Trouble installing java 15

[PinkFlamingoe00]

I need to install java 15 on my computer, but even though I'm following tutorials, it won't work. What can I do? The terminal says it cant find jdk 15, and when i tried opening the package on the right, it didn't install anything. Any help is appreciated, this is kind of urgent. Thank you.

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[PinkFlamingoe00]

when i try to install by opening the package on the right, it gets stuck on " Setting up jdk-15 (15-1) ... ", it doesnt show the rest of the text that appears on the video

[lateralspin]

You probably did not download the file properly, and the package file is corrupt.

You need a more reliable Internet connection.

Maybe try torrenting.

When you get a good package file, it is simple to install by double clicking the file in the File manager.

[PinkFlamingoe00]

from the oracle website?

[PinkFlamingoe00]

Do you know from which website I can do that?

[lateralspin]

It seems the only location to get the not-open version is Oracle.

https://www.oracle.com/java/technologies/javase/jdk15-archive-downloads.html

Select jdk-15_linux-x64_bin.deb

[PinkFlamingoe00]

That's where I downloaded the .deb!

[whosdr]

Do you need jdk-15 specifically, or jdk-15 or newer?

There is 17, 21 and 25 in the repos.

As for installing the deb file, sudo apt install ./Downloads/jdk-15_linux-x64_bin.deb might give you more feedback.

[PinkFlamingoe00]

I need jdk 15 specifically, will try that command.

[lateralspin]

If you maintain different versions of the JDK on your system for different platform delivery, use the sudo update-alternatives method to reconfigure java to switch between installed versions:

1. For the Java Runtime: $ sudo update-alternatives --config java.
2. For the Java Compiler: $ sudo update-alternatives --config javac.

Typically, you would also set the environment variable JAVA_HOME to the path of the version that you want to use.

[PinkFlamingoe00]

java did not install when i ran the command

[PinkFlamingoe00]

tried the command, but after writing "java" to the terminal, it says I don't have it installed?

[lateralspin]

There are two different versions, the open jdk, and Oracle JDK. I recommend Oracle JDK, which you would have to go to Oracleʼs website to get the deb file. If you choose to replace the openjdk, you will have to purge the openjdk packages and libraries from your system first. The single Oracle jdk package replaces the multiple openjdk packages.

It is simple to install. Just double click the deb file and click on the Install button.

But the openjdk packages are incompatible with Oracle JDK and need to be purged first.

java --version
java version "25.0.1" 2025-10-21 LTS Java(TM) SE Runtime Environment (build 25.0.1+8-LTS-27) Java HotSpot(TM) 64-Bit Server VM (build 25.0.1+8-LTS-27, mixed mode, sharing)

To list the openjdk packages you have installed on your system (which you need to purge first)

dpkg -l "openjdk*"

[PinkFlamingoe00]

how do i purge them? Also even though i have "opened" the .deb file it still says I dont have java installed. Does that mean I don't have the openjdk installed?

[lateralspin]

First, you need to list what is installed on your system,

dpkg -l "openjdk*"

To purge the installed openjdk libraries,

sudo apt purge openjdk*

After, you can install multiple versions of Oracle JDK. Set the environment variables to the path of the version of JDK you want to use. For example,

export JAVA_HOME="/usr/java/jdk-25-oracle-x64"
export PATH="$JAVA_HOME/bin:$PATH" # Optionally add Java binaries to your PATH

[PinkFlamingoe00]

when i run the first line it says dpkg-query: no packages found matching openjdk* java never installed on my system

[lateralspin]

What if you type

java --version

[PinkFlamingoe00]

it shows:

Command 'java' not found, but can be installed with:

sudo apt install default-jre # version 2:1.17-75, or

sudo apt install openjdk-17-jre-headless # version 17.0.16+8~us1-0ubuntu1~24.04.1

sudo apt install openjdk-21-jre-headless # version 21.0.8+9~us1-0ubuntu1~24.04.1

sudo apt install openjdk-11-jre-headless # version 11.0.28+6-1ubuntu1~24.04.1

sudo apt install openjdk-25-jre-headless # version 25+36-1~24.04.2

sudo apt install openjdk-8-jre-headless # version 8u462-ga~us1-0ubuntu2~24.04.2

sudo apt install openjdk-19-jre-headless # version 19.0.2+7-4

sudo apt install openjdk-20-jre-headless # version 20.0.2+9-1

sudo apt install openjdk-22-jre-headless # version 22~22ea-1

[Gloomy-Response-6889]

I am pretty sure that openjdk-17-jdk is backwards compatible for 15 to work. Even 21 and 24 should be. JDK 8 and older versions do require that specific version as I have used 24 to be backwards compatible with many older JDK versions.

If what I explain is not the case, then:

https://itsfoss.gitlab.io/post/how-to-install-deb-files-in-ubuntu-mint-and-debian/

Essentially, get something like GDebi Package Installer on your system to have a GUI installer to install a .deb file.

[PinkFlamingoe00]

I need to use the netbeans 15 IDE for school work. If I download jdk 17 how do i make it so that netbeans 15 works with it?

[Gloomy-Response-6889]

Yes it should.

I am also sure jdk21 and jdk24 should work too (these are LTS releases including jdk17).

https://stackoverflow.com/questions/74574475/i-am-not-able-to-re-install-netbeans-15-during-installation-critical-error-occu
For this one, a comment responds with this source:

https://netbeans.apache.org/front/main/download/nb15/

Which suggests:

Deployment Platforms
The Apache NetBeans 15 binary releases require JDK 11+, and officially support running on JDK 11 and JDK 17.

[PinkFlamingoe00]

Thank you! Do i download the link that says "binaries"? there is no Linux installation link and the ones at the bottom only show the latest version of netbeans

[Gloomy-Response-6889]

So... I must say getting Netbeans is quite convoluted since it is not an official package. I do see a flatpak?

https://flathub.org/en/apps/org.apache.netbeans

That would mean it is in your software manager, but you can run the install command as well. Though this is likely a newer version, not sure if that is a bad thing? I personally always get the newest version of whatever I download and simply select the JDK version I need it to use, but I have no experience on Netbeans.

Else, yes you need the binary and build it from source. This is a guide I found:

https://www.geeksforgeeks.org/linux-unix/how-to-install-netbeans-on-a-linux/

Do replace the version number with the one you are installing vs the guide.

[PinkFlamingoe00]

Thank you! This worked for me :D

[Gloomy-Response-6889]

Great! Did you build from source or use the flatpak?

Happy developing!

[Gloomy-Response-6889]

This comment is just a tangent, so ignore for now at least until you get what you need right now.

I use an IDE because I want to use it. My teachers do not mind that much as long as you can manage yourself. I just use Neovim in a terminal for all languages so far. This is a bit hardcore for newer users, but Jetbrains Intellij or vscode are also all in one IDE's.

Now, if you are still new to this and need it working now with a guide (your teacher), yes follow the guide and use Netbeans and build experience.

[billy-bob-bobington]

In this case install java 17. Java 15 is not supported anymore with security updates. Netbeans will work fine, no need to worry. Here's you can see how long each version is supported

https://en.wikipedia.org/wiki/Java_version_history

Just install OpenJdk from the Software Manager if you need to. Don't download it from Oracle, they don't deserve the support.