.personSunflowerP { background: rgba(51, 153, 0, 0.66); border-bottom: 1px solid rgba(0, 102, 0, 1); border-top-left-radius: 7px; border-top-right-radius: 7px; color: rgba(255, 255, 255, 1); height: 1.8em; line-height: 1.8em; padding: 5px }

以下为一个完整JAVA操作Zookeeper项目步骤：

1. 项目中pom.xml中添加需要的依赖jar包信息

<dependencies>

    <dependency>

        <groupId>org.apache.zookeeper</groupId>

        <artifactId>zookeeper</artifactId>

        <version>3.4.9</version>

    </dependency>

    <dependency>

        <groupId>com.101tec</groupId>

        <artifactId>zkclient</artifactId>

        <version>0.10</version>

    </dependency>

</dependencies>

2. 在resource下添加log4j.properties日志打印信息

log4j.rootLogger=DEBUG,myConsole

log4j.appender.myConsole=org.apache.log4j.ConsoleAppender

log4j.appender.myConsole.ImmediateFlush=true

log4j.appender.myConsole.Target=System.out

log4j.appender.myConsole.layout=org.apache.log4j.PatternLayout

log4j.appender.myConsole.layout.ConversionPattern=[%-5p] %d(%r) --> [%t] %l: %m %x %n

3. 使用Java代码操作Zookeeper

　　包括创建节点、设置节点值、获取节点值、判断节点是否存在

　　创建节点时，存在四种模式：（即在createZKNode方法中）

　　　　1. CreateMode.PERSISTENT ：持久节点，一旦创建就保存到硬盘上面

　　　　2. CreateMode.SEQUENTIAL ： 顺序持久节点

　　　　3. CreateMode.EPHEMERAL ：临时节点，创建以后如果断开连接则该节点自动删除

　　　　4. CreateMode.EPHEMERAL_SEQUENTIAL ：顺序临时节点

　　创建ZKOperaDemo.java类：

package com.hxc.zookeeperDemo;

import java.io.IOException;

import java.util.ArrayList;

import org.apache.zookeeper.CreateMode;

import org.apache.zookeeper.KeeperException;

import org.apache.zookeeper.WatchedEvent;

import org.apache.zookeeper.Watcher;

import org.apache.zookeeper.ZooKeeper;

import org.apache.zookeeper.data.ACL;

import org.apache.zookeeper.data.Stat;

import org.apache.zookeeper.ZooDefs.Ids;

/**

 *

 * @author sun_flower

 *

 */

public class ZKOperaDemo {

    private static String connectString = "192.168.202.132:2181";

    private static int sessionTimeout = 50 * 1000;

    /**

     * 连接Zookeeper服务器

     * @return

     * @throws IOException

     */

    public ZooKeeper connectionZooKeeper() throws IOException {

        ZooKeeper zooKeeper = new ZooKeeper(connectString, sessionTimeout, new Watcher() {

            public void process(WatchedEvent event) {

                //可做其他操作（设置监听或观察者）

            }

        });

        return zooKeeper;

    }

    /**

     * 创建节点

     * 1. CreateMode.PERSISTENT ：持久节点，一旦创建就保存到硬盘上面

　　　  2.  CreateMode.SEQUENTIAL ： 顺序持久节点

　　　  3.  CreateMode.EPHEMERAL ：临时节点，创建以后如果断开连接则该节点自动删除

　　　  4.  CreateMode.EPHEMERAL_SEQUENTIAL ：顺序临时节点

     * @param zooKeeper Zookeeper已经建立连接的对象

     * @param path 要创建节点的路径

     * @param data 该节点上的数据

     * @return 返回创建的节点的路径

     * @throws KeeperException

     * @throws InterruptedException

     */

    public String createZKNode(ZooKeeper zooKeeper, String path, String data) throws KeeperException, InterruptedException {

        byte[] bytesData = data.getBytes();

        //访问控制列表

        ArrayList<ACL> openAclUnsafe = Ids.OPEN_ACL_UNSAFE;

        //创建模式

        CreateMode mode = CreateMode.PERSISTENT;

        String result = zooKeeper.create(path, bytesData, openAclUnsafe, mode);

        System.out.println("创建节点成功: " + result);

        return result;

