一、找不到或无法加载主类 org.apache.zookeeper.server.quorum.QuorumPeerMain-新版本zookeeper易犯错误
解决方法：去zk的官网下载，别去github上下载release版本
原因：
1）总结：3.5.5之前也去官网下载tar包，3.5.5之后带有bin名称的包才是我们想要的下载可以直接使用的里面有编译后的二进制的包，而之前的普通的tar.gz的包里面是只是源码的包无法直接使用。
2）下载后的readme文档写了区别了 apache-zookeeper-[version].tar.gz - Contains all the source files which can be built by running: mvn clean install - To generate an aggregated apidocs for zookeeper-server and zookeeper-jute: mvn javadoc:aggregate (generated files will be at target/site/apidocs) apache-zookeeper-[version]-bin.tar.gz - Contains all the jar files required to run ZooKeeper documentation can also be found in the docs folder