Zookeeper原生Java api使用(四)

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简介: Zookeeper原生Java api使用(四)

zk客户端与服务器连接

客户端和zk服务端链接是一个异步的过程

当连接成功后后,客户端会收的一个watch通知

/**
 * @Title: ZKConnectDemo.java
 * @Description: zookeeper 连接demo演示
 */
public class ZKConnect implements Watcher {
  final static Logger log = LoggerFactory.getLogger(ZKConnect.class);
  public static final String zkServerPath = "192.168.254.130:2181";
//  public static final String zkServerPath = "192.168.1.111:2181,192.168.1.111:2182,192.168.1.111:2183";
  public static final Integer timeout = 5000;
  public static void main(String[] args) throws Exception {
    /**
     * 客户端和zk服务端链接是一个异步的过程
     * 当连接成功后后,客户端会收的一个watch通知
     *
     * 参数:
     * connectString:连接服务器的ip字符串,
     *    比如: "192.168.1.1:2181,192.168.1.2:2181,192.168.1.3:2181"
     *    可以是一个ip,也可以是多个ip,一个ip代表单机,多个ip代表集群
     *    也可以在ip后加路径
     * sessionTimeout:超时时间,心跳收不到了,那就超时
     * watcher:通知事件,如果有对应的事件触发,则会收到一个通知;如果不需要,那就设置为null
     * canBeReadOnly:可读,当这个物理机节点断开后,还是可以读到数据的,只是不能写,
     *                 此时数据被读取到的可能是旧数据,此处建议设置为false,不推荐使用
     * sessionId:会话的id
     * sessionPasswd:会话密码 当会话丢失后,可以依据 sessionId 和 sessionPasswd 重新获取会话
     */
    ZooKeeper zk = new ZooKeeper(zkServerPath, timeout, new ZKConnect());
    log.warn("客户端开始连接zookeeper服务器...");
    log.warn("连接状态:{}", zk.getState());
    new Thread().sleep(2000);
    log.warn("连接状态:{}", zk.getState());
  }
  @Override
  public void process(WatchedEvent event) {
    log.warn("接受到watch通知:{}", event);
  }
}

zk会话重连机制

获取到连接zk的会话id和会话密码,我们就可以再次回到会话中

/**
 * 
 * @Title: ZKConnectDemo.java
 * @Description: zookeeper 恢复之前的会话连接demo演示
 */
public class ZKConnectSessionWatcher implements Watcher {
  final static Logger log = LoggerFactory.getLogger(ZKConnectSessionWatcher.class);
  public static final String zkServerPath = "192.168.254.130:2181";
  public static final Integer timeout = 5000;
  public static void main(String[] args) throws Exception {
    ZooKeeper zk = new ZooKeeper(zkServerPath, timeout, new ZKConnectSessionWatcher());
    new Thread().sleep(1000);
    long sessionId = zk.getSessionId();
    String ssid = "0x" + Long.toHexString(sessionId);
    System.out.println(ssid);
    byte[] sessionPassword = zk.getSessionPasswd();
    log.warn("客户端开始连接zookeeper服务器...");
    log.warn("连接状态:{}", zk.getState());
    log.warn("连接状态:{}", zk.getState());
    new Thread().sleep(200);
    // 开始会话重连
    log.warn("开始会话重连...");
    ZooKeeper zkSession = new ZooKeeper(zkServerPath, 
                      timeout, 
                      new ZKConnectSessionWatcher(), 
                      sessionId, 
                      sessionPassword);
    log.warn("重新连接状态zkSession:{}", zkSession.getState());
    new Thread().sleep(1000);
    log.warn("重新连接状态zkSession:{}", zkSession.getState());
  }
  @Override
  public void process(WatchedEvent event) {
    log.warn("接受到watch通知:{}", event);
  }
}

