception {
        client.getKVClient().get(ByteSequence.fromString(key)).get().getKvs();
        if (kvs.size() > 0) {
            return kvs.get(0);
        } else {
            return null;
        }
    }

    /**
     * 新增或者修改指定的配置
     * 
     * @param key
     * @param value
     * @return
     */
    public static void putEtcdValueByKey(String key, String value) throws Exception {
        client.getKVClient().put(ByteSequence.fromString(key), ByteSequence.fromBytes(value.getBytes("utf-8")));
    }

    /**
     * 刪除指定的配置
     * 
     * @param key
     * @return
     */
    public static void deleteEtcdValueByKey(String key) {
        client.getKVClient().delete(ByteSequence.fromString(key));
    }

    // V3 api配置初始化和監聽
    public void init() {
        try {
            // 加載配置
            getConfig(client.getKVClient().get(ByteSequence.fromString("test")).get().getKvs());
            // 啓動監聽線程
            new Thread(() -> {
                // 對某一個配置進行監聽
                Watch.Watcher watcher = client.getWatchClient().watch(ByteSequence.fromString("etcd_key"));
                try {
                    while (true) {
                        watcher.listen().getEvents().stream().forEach(watchEvent -> {
                            KeyValue kv = watchEvent.getKeyValue();
                            // 獲取事件變化類型
                            System.out.println(watchEvent.getEventType());
                            // 獲取發生變化的key
                            System.out.println(kv.getKey().toStringUtf8());
                            // 獲取變化後的value
                            String afterChangeValue = kv.getValue().toStringUtf8();
                        });
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }).start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private String getConfig(List<KeyValue> kvs) {
        if (kvs.size() > 0) {
            String config = kvs.get(0).getValue().toStringUtf8();
            System.out.println("etcd 's config 's configValue is :" + config);
            return config;
        } else {
            return null;
        }
    }
}