09. Zookeeper JavaAPI-常用操作

灰太狼 2022-03-18 02:28 267阅读 0赞

> Zookeeper 的JavaAPI对常用的节点操作都进行了封装, 和Shell 提供的命令差不多.

## 1. 创建节点API ##

### 1.1 创建默认权限节点 ###

zooKeeper.create("/node-anyone", "test node anyone".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);

### 1.2 创建auth 权限模式节点 ###

// 添加用户认证信息
    zooKeeper.addAuthInfo("digest", "admin:admin".getBytes());
    zooKeeper.addAuthInfo("digest", "admin:123456".getBytes());
    
    // 创建节点
    zooKeeper.create("/node-auth", "test node auth".getBytes(), ZooDefs.Ids.CREATOR_ALL_ACL, CreateMode.PERSISTENT);

### 1.3 创建digest 模式权限节点 ###

// 权限位使用或运算符拼接
    int aclVal = ZooDefs.Perms.CREATE | ZooDefs.Perms.DELETE | ZooDefs.Perms.READ | ZooDefs.Perms.WRITE;
    
    // 生成加密的用户认证信息
    String authentication = DigestAuthenticationProvider.generateDigest("admin:admin");
    
    // 创建权限模式
    ACL acl = new ACL(aclVal, new Id("digest", authentication));
    
    // 创建节点
    zooKeeper.create("/node-digest", "test node auth".getBytes(), Collections.singletonList(acl), CreateMode.PERSISTENT);

### 1.4 创建短暂有序节点 ###

// 创建节点, 返回节点名称. 因为有序, 所以节点名称和指定名称不同
    String nodeName = zooKeeper.create("/node-es", "test node anyone".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
    System.out.println("nodeName:" + nodeName);

## 2. 节点操作API ##

### 2.1 获取节点数据 ###

// 用于保存节点信息
    Stat stat = new Stat();
    
    // 获取节点数据
    byte[] data = zooKeeper.getData("/node-anyone", false, stat);
    System.out.println("data:" + new String(data));
    System.out.println("stat.version:" + stat.getVersion());

### 2.2 获取子节点 ###

List<String> children = zooKeeper.getChildren("/", false);

### 2.3 判断节点是否存在 ###

Stat stat = zooKeeper.exists("/sss", false);

### 2.4 删除节点 ###

删除节点时, 必须指定节点版本号.

// 获取节点状态
    Stat stat = new Stat();
    zooKeeper.getData("/test", false, stat);
    
    // 删除节点
    zooKeeper.delete("/test", stat.getVersion());

## 3. 权限操作API ##

### 3.1 获取权限 ###

List<ACL> aclList = zooKeeper.getACL("/node-auth", new Stat());

### 3.2 设置权限 ###

设置权限时, 需要指定节点版本号.

// 创建节点信息对象, 用于保存节点信息
    Stat nodeStat = new Stat();
    zooKeeper.getData(nodePath, false, nodeStat);
    
    // 更新节点权限
    zooKeeper.setACL("/node-auth", ZooDefs.Ids.READ_ACL_UNSAFE, nodeStat.getVersion());

## 4. 批量操作 ##

zookeeper 提供了multi() 和 transaction()API 来进行批量操作. 而Transaction 对象其实就是将multi 进行了一层封装而已.

//批量操作
    List<Op> opList = new ArrayList<>();
    opList.add(Op.create("/nodes", "nodes".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
    opList.add(Op.create("/nodes/A", "aa".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
    opList.add(Op.create("/nodes/B", "bb".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
    opList.add(Op.create("/nodes/C", "cc".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
    // 如果添加此行, 则全部失败
    // opList.add(Op.create("/nodes/D/dd", "dd".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
    
    
    List<OpResult> multi = zooKeeper.multi(opList);
    for (OpResult opResult : multi) { 
    
    }
    multi.stream()
            .map(opResult -> (OpResult.CreateResult) opResult)
            .forEach(result -> System.out.println(result.getPath() + "-> " + result.getType()));

## 5. 完整测试用例 ##

import org.apache.zookeeper.*;
    import org.apache.zookeeper.data.ACL;
    import org.apache.zookeeper.data.Id;
    import org.apache.zookeeper.data.Stat;
    import org.apache.zookeeper.server.auth.DigestAuthenticationProvider;
    import org.junit.BeforeClass;
    import org.junit.Test;
    
    import java.security.NoSuchAlgorithmException;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.List;
    