java操作zk,节点的创建,删除,设置

/**
 * 
 * @Title: ZKConnectDemo.java
 * @Description: zookeeper 操作demo演示
 */
public class ZKNodeOperator implements Watcher {
  private ZooKeeper zookeeper = null;
  public static final String zkServerPath = "192.168.254.130:2181";
  public static final Integer timeout = 5000;
  public ZKNodeOperator() {}
  public ZKNodeOperator(String connectString) {
    try {
      zookeeper = new ZooKeeper(connectString, timeout, new ZKNodeOperator());
    } catch (IOException e) {
      e.printStackTrace();
      if (zookeeper != null) {
        try {
          zookeeper.close();
        } catch (InterruptedException e1) {
          e1.printStackTrace();
        }
      }
    }
  }
  /**
   * 
   * @Title: ZKOperatorDemo.java
   * @Description: 创建zk节点
   */
  public void createZKNode(String path, byte[] data, List<ACL> acls) {
    String result = "";
    try {
      /**
       * 同步或者异步创建节点,都不支持子节点的递归创建,异步有一个callback函数
       * 参数:
       * path:创建的路径
       * data:存储的数据的byte[]
       * acl:控制权限策略
       *      Ids.OPEN_ACL_UNSAFE --> world:anyone:cdrwa
       *      CREATOR_ALL_ACL --> auth:user:password:cdrwa
       * createMode:节点类型, 是一个枚举
       *      PERSISTENT:持久节点
       *      PERSISTENT_SEQUENTIAL:持久顺序节点
       *      EPHEMERAL:临时节点
       *      EPHEMERAL_SEQUENTIAL:临时顺序节点
       */
      result = zookeeper.create(path, data, acls, CreateMode.PERSISTENT);
      //异步创建,CreateCallBack是一个回调函数
/*      String ctx = "{'create':'success'}";
      zookeeper.create(path, data, acls, CreateMode.PERSISTENT, new CreateCallBack(), ctx);*/
      System.out.println("创建节点:\t" + result + "\t成功...");
      new Thread().sleep(2000);
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
  public static void main(String[] args) throws Exception {
    ZKNodeOperator zkServer = new ZKNodeOperator(zkServerPath);
    // 创建zk节点
    zkServer.createZKNode("/testnode", "testnode".getBytes(), Ids.OPEN_ACL_UNSAFE);
    /**
     * 设置节点数据
     * 参数:
     * path:节点路径
     * data:数据
     * version:数据状态
     */
//    Stat status  = zkServer.getZookeeper().setData("/testnode", "xyz".getBytes(), 2);
//    System.out.println(status.getVersion());
    /**
     * 同步删除数据,没有返回数据
     * 参数:
     * path:节点路径
     * version:数据状态
     */
/*    zkServer.createZKNode("/test-delete-node", "123".getBytes(), Ids.OPEN_ACL_UNSAFE);
    zkServer.getZookeeper().delete("/test-delete-node", 2);
    /**
     * 异步删除数据,在回调函数里面返回
     * 参数:
     * path:节点路径
     * version:数据状态
     */
    String ctx = "{'delete':'success'}";
    zkServer.getZookeeper().delete("/test-delete-node", 0, new DeleteCallBack(), ctx);
    Thread.sleep(2000);*/
  }
  public ZooKeeper getZookeeper() {
    return zookeeper;
  }
  public void setZookeeper(ZooKeeper zookeeper) {
    this.zookeeper = zookeeper;
  }
  @Override
  public void process(WatchedEvent event) {
  }
}

删除回调函数

public class DeleteCallBack implements VoidCallback {
  @Override
  public void processResult(int rc, String path, Object ctx) {
    System.out.println("删除节点" + path);
    System.out.println((String)ctx);
  }
}

