08. Zookeeper JavaAPI-环境搭建

太过爱你忘了你带给我的痛 2022-03-18 02:26 206阅读 0赞

> Zookeeper 提供了Java 访问的API, 但是笔者API 并不是太友好, 使用起来并不方便. 笔者认为, 倘若在生产环境下需要直接操作Zookeeper, 那么笔者建议对常用API 做二次封装.

## 1. Java 开发环境搭建 ##

新建一maven 项目, 引入依赖

### 1.1 pom 依赖 ###

引入zookeeper 核心依赖, 顺便引入单元测试和日志依赖.

<dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.6</version>
        </dependency>
    </dependencies>

### 1.2 日志输出 ###

Zookeeper 默认采用log4j 输出日志, 因此在类加载路径下添加log4j.properties 配置文件

log4j.rootLogger=INFO, stdout  
    log4j.appender.stdout=org.apache.log4j.ConsoleAppender  
    log4j.appender.stdout.layout=org.apache.log4j.PatternLayout  
    log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n  
    log4j.appender.logfile=org.apache.log4j.FileAppender  
    log4j.appender.logfile.File=target/spring.log  
    log4j.appender.logfile.layout=org.apache.log4j.PatternLayout  
    log4j.appender.logfile.layout.ConversionPattern=%d %p [%c] - %m%n

## 2. 创建Zookeeper 连接 ##

Java 对Zookeeper 的操作全部封装在Zookeeper 对象中, 需要先创建Zookeeper对象, 与Zookeeper服务建立连接. 获取到Zookeeper 连接对象之后, 就可以对zNode 进行操作了.

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;
        
        @Test
        public 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 ***********************");
        }
    }