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。
org.apache.zookeeper.KeeperException$ConnectionLossException: KeeperErrorCode = ConnectionLoss for /eclipse20171118
at org.apache.zookeeper.KeeperException.create(KeeperException.java:)
at org.apache.zookeeper.KeeperException.create(KeeperException.java:)
at org.apache.zookeeper.ZooKeeper.create(ZooKeeper.java:)
at com.bie.lesson01.ZookeeperClient.zookeeperCreate(ZookeeperClient.java:)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$.runReflectiveCall(FrameworkMethod.java:)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:)
at org.junit.runners.ParentRunner$.run(ParentRunner.java:)
at org.junit.runners.ParentRunner$.schedule(ParentRunner.java:)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:)
at org.junit.runners.ParentRunner.access$(ParentRunner.java:)
at org.junit.runners.ParentRunner$.evaluate(ParentRunner.java:)
at org.junit.runners.ParentRunner.run(ParentRunner.java:)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:)
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。
） 临时生效，重启后复原
开启： service iptables start
关闭： service iptables stop
） 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