Where do I download all of the necessary classes to write Hadoop MapReduce jobs?

Question

I've recently started working with Hadoop and have been learning how to write MapReduce jobs. All over the internet, I can find examples and tutorials for writing MapReduce jobs, but they all include import statements that go something like 'import org.apache.hadoop.util.*;'. I cannot find where to download any of those classes and I can't even begin writing jobs until I do find them. Where can I download the necessary plug-in?

I've tried the plug-in that comes along with a Hadoop download and I've also tried a MapReduce plug-in for Eclipse distributed by IBM, but neither has worked. Where can I download the correct one?

Thanks!

Solution 1

I assume you're using java...

Here you can download it. http://hadoop.apache.org/common/releases.html#Download

If you're on 20.X, you'll just need to import (putting it into your classpath) the hadoop-0.20.X-core.jar in the "root" folder. If > 20.X you have to use three jars: hadoop-common-0.21.0.jar, hadoop-hdfs-0.21.0.jar, hadoop-mapred-0.21.0.

Obviously you have to replace the 'x' with the suffix of the version you're using.

Solution 2

You can use Maven repositories for that. I'm assuming you are using Java and Maven.
Repos are here: https://repository.cloudera.com/index.html