1：如果有一天，你有幸看到了这个错误，也许你像我一样low，因为此时，你已经准备开发Zookeeper程序了，却还没有把Zookeeper的服务启动起来。

 1 org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /eclipse20171118
 2     at org.apache.zookeeper.KeeperException.create(KeeperException.java:99)
 3     at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
 4     at org.apache.zookeeper.ZooKeeper.create(ZooKeeper.java:783)
 5     at com.bie.lesson01.ZookeeperClient.zookeeperCreate(ZookeeperClient.java:51)
 6     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 7     at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 8     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 9     at java.lang.reflect.Method.invoke(Unknown Source)
10     at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
11     at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
12     at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
13     at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
14     at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
15     at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
16     at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
17     at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
18     at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
19     at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
20     at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
21     at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
22     at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
23     at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
24     at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
25     at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
26     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
27     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
28     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
29     at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

解决办法，启动你的Zookeeper。记得启动起来以后进行查看。

如果你的Zookeeper启动起来了，还报这个错误，那么就是关闭防火墙即可。

 CentOS Linux开启和关闭防火墙命令有两种，一种是临时的，重启即复原；另外一种是永久性的，重启不会复原。  
    1） 临时生效，重启后复原  
    开启： service iptables start  
    关闭： service iptables stop  
    2） 永久性生效，重启后不会复原  
    开启： chkconfig iptables on  
    关闭： chkconfig iptables off

停更.......

2017-11-18 17:12:35