    /** * @Description: 测试同步API * @author: zongf * @date: 2019-02-17 10:20 */
    public class TestAPI { 
    
        // zookeeper 地址, 多个地址以逗号割开
        private static String zkServer = "127.0.0.1:2181,127.0.0.1:2182,127.0.0.1:2183";
    
        // 会话超时时间
        private static int sessionTimeout = 3000;
    
        // zookeeper 客户端连接
        private static ZooKeeper zooKeeper;
    
        @BeforeClass
        public static void init() throws Exception{ 
            zooKeeper = new ZooKeeper(zkServer, sessionTimeout, watchedEvent ->{ });
            System.out.println("******************* init start ***********************");
            System.out.println("state:" + zooKeeper.getState());
            System.out.println("sessionPwd:" + zooKeeper.getSessionPasswd());
            System.out.println("sessionId:" + zooKeeper.getSessionId());
            System.out.println("timeout:" + zooKeeper.getSessionTimeout());
    
            System.out.println("******************* init end ***********************");
        }
    
    
        // 创建shell默认模式节点, 访问权限为- world:anyone:cdrwa
        @Test
        public void create_world() throws KeeperException, InterruptedException{ 
            // 创建节点
            zooKeeper.create("/node-anyone", "test node anyone".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        }
    
        // 创建auth权限模式节点, 访问权限为- auth::cdrwa
        @Test
        public void create_auth() throws KeeperException, InterruptedException{ 
            // 添加用户认证信息
            zooKeeper.addAuthInfo("digest", "admin:admin".getBytes());
            zooKeeper.addAuthInfo("digest", "admin:123456".getBytes());
    
            // 创建节点
            zooKeeper.create("/node-auth", "test node auth".getBytes(), ZooDefs.Ids.CREATOR_ALL_ACL, CreateMode.PERSISTENT);
        }
    
        // 创建digest模式节点, 访问权限为: cdrw, 只能admin用户访问
        @Test
        public void cteate_digest() throws KeeperException, InterruptedException, NoSuchAlgorithmException { 
    
            // 权限位使用或运算符拼接
            int aclVal = ZooDefs.Perms.CREATE | ZooDefs.Perms.DELETE | ZooDefs.Perms.READ | ZooDefs.Perms.WRITE;
    
            // 生成加密的用户认证信息
            String authentication = DigestAuthenticationProvider.generateDigest("admin:admin");
    
            // 创建权限模式
            ACL acl = new ACL(aclVal, new Id("digest", authentication));
    
            // 创建节点
            zooKeeper.create("/node-digest", "test node auth".getBytes(), Collections.singletonList(acl), CreateMode.PERSISTENT);
        }
    
        // 创建短暂有序节点
        @Test
        public void create_ephemeral_sequential() throws KeeperException, InterruptedException{ 
            // 创建节点, 返回节点名称. 因为有序, 所以节点名称和指定名称不同
            String nodeName = zooKeeper.create("/node-es", "test node anyone".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
            System.out.println("nodeName:" + nodeName);
    
            // 休眠线程, 否则会话结束短暂节点就销毁了
            Thread.sleep(10000);
        }
    
    
        // 异步创建
        @Test
        public void create_ansy() throws KeeperException, InterruptedException { 
            zooKeeper.create("/learn2", "just for learn async".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT_SEQUENTIAL, new AsyncCallback.StringCallback() { 
                @Override
                public void processResult(int rc, String path, Object ctx, String name) { 
                    System.out.println("rc:" + rc);
                    System.out.println("path:" + path);
                    System.out.println("name:" + name);
                    System.out.println("ctx:" + ctx);
                }
            }, "回调结果");
    
            Thread.sleep(2000);
        }
    
        // 获取节点数据 和 状态
        @Test
        public void test_getData() throws KeeperException, InterruptedException { 
    
            // 用于保存节点信息
            Stat stat = new Stat();
    
            // 获取节点数据
            byte[] data = zooKeeper.getData("/node-anyone", false, stat);
            System.out.println("data:" + new String(data));
            System.out.println("stat.version:" + stat.getVersion());
        }
    
        @Test
        public void test_getChildren() throws KeeperException, InterruptedException { 
            List<String> children = zooKeeper.getChildren("/", false);
            System.out.println(children);
        }
    