获取zk节点数据

使用CountDownLatch来监听

public class ZKGetNodeData implements Watcher {
  private ZooKeeper zookeeper = null;
  public static final String zkServerPath = "192.168.254.130:2181";
  public static final Integer timeout = 5000;
  //存放节点数据
  private static Stat stat = new Stat();
  public ZKGetNodeData() {}
  public ZKGetNodeData(String connectString) {
    try {
      zookeeper = new ZooKeeper(connectString, timeout, new ZKGetNodeData());
    } catch (IOException e) {
      e.printStackTrace();
      if (zookeeper != null) {
        try {
          zookeeper.close();
        } catch (InterruptedException e1) {
          e1.printStackTrace();
        }
      }
    }
  }
  private static CountDownLatch countDown = new CountDownLatch(1);
  public static void main(String[] args) throws Exception {
    ZKGetNodeData zkServer = new ZKGetNodeData(zkServerPath);
    /**
     * 参数:
     * path:节点路径
     * watch:true或者false,注册一个watch事件
     * stat:状态
     */
    byte[] resByte = zkServer.getZookeeper().getData("/bushro", true, stat);
    String result = new String(resByte);
    System.out.println("当前值:" + result);
    countDown.await();
  }
  @Override
  public void process(WatchedEvent event) {
    try {
      if(event.getType() == EventType.NodeDataChanged){
        ZKGetNodeData zkServer = new ZKGetNodeData(zkServerPath);
        byte[] resByte = zkServer.getZookeeper().getData("/bushro", false, stat);
        String result = new String(resByte);
        System.out.println("更改后的值:" + result);
        System.out.println("版本号变化dversion:" + stat.getVersion());
        countDown.countDown();
      } else if(event.getType() == EventType.NodeCreated) {
      } else if(event.getType() == EventType.NodeChildrenChanged) {
      } else if(event.getType() == EventType.NodeDeleted) {
      } 
    } catch (KeeperException e) { 
      e.printStackTrace();
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
  }
  public ZooKeeper getZookeeper() {
    return zookeeper;
  }
  public void setZookeeper(ZooKeeper zookeeper) {
    this.zookeeper = zookeeper;
  }
}

获取zk子节点列表

public class ZKGetChildrenList implements Watcher {
  private ZooKeeper zookeeper = null;
  public static final String zkServerPath = "192.168.254.130:2181";
  public static final Integer timeout = 5000;
  public ZKGetChildrenList() {}
  public ZKGetChildrenList(String connectString) {
    try {
      zookeeper = new ZooKeeper(connectString, timeout, new ZKGetChildrenList());
    } catch (IOException e) {
      e.printStackTrace();
      if (zookeeper != null) {
        try {
          zookeeper.close();
        } catch (InterruptedException e1) {
          e1.printStackTrace();
        }
      }
    }
  }
  private static CountDownLatch countDown = new CountDownLatch(1);
  public static void main(String[] args) throws Exception {
    ZKGetChildrenList zkServer = new ZKGetChildrenList(zkServerPath);
    /**
     * 参数:
     * path:父节点路径
     * watch:true或者false,注册一个watch事件
     */
//    List<String> strChildList = zkServer.getZookeeper().getChildren("/bushro", true);
//    for (String s : strChildList) {
//      System.out.println(s);
//    }
    // 异步调用
    String ctx = "{'callback':'ChildrenCallback'}";
    //回调函数一个是有返回子节点信息(Children2CallBack),一个没有(ChildrenCallBack)
//    zkServer.getZookeeper().getChildren("/imooc", true, new ChildrenCallBack(), ctx);
    zkServer.getZookeeper().getChildren("/bushro", true, new Children2CallBack(), ctx);
    countDown.await();
  }
  @Override
  public void process(WatchedEvent event) {
    try {
      if(event.getType()==EventType.NodeChildrenChanged){
        System.out.println("NodeChildrenChanged");
        ZKGetChildrenList zkServer = new ZKGetChildrenList(zkServerPath);
        List<String> strChildList = zkServer.getZookeeper().getChildren(event.getPath(), false);
        for (String s : strChildList) {
          System.out.println("子节点: "+s);
        }
        countDown.countDown();
      } else if(event.getType() == EventType.NodeCreated) {
        System.out.println("NodeCreated");
      } else if(event.getType() == EventType.NodeDataChanged) {
        System.out.println("NodeDataChanged");
      } else if(event.getType() == EventType.NodeDeleted) {
        System.out.println("NodeDeleted");
      } 
    } catch (KeeperException e) {
      e.printStackTrace();
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
  }
  public ZooKeeper getZookeeper() {
    return zookeeper;
  }
  public void setZookeeper(ZooKeeper zookeeper) {
    this.zookeeper = zookeeper;
  }
}