    }

    /**

     * 获取节点上的数据

     * @param zooKeeper Zookeeper已经建立连接的对象

     * @param path 节点路径

     * @return 返回节点上的数据

     * @throws KeeperException

     * @throws InterruptedException

     */

    public String getZKNodeData(ZooKeeper zooKeeper, String path) throws KeeperException, InterruptedException {

        byte[] data = zooKeeper.getData(path, false, new Stat());

//        System.out.println("该节点" + path + "上的数据伟: " + new String(data));

        return new String(data);

    }

    /**

     * 设置节点上的数据

     * @param zooKeeper Zookeeper已经建立连接的对象

     * @param path 节点路径

     * @param data

     * @return

     * @throws KeeperException

     * @throws InterruptedException

     */

    public Stat setZKNodeData(ZooKeeper zooKeeper, String path, String data) throws KeeperException, InterruptedException {

        return zooKeeper.setData(path, data.getBytes(), -1);

    }

    /**

     * 判断节点是否存在

     * @param zooKeeper

     * @param path 节点路径

     * @return

     * @throws KeeperException

     * @throws InterruptedException

     */

    public Stat isExitZKPath(ZooKeeper zooKeeper, String path) throws KeeperException, InterruptedException {

        Stat stat = zooKeeper.exists(path, false);

        return stat;

    }

}

4. 测试代码TestZK.java

　　1）测试连接是否成功：

　　//1.测试连接是否成功

    @Test

    public void testConnection() throws IOException, InterruptedException {

        ZKOperaDemo zkOperaDemo = new ZKOperaDemo();

        ZooKeeper zooKeeper = zkOperaDemo.connectionZooKeeper();

        System.out.println("====================");

        System.out.println(zooKeeper);

        System.out.println("====================");

        Thread.sleep(Long.MAX_VALUE);

    }

运行之后控制台打印的信息如下，最后两条可以看到一直在打印 ping ZooKeeper服务的信息（Got ping response for sessionid: 0x16c9968e7d0000e after 2ms  ）

[INFO ] 2019-08-21 09:42:56,068(0) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:zookeeper.version=3.4.9-1757313, built on 08/23/2016 06:50 GMT

[INFO ] 2019-08-21 09:42:56,079(11) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:host.name=LAPTOP-L6EGT293

[INFO ] 2019-08-21 09:42:56,079(11) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:java.version=1.8.0_60

[INFO ] 2019-08-21 09:42:56,080(12) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:java.vendor=Oracle Corporation

[INFO ] 2019-08-21 09:42:56,080(12) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:java.home=D:\ProgramFiles\JRE1.8

[INFO ] 2019-08-21 09:42:56,081(13) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:java.class.path=D:\eclipse_mySpaces\zookeeperDemo\target\test-classes;D:\eclipse_mySpaces\zookeeperDemo\target\classes;D:\ProgramFiles\eclipse\plugins\org.junit_4.12.0.v201504281640\junit.jar;D:\ProgramFiles\eclipse\plugins\org.hamcrest.core_1.3.0.v20180420-1519.jar;C:\Users\sun_flower\.m2\repository\org\apache\zookeeper\zookeeper\3.4.9\zookeeper-3.4.9.jar;C:\Users\sun_flower\.m2\repository\org\slf4j\slf4j-api\1.6.1\slf4j-api-1.6.1.jar;C:\Users\sun_flower\.m2\repository\org\slf4j\slf4j-log4j12\1.6.1\slf4j-log4j12-1.6.1.jar;C:\Users\sun_flower\.m2\repository\log4j\log4j\1.2.16\log4j-1.2.16.jar;C:\Users\sun_flower\.m2\repository\jline\jline\0.9.94\jline-0.9.94.jar;C:\Users\sun_flower\.m2\repository\io\netty\netty\3.10.5.Final\netty-3.10.5.Final.jar;C:\Users\sun_flower\.m2\repository\com\101tec\zkclient\0.10\zkclient-0.10.jar;D:\ProgramFiles\eclipse\configuration\org.eclipse.osgi\407\0\.cp;D:\ProgramFiles\eclipse\configuration\org.eclipse.osgi\406\0\.cp

[INFO ] 2019-08-21 09:42:56,082(14) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:java.library.path=D:\ProgramFiles\JRE1.8\bin;C:\WINDOWS\Sun\Java\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\NVIDIA Corporation\NVIDIA NvDLISR;D:\ProgramFiles\JDK1.8\bin;D:\ProgramFiles\JDK1.8\jre\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;D:\ProgramFiles\apache-maven-3.3.9\bin;D:\ProgramFiles\mysql5.0\bin;C:\Users\sun_flower\AppData\Local\Microsoft\WindowsApps;;D:\ProgramFiles\IntelliJIDEA2018.3.5\bin;;.

