【1】地址占用

异常如下所示：

org.apache.zookeeper.server.admin.AdminServer$AdminServerException: Problem starting AdminServer on address 0.0.0.0, port 8080 and command URL /commands
        at org.apache.zookeeper.server.admin.JettyAdminServer.start(JettyAdminServer.java:107)
        at org.apache.zookeeper.server.ZooKeeperServerMain.runFromConfig(ZooKeeperServerMain.java:138)
        at org.apache.zookeeper.server.ZooKeeperServerMain.initializeAndRun(ZooKeeperServerMain.java:106)
        at org.apache.zookeeper.server.ZooKeeperServerMain.main(ZooKeeperServerMain.java:64)
        at org.apache.zookeeper.server.quorum.QuorumPeerMain.initializeAndRun(QuorumPeerMain.java:128)
        at org.apache.zookeeper.server.quorum.QuorumPeerMain.main(QuorumPeerMain.java:82)
Caused by: java.io.IOException: Failed to bind to /0.0.0.0:8080
        at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:346)
        at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:308)
        at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
        at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:236)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
        at org.eclipse.jetty.server.Server.doStart(Server.java:396)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
        at org.apache.zookeeper.server.admin.JettyAdminServer.start(JettyAdminServer.java:103)
        ... 5 more
Caused by: java.net.BindException: 地址已在使用
        at sun.nio.ch.Net.bind0(Native Method)
        at sun.nio.ch.Net.bind(Net.java:433)
        at sun.nio.ch.Net.bind(Net.java:425)
        at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
        at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
        at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:342)
        ... 12 more

AdminServer端口默认使用8080，上面异常表示8080端口已经被使用。两种解决办法：解决端口占用或者更换管理端口。

更换端口如下所示：

admin.serverPort=18080

或者可以选择停掉这个服务，在启动脚本中增加-Dzookeeper.admin.enableServer=false

【2】找不到或无法加载主类 org.apache.zookeeper.server.quorum.QuorumPeerMain

如果你使用的是3.5.5版本，那么请下载使用apache-zookeeper-3.5.5-bin.tar.gz而非apache-zookeeper-3.5.5.tar.gz，后者是源码包，即src包。

下载地址如下：https://mirrors.tuna.tsinghua.edu.cn/apache/zookeeper/zookeeper-3.5.5/