回调函数

public class Children2CallBack implements Children2Callback {
  @Override
  public void processResult(int rc, String path, Object ctx, List<String> children, Stat stat) {
    for (String s : children) {
      System.out.println(s);
    }
    System.out.println("ChildrenCallback:" + path);
    System.out.println((String)ctx);  
    System.out.println("czxid:"+stat.getCzxid());
    System.out.println("ctime:"+stat.getCtime());
    System.out.println("mzxid:"+stat.getMzxid());
    System.out.println("mtime:"+stat.getMtime());
    System.out.println("pzxid:"+stat.getPzxid());
    System.out.println("cversion:"+stat.getCversion());
    System.out.println("version:"+stat.getVersion());
    System.out.println("ephemeralOwner:"+stat.getEphemeralOwner());
    System.out.println("numChildren:"+stat.getNumChildren());
  }
}

删除子节点后触发的事件

20190721131838665.png

判断节否存在

public class ZKNodeExist implements Watcher {
  private ZooKeeper zookeeper = null;
  public static final String zkServerPath = "192.168.254.130:2181";
  public static final Integer timeout = 5000;
  public ZKNodeExist() {}
  public ZKNodeExist(String connectString) {
    try {
      zookeeper = new ZooKeeper(connectString, timeout, new ZKNodeExist());
    } catch (IOException e) {
      e.printStackTrace();
      if (zookeeper != null) {
        try {
          zookeeper.close();
        } catch (InterruptedException e1) {
          e1.printStackTrace();
        }
      }
    }
  }
  private static CountDownLatch countDown = new CountDownLatch(1);
  public static void main(String[] args) throws Exception {
    ZKNodeExist zkServer = new ZKNodeExist(zkServerPath);
    /**
     * 参数:
     * path:节点路径
     * watch:watch
     */
    Stat stat = zkServer.getZookeeper().exists("/bushro", true);
    if (stat != null) {
      System.out.println("查询的节点版本为dataVersion:" + stat.getVersion());
    } else {
      System.out.println("该节点不存在...");
    }
    countDown.await();
  }
  @Override
  public void process(WatchedEvent event) {
    if (event.getType() == EventType.NodeCreated) {
      System.out.println("节点创建");
      countDown.countDown();
    } else if (event.getType() == EventType.NodeDataChanged) {
      System.out.println("节点数据改变");
      countDown.countDown();
    } else if (event.getType() == EventType.NodeDeleted) {
      System.out.println("节点删除");
      countDown.countDown();
    }
  }
  public ZooKeeper getZookeeper() {
    return zookeeper;
  }
  public void setZookeeper(ZooKeeper zookeeper) {
    this.zookeeper = zookeeper;
  }
}