[INFO ] 2019-08-21 09:42:56,082(14) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:java.io.tmpdir=C:\Users\SUN_FL~1\AppData\Local\Temp\

[INFO ] 2019-08-21 09:42:56,083(15) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:java.compiler=<NA>

[INFO ] 2019-08-21 09:42:56,083(15) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:os.name=Windows 10

[INFO ] 2019-08-21 09:42:56,083(15) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:os.arch=amd64

[INFO ] 2019-08-21 09:42:56,084(16) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:os.version=10.0

[INFO ] 2019-08-21 09:42:56,084(16) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:user.name=sun_flower

[INFO ] 2019-08-21 09:42:56,084(16) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:user.home=C:\Users\sun_flower

[INFO ] 2019-08-21 09:42:56,084(16) --> [main] org.apache.zookeeper.Environment.logEnv(Environment.java:100): Client environment:user.dir=D:\eclipse_mySpaces\zookeeperDemo

[INFO ] 2019-08-21 09:42:56,087(19) --> [main] org.apache.zookeeper.ZooKeeper.<init>(ZooKeeper.java:438): Initiating client connection, connectString=192.168.202.132:2181 sessionTimeout=50000 watcher=com.hxc.zookeeperDemo.ZKOperaDemo$1@6073f712

[DEBUG] 2019-08-21 09:42:56,094(26) --> [main] org.apache.zookeeper.ClientCnxn.<clinit>(ClientCnxn.java:117): zookeeper.disableAutoWatchReset is false

[INFO ] 2019-08-21 09:42:56,296(228) --> [main] org.apache.zookeeper.ZooKeeper.<init>(ZooKeeper.java:438): Initiating client connection, connectString=192.168.202.132:2181 sessionTimeout=50000 watcher=com.hxc.zookeeperDemo.ZKOperaDemo$1@6ea6d14e

====================

State:CONNECTING sessionid:0x0 local:null remoteserver:null lastZxid:0 xid:1 sent:0 recv:0 queuedpkts:0 pendingresp:0 queuedevents:0

====================

[INFO ] 2019-08-21 09:42:56,317(249) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.logStartConnect(ClientCnxn.java:1032): Opening socket connection to server 192.168.202.132/192.168.202.132:2181. Will not attempt to authenticate using SASL (unknown error)

[INFO ] 2019-08-21 09:42:56,317(249) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.logStartConnect(ClientCnxn.java:1032): Opening socket connection to server 192.168.202.132/192.168.202.132:2181. Will not attempt to authenticate using SASL (unknown error)

[INFO ] 2019-08-21 09:42:56,325(257) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.primeConnection(ClientCnxn.java:876): Socket connection established to 192.168.202.132/192.168.202.132:2181, initiating session

[DEBUG] 2019-08-21 09:42:56,327(259) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.primeConnection(ClientCnxn.java:949): Session establishment request sent on 192.168.202.132/192.168.202.132:2181

[INFO ] 2019-08-21 09:42:56,333(265) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.onConnected(ClientCnxn.java:1299): Session establishment complete on server 192.168.202.132/192.168.202.132:2181, sessionid = 0x16c9968e7d0000d, negotiated timeout = 40000

[INFO ] 2019-08-21 09:42:57,320(1252) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.primeConnection(ClientCnxn.java:876): Socket connection established to 192.168.202.132/192.168.202.132:2181, initiating session

[DEBUG] 2019-08-21 09:42:57,321(1253) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.primeConnection(ClientCnxn.java:949): Session establishment request sent on 192.168.202.132/192.168.202.132:2181

