摘要：客戶端鏈接鏈接初始化根據指定的配置名稱獲取對應的配置項根據指定的配置名稱獲取對應的配置項新增或者修改指定的配置刪除指定的配置配置初始化和監聽加載配置啟動監聽線程對某一個配置進行監聽獲取事件變化類型獲取發生變化的獲取變化后的

  
        UTF-8
        UTF-8
        1.8
        1.8
        1.8
  
  
    
      com.coreos
      jetcd-core
      0.0.2
    
    
      org.slf4j
      slf4j-log4j12
      1.7.25
    
    
      log4j
      log4j
      1.2.17
    
    
      org.slf4j
      slf4j-api
      1.7.25
    
    
      org.slf4j
      slf4j-nop
      1.7.25
    
    
      org.slf4j
      slf4j-simple
      1.7.5
    
  
  
    
      
            org.apache.maven.plugins  
            maven-assembly-plugin  
            2.5.5  
              
                  
                      
                        com.xxg.Main  
                      
                  
                  
                    jar-with-dependencies  
                  
              
        
    
  

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客戶端鏈接
    private static Client client = null;
    private static String IPPORT = null;
    static {
        IPPORT = System.getProperty("IPPORT", "http://127.0.0.1:11000");
        getEtcdClient();
    }

    // 鏈接初始化
    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());
            // 啟動監聽線程
            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());
                            // 獲取變化后的value
                            String afterChangeValue = kv.getValue().toStringUtf8();
                        });
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }).start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private String getConfig(List 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;
        }
    }
}