Wordcount示例hadoop(Wordcount example hadoop)

 我是Hadoop的新手，并试图通过其网站上提供的示例进行探索。因此，这听起来像是一个非常基本的问题。 
 
 在Eclipse IDE中，我简单地创建了一个java项目，导入了必要的hadoop jar和核心jar。 然后，我运行了一个可下载的WordCount示例，它可以成功运行。 
 
 但是，我没有设置任何Hadoop安装或单个节点群集。 
 
 因此，我无法弄清楚，即使没有在我的系统中配置hadoop，该作业如何运行。 
 
 我最初的理解是，我需要在Ubuntu Linux上安装像hadoop Hadoop这样的hadoop才能开始，但显然这不是必需的。 为什么？ 

I am new to Hadoop and trying to explore it via examples available on their website.So this might sound like a very basic question.
 
In Eclipse IDE I simply created a java project ,imported necessary hadoop jars and the core jar. I then ran a WordCount example that comes with downloadable and it ran successfully.
 
However, I didn't setup any Hadoop installation or a single node cluster.
 
Hence I am unable to figure out how can that job run even without hadoop being configured in my system.
 
My initial understanding was I will need to install hadoop following something like Running Hadoop on Ubuntu Linux to get going, but apparently that was not necessary. Why?

原文：https://stackoverflow.com/questions/32641683