Develop Reference

JDK version 1.8 in the system but JDK 11 on VScode

I have JDK11 and JADK8 both installed on my MacOS. I have changed the JDK default version to 1.8 to make sure GlassFish V5 can be run.
However, the change is not taken place at VSCode, and VSCode terminal keeps on showing JDK11 as JAVA version, which is preventing me from running GlassFish server though VSCode.
How can I fix this?
Thank you

Here you can choose wich version to install.
Edit : as mentionned here
VS Code does not have built-in support for Java projects. You need to install some Java extensions and configure them to specify the correct Java JDK version, which you can do by either setting the JAVA_HOME environment variable or by setting the java.home setting:

It depends on the value of JAVA_HOME environment variable. Check your JAVA_HOME path in the settings.json file.
If it shows Java11, set JAVA_HOME environment variable as per your requirement and restart VSCode. Check How to set JAVA_HOME in Mac permanently?.

Java extension needs jdk11 or recent version to support, so it's required to set jdk11 as java.home in vscode, but it's also achievable to specify other jdk version for project.
Open Command Palette and Search Java: Configure Java Runtime.
Choose JDK8 for Project JDKs.
Choose JDK11 or recent version as
Java Tooling Time.
Don't forget to reload window to make the change effective.
Detailed information please view official docs: Configure JDK

JDK and JRE version confusion

I've been working with Java for a bit now and the JDK/JRE version has given me quite a bit of trouble lately. I am developing using the Intellij IDEA IDE and it of course uses the latest version of the JDK, 14. However when I attempt to execute software compiled with JDK 14 outside the IDE, I get an error that the JRE isn't new enough to run this software. So I updated Java on my computer and another machine and attempt to run again without any success. After some digging, I tweaked my machine to use the JRE included in the JDK 14 which is compatible.
However it is kind of odd that I had to do that, one would think that the latest version of java should of been enough to run applications made with the latest version of the JDK (14). Right now Java is version 8 build 251 and says there is no newer update available. If JDK 14 is out for a while now, why would they not update the version of Java they ship?
The problem is partially solved, as only the machine I am using for development is capable of executing the created applications. Other people I've sent them to have been unable to run them, despite having the latest version of java. Also it is a pain to get the latest JDK, especially when having limited experience on how to get rid of old versions, change path point to the latest version, get the right package (open/oracle JDK) and do that for windows and several distrubutions of linux. What is going on? Did I get Java from the wrong place and everyone else as well? Why are oracle doing this and why are there no java updates since clearly there exists a newer version?

Starting with Java-11, separate JRE does not exist anymore. In other words, if you are using Java-11 or above, you should care about JDK only.
You should uninstall JRE-8 from your machine and make sure your JDK-14 bin folder in the PATH variable. Some application even requires JAVA_HOME to work and therefore you should make sure that your system has an environment variable called JAVA_HOME and its value set to the root folder of JDK-14 (i.e. one level above your JDK bin).
Q: What should my clients do to run my application compiled on JDK-14?
Ans: Your clients must install JDK-14. Also, check this thread for some alternatives.

You're confusing how IntelliJ or JDK are used on the OS. IntelliJ, now, often comes with its JDK binaries (but even this can be configured, IntelliJ can be configured to use any JDK/JRE build you'll provide to it); however, if you run your Java application out of IntelliJ, most likely you're using Java installed locally on your OS, which might be referenced via your JAVA_HOME environment variable.
I'd suggest to:
Check java -version in your shell (and hence you'll see what JVM instance your OS spins up when you run a Java application);
Check where java (on Windows, or which - on Linux) in your shell, to see all the Java binaries available on your OS.

Try to uninstall Java SE Development Kit and Java JRE(if you have both in your machine) and reinstall both again, JDK and JRE both, I am sharing my google drive link where you can find the latest version of both JDK and JRE and when you are done installing, add there bin folder path in the Environment Variables of your machine.

Tizen Install on Windows 10 will not recognize JDK 9 installed

I am attempting to install the 64-bit version of Tizen SDK on my Win10 Home Laptop. However, every time I get the error that I either don't have java 8+ installed or that the JAVA_HOME environmental variable isn't set right.
Now I've read other questions on this, and I've set the JDK directory as first in the "Path" environmental variable. I've added the JAVA_HOME environ. var and pointed it at my JDK directory. I've rebooted twice throughout this (just in case).
I tried to install the 32-bit version of Tizen SDK, but immediately got the error that I'm not on a 32-bit OS.
I have d/l and installed Java 9 SDK and JRE. They're in
C:\Program Files\Java\jdk-9 &
C:\Program Files\Java\jre-9 respectively.
Here's my Path variable:
Path Variable Image
Any help would be mucho appreciated!

