序：本以为今天花点时间将WordCount例子完全理解到，但高估自己了，更别说我只是在大学选修一学期的java，之后再也没碰过java语言了
总的来说，从宏观上能理解具体的程序思路，但具体到每个代码有什么作用，什么原理，那还需要花点时间，毕竟需要一点java基础和hadoop的运行机制的知识
首先启动hadoop；
[hadoop@hadoop01 eclipse]$ cd ~/hadoop-3.2.0 [hadoop@hadoop01 hadoop-3.2.0]$ sbin/start-all.sh WARNING: Attempting to start all Apache Hadoop daemons as hadoop in 10 seconds. WARNING: This is not a recommended production deployment configuration. WARNING: Use CTRL-C to abort. Starting namenodes on [hadoop01] Starting datanodes Starting secondary namenodes [hadoop01] Starting resourcemanager Starting nodemanagers [hadoop@hadoop01 hadoop-3.2.0]$ jps 8497 NameNode 9121 ResourceManager 8868 SecondaryNameNode 9268 NodeManager 9630 Jps