Setting the JAVA_HOME environment variable in Ubuntu

Question

I'm pretty new on ubuntu, at some point in the terminal I'm running: ``` mortar local:illustrate pigscripts/retail-recsys.pig purchase_input -f params/retail.params ``` but I have this following error: A suitable java installation could not be found. If you already have java installed please set your JAVA_HOME environment variable before continuing. Otherwise, a suitable java installation will need to be added to your local system. Installing Java On OSX run `javac` from the command line. This will intiate the installation. For Linux systems please consult the documentation on your relevant package manager. But I'm pretty sure I have Java, so please how can I set my JAVA_HOME environment variable?

Accepted Answer

First, you need to decide which installed version of Java to use? No fear, you can pick any you have -

```
update-java-alternatives -l
```

One "easy" solution is to add this to "$HOME/.bashrc",

```
export JAVA_HOME=$(update-java-alternatives -l | head -n 1 | awk -F ' ' '{print $NF}')
```

This picks the first installed JDK and takes it's JAVA_HOME (the third field) - on my system that's

```
/usr/lib/jvm/java-1.7.0-openjdk-amd64
```

Setting the JAVA_HOME environment variable in Ubuntu

Solution

Problem