Do you need to install Oracle's Java? Cuz if you don't need you can just open a terminal and type sudo apt install default-jre -y and it's ready to use (if you're on debian-based distros) More on reddit.com

Both rpm and dpkg systems typically use the "alternatives" system to support multiple installs of packages like java, so you can find yours like so: $ which java /usr/bin/java $ ls -l /usr/bin/java lrwxrwxrwx. 1 root root 22 Jan 29 15:08 /usr/bin/java -> /etc/alternatives/java* $ ls -l /etc/alternatives/java lrwxrwxrwx. 1 root root 72 Jan 29 15:08 /etc/alternatives/java -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.191.b13-0.fc29.x86_64/jre/bin/java* My install of Java is in /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.191.b13-0.fc29.x86_64 More on reddit.com

Please ensure that: Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions You include any and all error messages in full You ask clear questions You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions. Trying to solve problems on your own is a very important skill. Also, see Learn to help yourself in the sidebar If any of the above points is not met, your post can and will be removed without further warning. Code is to be formatted as code block (old reddit: empty line before the code, each code line indented by 4 spaces, new reddit: https://i.imgur.com/EJ7tqek.png ) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc. Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit. Code blocks look like this: public class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } } You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above. If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures. To potential helpers Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns. More on reddit.com

Java is a write once, run anywhere language, meaning you don't need anything special other than the JDK and a Linux compatible IDE.

For the JDK you can either use OpenJDK (An opensource implementation of Java / JDK) or Oracle's JDK (Original and most used JDK). OpenJDK is easily available through sources like Ubuntu's Software Centre whereas Oracle's JDK is a bit more painful to install (Depending on the distro), but this is a great resource to make it easier (For Debian based systems like Ubuntu).

As for an IDE you're already on the right track. Both Eclipse and IntelliJ are great options and have cross-platform support.

More on reddit.com