[INFO ] 2019-08-21 09:42:57,325(1257) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.onConnected(ClientCnxn.java:1299): Session establishment complete on server 192.168.202.132/192.168.202.132:2181, sessionid = 0x16c9968e7d0000e, negotiated timeout = 40000

[DEBUG] 2019-08-21 09:43:09,671(13603) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:742): Got ping response for sessionid: 0x16c9968e7d0000d after 6ms

[DEBUG] 2019-08-21 09:43:10,656(14588) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:742): Got ping response for sessionid: 0x16c9968e7d0000e after 2ms

如果控制台报如下错误（java.net.ConnectException: Connection refused: no further information），则可能是ZooKeeper服务没有开启或者防火墙没有关闭或防火墙没有开启2181端口

[WARN ] 2019-08-21 09:59:42,274(2080) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1162): Session 0x0 for server null, unexpected error, closing socket connection and attempting reconnect

java.net.ConnectException: Connection refused: no further information

    at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)

    at sun.nio.ch.SocketChannelImpl.finishConnect(Unknown Source)

    at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:361)

    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1141)

[DEBUG] 2019-08-21 09:59:42,276(2082) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxnSocketNIO.cleanup(ClientCnxnSocketNIO.java:203): Ignoring exception during shutdown input

　　2）测试连接ZooKeeper服务通后之后，就可以完整的测试其他功能了

　　所有完整的测试代码：（测试创建节点、设置节点值、获取节点值、判断节点是否存在）

package com.hxc.zookeeperDemo;

import java.io.IOException;

import org.apache.zookeeper.KeeperException;

import org.apache.zookeeper.ZooKeeper;

import org.apache.zookeeper.data.Stat;

import org.junit.Test;

public class TestZK {

    //1.测试连接是否成功

    @Test

    public void testConnection() throws IOException, InterruptedException {

        ZKOperaDemo zkOperaDemo = new ZKOperaDemo();

        ZooKeeper zooKeeper = zkOperaDemo.connectionZooKeeper();

        System.out.println("====================");

        System.out.println(zooKeeper);

        System.out.println("====================");

        Thread.sleep(Long.MAX_VALUE);

    }

    private ZKOperaDemo nodeOperation = new ZKOperaDemo();

    private ZooKeeper zooKeeper = null;

    {

        try {

            zooKeeper = nodeOperation.connectionZooKeeper();

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

    //测试创建节点

    @Test

    public void testCreateZKNode() throws KeeperException, InterruptedException {

        String result = nodeOperation.createZKNode(zooKeeper, "/address", "ShenZhen");

        System.out.println(result);

    }

    //测试获取节点数据

    @Test

    public void testGetZKNodeData() throws KeeperException, InterruptedException {

        String result = nodeOperation.getZKNodeData(zooKeeper, "/address");

        System.out.println(result);

    }

    //测试设置节点数据

    @Test

    public void testSetZKNodeData() throws KeeperException, InterruptedException {

        Stat stat = nodeOperation.setZKNodeData(zooKeeper, "/address", "Shen Zhen update");

        System.out.println(stat);    //结果是二进制数据

        if(null != null)

        System.out.println(stat.getCversion());

    }

    //测试节点是否存在

    @Test

    public void testIsExitZKPath() throws KeeperException, InterruptedException {

        Stat stat = nodeOperation.isExitZKPath(zooKeeper, "/addressaa");

        System.out.println(stat);    //结果是二进制数据  如果节点不存在，则返回null

        if(null != null)

            System.out.println(stat.getCversion());

    }

}

　　3）在Zookeeper服务上就能看到测试后的信息了：

5. zookeeper的通知机制

　　在初次建立连接和设置节点时均可设置观察者（监听），每一次的观察只使用一次，每次使用完观察若还想监听下次的操作，需要重新设置观察者。即Watcher设置到节点上之后是一次性的，通知一次之后就会失效。所以我们在通知的回调方法中接收执行通知操作后需要再继续设置一个Watcher。