Acl相关操作

public class ZKNodeAcl implements Watcher {
  private ZooKeeper zookeeper = null;
  public static final String zkServerPath = "192.168.254.130:2181";
  public static final Integer timeout = 5000;
  public ZKNodeAcl() {}
  public ZKNodeAcl(String connectString) {
    try {
      zookeeper = new ZooKeeper(connectString, timeout, new ZKNodeAcl());
    } catch (IOException e) {
      e.printStackTrace();
      if (zookeeper != null) {
        try {
          zookeeper.close();
        } catch (InterruptedException e1) {
          e1.printStackTrace();
        }
      }
    }
  }
  public void createZKNode(String path, byte[] data, List<ACL> acls) {
    String result = "";
    try {
      /**
       * 同步或者异步创建节点,都不支持子节点的递归创建,异步有一个callback函数
       * 参数:
       * path:创建的路径
       * data:存储的数据的byte[]
       * acl:控制权限策略
       *      Ids.OPEN_ACL_UNSAFE --> world:anyone:cdrwa
       *      CREATOR_ALL_ACL --> auth:user:password:cdrwa
       * createMode:节点类型, 是一个枚举
       *      PERSISTENT:持久节点
       *      PERSISTENT_SEQUENTIAL:持久顺序节点
       *      EPHEMERAL:临时节点
       *      EPHEMERAL_SEQUENTIAL:临时顺序节点
       */
      result = zookeeper.create(path, data, acls, CreateMode.PERSISTENT);
      System.out.println("创建节点:\t" + result + "\t成功...");
    } catch (KeeperException e) {
      e.printStackTrace();
    } catch (InterruptedException e) {
      e.printStackTrace();
    } 
  }
  public static void main(String[] args) throws Exception {
    ZKNodeAcl zkServer = new ZKNodeAcl(zkServerPath);
    /**
     * ======================  创建node start  ======================  
     */
    //acl 任何人都可以访问
    zkServer.createZKNode("/aclbushro", "test".getBytes(), Ids.OPEN_ACL_UNSAFE);
    //(测试1)自定义用户认证访问
    List<ACL> acls = new ArrayList<ACL>();
    Id bushro1 = new Id("digest", AclUtils.getDigestUserPwd("bushro1:123456"));
    Id bushro2 = new Id("digest", AclUtils.getDigestUserPwd("bushro2:123456"));
    //设置用户以及对应的权限
    acls.add(new ACL(Perms.ALL, bushro1));
    acls.add(new ACL(Perms.READ, bushro2));
    acls.add(new ACL(Perms.DELETE | Perms.CREATE, bushro2));
    zkServer.createZKNode("/aclbushro/testdigest", "testdigest".getBytes(), acls);
    //注册过的用户必须通过addAuthInfo才能操作节点,参考命令行 addauth
    zkServer.getZookeeper().addAuthInfo("digest", "bushro1:123456".getBytes());
    zkServer.createZKNode("/aclbushro/testdigest/childtest", "childtest".getBytes(), Ids.CREATOR_ALL_ACL);
    Stat stat = new Stat();
    byte[] data = zkServer.getZookeeper().getData("/aclbushro/testdigest", false, stat);
    System.out.println(new String(data));
    zkServer.getZookeeper().setData("/aclbushro/testdigest", "now".getBytes(), 1);
    //(测试二)ip方式的acl
    List<ACL> aclsIP = new ArrayList<ACL>();
    Id ipId1 = new Id("ip", "192.168.1.6");
    aclsIP.add(new ACL(Perms.ALL, ipId1));
    zkServer.createZKNode("/aclbushro/iptest6", "iptest".getBytes(), aclsIP);
    //验证ip是否有权限
    zkServer.getZookeeper().setData("/aclbushro/iptest6", "now".getBytes(), 1);
    Stat stat = new Stat();
    byte[] data = zkServer.getZookeeper().getData("/aclbushro/iptest6", false, stat);
    System.out.println(new String(data));
    System.out.println(stat.getVersion());
  }
  public ZooKeeper getZookeeper() {
    return zookeeper;
  }
  public void setZookeeper(ZooKeeper zookeeper) {
    this.zookeeper = zookeeper;
  }
  @Override
  public void process(WatchedEvent event) {
  }
}

20190721134148459.png

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随着电子商务的蓬勃发展,企业为了扩大市场覆盖面,经常需要在多个在线平台上展示和销售产品。然而,手工管理多个平台的库存、价格、商品描述等信息既耗时又容易出错。商品API接口在这一背景下显得尤为重要,它能够帮助企业在不同的销售平台之间实现商品信息的高效同步和管理。本文将通过具体的淘宝API接口使用案例,展示如何在跨平台销售中有效利用商品API接口,以及如何通过代码实现数据的统一管理。