        // 测试节点是否存在
        @Test
        public void test_exsists() throws KeeperException, InterruptedException { 
            Stat stat = zooKeeper.exists("/sss", false);
            System.out.println(stat != null? stat : "/sss节点不存在" );
        }
    
        // 删除节点: 必须指定版本号, 只能删除空节点. 不支持shell的rmr 操作
        @Test
        public void test_delete() throws KeeperException, InterruptedException { 
            // 创建测试节点
            zooKeeper.create("/test", "test delete".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    
            // 获取节点状态
            Stat stat = new Stat();
            zooKeeper.getData("/test", false, stat);
    
            // 删除节点
            zooKeeper.delete("/test", stat.getVersion());
    
        }
    
    
    
        // 获取权限
        @Test
        public void test_getACL() throws KeeperException, InterruptedException { 
            Stat nodeStat = new Stat();
            List<ACL> aclList = zooKeeper.getACL("/node-auth", nodeStat);
            aclList.forEach(acl  -> System.out.println(acl.getId().toString().trim() + "->" + convertPerms(acl.getPerms())));
        }
    
        // 更新权限
        @Test
        public void test_setACL() throws KeeperException, InterruptedException { 
            String nodePath = "/node-anyone";
    
            // 首先认证用户
            zooKeeper.addAuthInfo("digest", "admin:123456".getBytes());
    
            // 输出节点权限
            List<ACL> aclList = zooKeeper.getACL(nodePath, new Stat());
            aclList.forEach(acl  -> System.out.println(acl.getId().toString().trim() + "->" + convertPerms(acl.getPerms())));
    
            // 创建节点信息对象, 用于保存节点信息
            Stat nodeStat = new Stat();
            zooKeeper.getData(nodePath, false, nodeStat);
    
            // 更新节点权限
            zooKeeper.setACL("/node-auth", ZooDefs.Ids.READ_ACL_UNSAFE, nodeStat.getVersion());
    
            System.out.println("修改后:");
    
            // 重新输出节点权限
            List<ACL> aclListAfter = zooKeeper.getACL(nodePath, new Stat());
            aclListAfter.forEach(acl  -> System.out.println(acl.getId().toString().trim() + "->" + convertPerms(acl.getPerms())));
    
    // 输出结果
    // 'digest,'admin:0uek/hZ/V9fgiM35b0Z2226acMQ=->rwcda
    // 'digest,'admin:x1nq8J5GOJVPY6zgzhtTtA9izLc=->rwcda
    // 修改后:
    // 'world,' anyone -> r
    
        }
    
        // 将权限位转换为shell 字母
        public static String convertPerms(int perms) { 
    
            if (perms == ZooDefs.Perms.ALL) { 
                return "rwcda";
            }
    
            StringBuffer sb = new StringBuffer();
    
            if (perms - ZooDefs.Perms.DELETE >= 0) { 
                sb.append("d");
                perms = perms - ZooDefs.Perms.DELETE;
            }
    
            if (perms - ZooDefs.Perms.CREATE >= 0) { 
                sb.append("c");
                perms = perms - ZooDefs.Perms.CREATE;
            }
    
            if (perms - ZooDefs.Perms.WRITE >= 0) { 
                sb.append("w");
                perms = perms - ZooDefs.Perms.WRITE;
            }
    
            if (perms - ZooDefs.Perms.READ >= 0) { 
                sb.append("r");
                perms = perms - ZooDefs.Perms.READ;
            }
    
            return sb.toString();
        }
    
        // 批量执行: 批量创建节点, 要么全部成功, 要么全部失败
        @Test
        public void multi() throws KeeperException, InterruptedException { 
    
            //批量操作
            List<Op> opList = new ArrayList<>();
            opList.add(Op.create("/nodes", "nodes".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
            opList.add(Op.create("/nodes/A", "aa".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
            opList.add(Op.create("/nodes/B", "bb".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
            opList.add(Op.create("/nodes/C", "cc".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
    // 如果添加此行, 则全部失败
    // opList.add(Op.create("/nodes/D/dd", "dd".getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT));
    
    
            List<OpResult> multi = zooKeeper.multi(opList);
            for (OpResult opResult : multi) { 
    
            }
            multi.stream()
                    .map(opResult -> (OpResult.CreateResult) opResult)
                    .forEach(result -> System.out.println(result.getPath() + "-> " + result.getType()));
    
        }
    
    }