　　实现持续的观察代码部分：（递归回调）

　　//通知机制

    /**

     *   监听节点 获取节点上的数据

     * @param zooKeeper Zookeeper已经建立连接的对象

     * @param path 节点路径

     * @return 返回节点上的数据

     * @throws KeeperException

     * @throws InterruptedException

     */

    public void getZKNodeData2(final ZooKeeper zooKeeper, final String path) throws KeeperException, InterruptedException {

        byte[] data = zooKeeper.getData(path, new Watcher() {

            public void process(WatchedEvent event) {

                try {

                    String data2 = ZKOperaDemo.process(zooKeeper, path);

                    System.out.println("第一次调用============= " + data2 + " =================");

                } catch (KeeperException e) {

                    e.printStackTrace();

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

            }

        }, new Stat());

        System.out.println("该节点" + path + "上的数据为: " + new String(data));

        Thread.sleep(Long.MAX_VALUE);

    }

    public static String process(final ZooKeeper zooKeeper, final String path) throws KeeperException, InterruptedException {

        byte[] data = zooKeeper.getData(path, new Watcher() {

            public void process(WatchedEvent event) {

                try {

                    String data = ZKOperaDemo.process(zooKeeper, path);

                    System.out.println("============= " + data + " =================");

                } catch (KeeperException e) {

                    e.printStackTrace();

                } catch (InterruptedException e) {

                    e.printStackTrace();

                }

            }

        }, new Stat());

        return new String(data);

    }

测试代码：

　　 @Test

    public void testGetZKNodeData2() throws KeeperException, InterruptedException {

        nodeOperation.getZKNodeData2(zooKeeper, "/address");

    }

启动了这个服务后，然后向节点设置值之后，就可以在控制台打印相应的监听信息：

　　1）初次启动时，控制台打印的部分主要信息：

[DEBUG] 2019-08-21 16:08:16,230(95) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:843): Reading reply sessionid:0x16cb1e90922000e, packet:: clientPath:null serverPath:null finished:false header:: 1,4  replyHeader:: 1,512,0  request:: '/address,T  response:: #5368656e205a68656e20757064617465,s{448,511,1566270677948,1566374882666,19,0,0,0,16,0,448}

该节点/address上的数据为: Shen Zhen update

[DEBUG] 2019-08-21 16:08:29,564(13429) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:742): Got ping response for sessionid: 0x16cb1e90922000e after 2ms

　　2）在服务端或者在测试获取节点值的部分重新设置：（为了更直观查看，在服务端设置值）

　　然后控制台上马上打印对应的观察者信息：

[DEBUG] 2019-08-21 16:10:27,104(130969) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:843): Reading reply sessionid:0x16cb1e90922000e, packet:: clientPath:null serverPath:null finished:false header:: 2,4  replyHeader:: 2,515,0  request:: '/address,T  response:: #6265696a696e67,s{448,515,1566270677948,1566375027091,20,0,0,0,7,0,448}

第一次调用============= beijing =================

[DEBUG] 2019-08-21 16:10:40,437(144302) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:742): Got ping response for sessionid: 0x16cb1e90922000e after 1ms

　　 3）再次调用：

　　控制台打印的信息：（会持续的监听）

[DEBUG] 2019-08-21 16:12:36,498(260363) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:843): Reading reply sessionid:0x16cb1e90922000e, packet:: clientPath:null serverPath:null finished:false header:: 3,4  replyHeader:: 3,516,0  request:: '/address,T  response:: #7368616e67686169,s{448,516,1566270677948,1566375156485,21,0,0,0,8,0,448}

============= shanghai =================

[DEBUG] 2019-08-21 16:12:49,832(273697) --> [main-SendThread(192.168.202.132:2181)] org.apache.zookeeper.ClientCnxn$SendThread.readResponse(ClientCnxn.java:742): Got ping response for sessionid: 0x16cb1e90922000e after 1ms

以上就是简单的java操作zookeeper的方式

 希望各位给出宝贵意见，不甚感激！！

Java代码操作zookeeper的更多相关文章

  1. zookeeper java api（使用java代码操作zookeeper）

    1 导入相关的pom依赖 <dependency> <groupId>org.apache.zookeeper</groupId> <artifactId&g ...

  2. Java curator操作zookeeper获取kafka

    Java curator操作zookeeper获取kafka Curator是Netflix公司开源的一个Zookeeper客户端,与Zookeeper提供的原生客户端相比,Curator的抽象层次更 ...

