# Installing Java 8
OpenBoxes with Grails 3 now require Java 8 - you must install a Java 8 JRE/JDK. Unfortunately, the APT Repository on Ubuntu 16.04 does not include a version
of the Java 8 JRE or JDK so we'll need to do some work to get this working. I would personally recommend
**Option 1** below.
!!! important
In case it wasn't clear from the box above this means you should NOT attempt to install the `default-jre`,
`openjdk-8-jre`, or `openjdk-9-jre` packages from the APT repository.
Grails 1.3.9 does not support Java 8+ so Tomcat will fail to deploy OpenBoxes.
When it fails, you will send an email to
[support@openboxes.com](mailto:support@openboxes.com) asking why the installation failed. When we receive your email,
we will point you back to the little blue box that you ignored. Don't be that person.
## Choose your choice
See the following [StackExchange question](https://askubuntu.com/questions/761127/how-do-i-install-openjdk-7-on-ubuntu-16-04-or-higher) for more details
* [Option 1: Install from Zulu Linux](https://askubuntu.com/a/840945) **(recommended)**
This seems like an ok option if you're comfortable manually install Debian packages - it's pretty straightforward.
* [Option 2: Automatic Installation](https://askubuntu.com/a/803616) **(no longer recommended)**
I would recommend this solution. It's a little more complex but seems to behave as you'd expect when installing
from the APT repository.
* [Option 3: Manual Installation](https://askubuntu.com/a/803616) **(not recommended)** You can certainly use this solution, but I had some trouble getting it to work so I would not recommend it. See
* [Option 4: Oracle Java](https://askubuntu.com/a/761527) **(not not recommended)**[^1]
This would probably be a recommended option, but Oracle ended public support for JDK 7 along time ago.
* [Option 5: Install from an unsupported package maintainer](https://askubuntu.com/a/761527) **(not recommended)**
This is probably the easiest solution, but also the least secure. Your friends will call you names.
* [Option 6: Use docker](https://askubuntu.com/a/1059859) **(recommended)** I would recommend using docker, but unfortunately do not have any instructions to share at this time.
!!! danger
Do not use Option 5 in production. Do not use this solution unless you are in a rush and either plan to do it
properly when you have time or you plan to throw away this server after evaluating OpenBoxes.
[^1]: You read that correctly. I wrote "not not recommended", which is a double negative meaning
"we're not recommending it, but we're also not not recommending it."
## Option 1: Zulu Linux
We're going to go with Option 1 since it appears the be the most straightforward approach at this point in time.
1. Go to
1. Click on Downloads > Zulu Community
1. Locate the Zulu Community Linux Repositories section
1. Click the Apt-get link
1. Follow the instructions (the instructions below might not match what you see so please follow the instructions yourself)
For example, here's what I had to do to install Zulu JDK 8 on Ubuntu 18.04
```
$ sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 0xB1998361219BD9C9
$ sudo apt-add-repository 'deb http://repos.azulsystems.com/ubuntu stable main'
$ sudo apt-get update
$ sudo apt-get install zulu-8
```
## Configure Java version
```
$ sudo update-alternatives --config java
```
If there's more than one JRE on the system then you'll be prompted to choose one.
```
There are 5 choices for the alternative java (providing /usr/bin/java).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 auto mode
1 /usr/lib/jvm/java-11-openjdk-amd64/bin/java 1111 manual mode
2 /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java 1071 manual mode
3 /usr/lib/jvm/java-7-oracle/jre/bin/java 1073 manual mode
* 4 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java 1081 manual mode
5 /usr/lib/jvm/java-9-openjdk-amd64/bin/java 1091 manual mode
Press to keep the current choice[*], or type selection number:
```
If there's only one you'll see a message like this:
```
There is only one alternative in link group java (providing /usr/bin/java): /usr/lib/jvm/zulu-8-amd64/jre/bin/java
Nothing to configure.
```
## Check Java version
```
$ java -version
```
You should see output similar to the following
```
openjdk version "1.8.0_292"
OpenJDK Runtime Environment (build 1.8.0_292-8u292-b10-0ubuntu1~16.04.1-b10)
OpenJDK 64-Bit Server VM (build 25.292-b10, mixed mode)
```