I am trying to learn MapReduce but I am a little lost right now.
Particularly this set of instructions:
Compile WordCount.java and create a jar:
$ bin/hadoop com.sun.tools.javac.Main WordCount.java
When I type in hadoop
in my terminal I am able to see the "Help" made which provides arguments so I believe I have hadoop installed.
When I type in the command:
Compile WordCount.java and create a jar:
hadoop com.sun.tools.javac.Main WordCount.java
I get the error:
Error: Could not find or load main class com.sun.tools.javac.Main
I know I have Java installed and working on my computer because I've used it before to create other programs.
This command outputs:
$ /usr/libexec/java_home
/Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home
Maybe I am missing a set of Java tools? Not sure
I got same error.
And i solved it by add HADOOP_CLASSPATH environment parameter:
export HADOOP_CLASSPATH=/usr/lib/jvm/java-7-openjdk-amd64/lib/tools.jar
Please make sure that you installed OpenJDK7. I am using Ubuntu 14.04:
sudo apt-get install openjdk-7-jdk