  3. Java代码操作HDFS测试类

    1.Java代码操作HDFS需要用到Jar包和Java类 Jar包: hadoop-common-2.6.0.jar和hadoop-hdfs-2.6.0.jar Java类: java.net.URL ...

  4. zookeeper - 通过java代码连接zookeeper(2)

    首先创建一个Maven项目 <?xml version="1.0" encoding="UTF-8"?> <project xmlns=&qu ...

  5. 使用java代码操作Redis

    1导入pom.xml依赖 <dependency> <groupId>redis.clients</groupId> <artifactId>jedis ...

  6. java代码操作Redis

    1.导入需要的pom依赖 <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEn ...

  7. 分享知识-快乐自己：java代码 操作 solr

    POM 文件: <!-- solr客户端 --> <dependency> <groupId>org.apache.solr</groupId> < ...

  8. 大数据之路week07--day01（HDFS学习，Java代码操作HDFS，将HDFS文件内容存入到Mysql）

    一.HDFS概述 数据量越来越多,在一个操作系统管辖的范围存不下了,那么就分配到更多的操作系统管理的磁盘中,但是不方便管理和维护,因此迫切需要一种系统来管理多台机器上的文件,这就是分布式文件管理系统 ...

  9. java：nginx（java代码操作ftp服务器）

    1.检查是否安装了vsftpd [root@linux01 ~]# rpm -qa|grep vsftpd 2.安装vsftpd [root@linux01 ~]# yum -y install vs ...

随机推荐

  1. python3 依赖倒置原则示例

    场景 针对园区停车信息,需要对各个公司提供的停车数据进行整合并录入自家公司的大数据平台 数据的录入无外乎就是对数据的增删改查 下面上一个常规的写法(未符合依赖倒置),整合来自 长安和丰田 的停车数据 ...

  2. 大数据 | 分布式文件系统 HDFS

    HDFS全称Hadoop Distributed File System,看名字就知道是Hadoop生态的一个组件,它是一个分布式文件系统. 它的出现解决了独立机器存储大数据集的压力,它将数据集进行切 ...

  3. CentOS-Docker安装MongoDB(单点)

    下载镜像 $ docker pull mongo 创建相关目录 $ mkdir -p /usr/mongo/data /usr/mongo/dump 运行镜像 $ docker run --resta ...

  4. 26 bash shell中的信号

    当没有任何捕获时,一个交互式 Bash Shell 会忽略 SIGTERM(发送到进程的 TERM 信号用于要求进程终止) 和 SIGQUIT(当用户要求进程执行 core dump 时,QUIT 信 ...

  5. NTP配置（广播模式并且无认证）

    1.服务器端 1.1服务器本地同步自己的时钟,否则无法对外提供NTP服务 [NTP]ntp refclock-master 3 [NTP]ntp refclock-master 127.127.1.1 ...

  6. Python装饰器、迭代器&生成器、re正则表达式、字符串格式化

    Python装饰器.迭代器&生成器.re正则表达式.字符串格式化 本章内容: 装饰器 迭代器 & 生成器 re 正则表达式 字符串格式化 装饰器 装饰器是一个很著名的设计模式,经常被用 ...

  7. 创建自己的RSA密钥来保护web.config 加密数据库连接字符串

    通过创建自己的RSA密钥来保护web.config1创建RSA密钥:C:\Windows\Microsoft.NET\Framework64\v4.0.30319>aspnet_regiis - ...

  8. 高校表白App-团队冲刺第三天

    今天要做什么 今天开站立会议的时候,忽然发觉在一个完整的App上好像是有一些引导页的,比如说在第一次使用App的时候,或者是在使用App的时候会出现新手指引操作. 做了什么 通过查阅资料来学习View ...

  9. Java基础00-学生管理系统16

    1. 学生管理系统 1.1 项目演示 1.2 实现思路 1.3 定义学生类 public class Student { private String sid; private String name ...

  10. [刘阳Java]_Spring AOP入门_第7讲

    AOP技术个人认为是能够完善(改善)面向对象编程OOP.为什么这么说,我们得先从AOP的概念说起,然后通过一段简单的例子加以佐证.这样子大家就可以慢慢地了解AOP 1. AOP概念 AOP为Aspec ...