鲁春利的工作笔记,谁说程序员不能有文艺范?



    为了避免存储在ZooKeeper服务器上的数据被其他进程干扰或人为操作修改,需要对ZooKeeper上的数据访问进行权限控制(Access Control)。ZooKeeper提供了ACL的权限控制机制,来控制客户端对数据节点的访问控制。

    ZooKeeper提供了多种权限控制模式(Scheme),分别是world、auth、digest、ip和super。
开发人员如果要使用ZooKeeper的权限控制功能,需要在ZooKeeper回话创建后,给该回话添加相关的权限信息(AuthInfo)。ZooKeeper客户端提供了相应的API接口来进行权限信息的设置:

    addAuthInfo(String scheme, byte [] auth)
    scheme :权限控制模式,world、auth、digest、ip和super
    auth :具体的权限信息

    说明:该接口主要用于为当前ZooKeeper会话添加权限信息,之后凡是通过该会话对ZooKeeper服务端进行的任何操作,都会带上该权限信息。

    使用包含权限信息的ZooKeeper会话操作数据节点

package com.invic.zk;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;

/**
 * 
 * @author lucl
 *
 */
public class CusZookeeperACL {

    /**
     * @param args
     */
    public static void main(String[] args) {
        String path = "/zk-book-auth";
        String childPath = path + "/child";
        
        String connectString = "nnode:2181,dnode1:2181,dnode2:2181";
        int sessionTimeout = 30 * 1000;
        
        System.out.println("===============第一次、创建节点================");
        {
            try {
               final CountDownLatch latch = new CountDownLatch(1);
                ZooKeeper zk = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
    
                    @Override
                    public void process(WatchedEvent event) {
                        System.out.println(event.getState());        // SyncConnected
                        if (KeeperState.SyncConnected == event.getState()) {
                            System.out.println("zk session established : SyncConnected.");
                            if (EventType.None == event.getType() && null == event.getPath()) {
                                latch.countDown();
                            } 
                        }
                    }
                });
                
                latch.await();
                
                // 权限信息
                //        模式:world、auth、digest、ip和super
                //        auth:具体权限信息
                zk.addAuthInfo("digest", "foo:true".getBytes());
                
                // 创建节点,此时节点就受到了权限控制
                byte [] initData = "init".getBytes();
                byte [] childData = "child".getBytes();
                zk.create(path, initData , Ids.CREATOR_ALL_ACL, CreateMode.PERSISTENT);
                zk.create(childPath, childData, Ids.CREATOR_ALL_ACL, CreateMode.EPHEMERAL);
                
                Thread.sleep(sessionTimeout);
            } catch (IOException e) {
                e.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (KeeperException e) {
                e.printStackTrace();
            }
        }
        
        System.out.println("==============第二次、未带权限信息的连接===============");
        {
            ZooKeeper zk2 = null;
            try {
                zk2 = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
    
                    @Override
                    public void process(WatchedEvent event) {
                        System.out.println(event.getState());        // SyncConnected
                    }
                });
            } catch (IOException e) {
                e.printStackTrace();
            } 

            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            
            if (null != zk2) {
                Stat stat = new Stat();
                try {
                    // 获取数据报错: KeeperErrorCode = NoAuth for /zk-book-auth
                    byte [] bytes = zk2.getData(path, false, stat);        
                    System.out.println("Get data from zk : " + new String(bytes));
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("==============第三次、正确的权限信息的连接===============");
        {
            ZooKeeper zk3 = null;
            try {
                zk3 = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
    
                    @Override
                    public void process(WatchedEvent event) {
                        System.out.println(event.getState());        // SyncConnected
                    }
                });
                
                zk3.addAuthInfo("digest", "foo:true".getBytes());
            } catch (IOException e) {
                e.printStackTrace();
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            
            if (null != zk3) {
                try {
                    byte[] datas = zk3.getData(path, true, null);
                    // Get data from zk : init
                    System.out.println("Get data from zk : " + new String(datas));    
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }    
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("==============第四次、错误的权限信息的连接===============");
        {
            ZooKeeper zk4 = null;
            try {
                zk4 = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
    
                    @Override
                    public void process(WatchedEvent event) {
                        System.out.println(event.getState());        // SyncConnected
                    }
                });
                
                zk4.addAuthInfo("digest", "foo:false".getBytes());
            } catch (IOException e) {
                e.printStackTrace();
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            
            if (null != zk4) {
                try {
                    byte[] datas = zk4.getData(path, true, null);
                    // Get data from zk : init
                    System.out.println("Get data from zk : " + new String(datas));    
                } catch (KeeperException e) {
                    e.printStackTrace();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }    
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("==============第五次、未指定权限信息的连接===============");
        {
            ZooKeeper zk5 = null;
            try {
                zk5 = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
    
                    @Override
                    public void process(WatchedEvent event) {
                        System.out.println(event.getState());        // SyncConnected
                    }
                });
            } catch (IOException e) {
                e.printStackTrace();
            } 
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            
            if (null != zk5) {
                try {
                    // 删除path的子节点KeeperErrorCode = NoAuth for /zk-book-auth/child
                    zk5.delete(path + "/child", -1);            
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (KeeperException e) {
                    e.printStackTrace();
                }
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("==============第六次、指定权限信息的连接===============");
        {
            ZooKeeper zk6 = null;
            try {
                zk6 = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
    
                    @Override
                    public void process(WatchedEvent event) {
                        System.out.println(event.getState());        // SyncConnected
                    }
                });
                
                zk6.addAuthInfo("digest", "foo:true".getBytes());
            } catch (IOException e) {
                e.printStackTrace();
            } 
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            
            if (null != zk6) {
                try {
                    // 成功删除
                    zk6.delete(childPath, -1);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (KeeperException e) {
                    e.printStackTrace();
                }
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

        System.out.println("==============第七次、未指定权限信息的连接===============");
        {
            ZooKeeper zk7 = null;
            try {
                zk7 = new ZooKeeper(connectString, sessionTimeout, new Watcher() {
    
                    @Override
                    public void process(WatchedEvent event) {
                        System.out.println(event.getState());        // SyncConnected
                    }
                });
            } catch (IOException e) {
                e.printStackTrace();
            } 
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            
            if (null != zk7) {
                try {
                    // 本次为删除path路径,成功删除--权限信息只对子节点起左右
                    zk7.delete(path, -1);            
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (KeeperException e) {
                    e.printStackTrace();
                }
            }
            
            try {
                Thread.sleep(sessionTimeout);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    
}