Response on Oct, 2017:
** So far Tizen studio installer can't recognize new version of Java. **
You need to install Oracle Java 8 for now.
Additional Checklist:
[✔] Tizen developers site states "Do not install OpenJDK". Make sure you are using OracleJDK instead of OpenJDK. Related links you might see:
Forum Post
[✔] There's a Tip&Tech document on Tizen Developers
Community called 'Guide for Setting JDK'. As you are having Issues, You may check it out.
Tizen: Guide for Setting JDK
[✔] I expect you are using the Latest Tizen Studio 2.0.
Latest Tizen Studio Download Link
Cause history says, Java compatibility Defers with IDE versions:
Tizen-sdk-for-wearable-setup Installation issue because of JAVA HOME
Edit on March, 2019:
Tizen-Studio now supports OpenJDK 10
To use Tizen Studio install Oracle Java Development Kit (JDK) 8, JDK 9, or OpenJDK 10 .
Prerequisites for the Tizen Studio
OpenJDK 10 and OpenJFX Installation Guideline on Tizen Developers Site

I was stuck there for a while, too. In addition to setting JAVA_HOME to C:\Program Files\Java\jdk-12.0.1 (no bin at the end), I also added C:\Program Files\Java\jdk-12.0.1\bin to the beginning of PATH; then it worked.

I've had the same problem, therefore i installed JDK8 from oracle website and the installer works fine. (no need to reboot) If you don't need specific JDK9 stuff, go with 8 and you will be good to go. Don't forget to update JAVA_HOME and Path to point to JDK8.
I have set as user variables CLASSPATH set to C:\Program Files\Java\jre1.8.0_144\lib, JAVA_HOME set to C:\Program Files\Java\jdk1.8.0_144
As system variables i've added to the existing Path this value C:\Program Files\Java\jdk1.8.0_144\bin and JAVA_HOME the same as above (even though i'm not sure the latter one is required).
PS. I have both JDK8 and 9 installed and Windows 10 64bit. I tried installing Tizen on debian using JDK9 and i got the same error, i'm sure that using JDK8 will work (need to check installation on OSX though)
Cheers!

On my M1 Mac with macOS 12, I was having trouble getting the Tizen package manager to run. It kept giving me:
Java Development Kit (JDK) was not found on your computer. To use the Tizen Studio, you need to install the JDK 8 or later. Please go to http://www.oracle.com/technetwork/java/javase/downloads and download a JDK.
Deleting ~/.package-manager solved the issue.

In my case adding "C:\Program Files\Java\jdk-12.0.2\bin" (with the quotes) to the PATH did the trick, i.e. the installer run successfully

Information on the tizen website is incomplete. On Windows 10 using OpenJDK follow the article and you need to enter another environment and system parameters after adding Java_home.
Parameter is "PATH" value is "%JAVA_HOME%\bin" otherwise Tizen Studio installation wont recognize it.

I download the IDE of version 3.2 and install the open jdk10, IDE can load successfully, but load the emulator failed when click the tools -> emulator manager.
error: could not create the java virtual machine.
my setting:
path: %JAVA_HOME%\bin
JAVA_PATH: c\jdk-10
what's the problem here? please give some suggestions.

The only thing that worked for me in the end was:
Uninstall the recent Java version and install Java SE 8u231.
After that, I tried Tizen 1.3, and it worked.
I don't know if the newer versions works, but the above worked for me for now.

Can I have two versions of the JDK on my computer?

I'm trying to set the IntelliJ IDEA JDK to version 1.8 (because it's the latest). When I navigate to System/Library/Frameworks/JavaVM.framework IntelliJ IDEA shows 1.6. When I type java -version it shows 1.8. I found that command under "Finding default JDK on OSX" https://www.java.com/en/download/help/version_manual.xml
I'm confused what versions of the JDK I have... and where they are located. Appreciate any help.

Yes, you can. You have JDK 1.6 and 1.8 installed on your computer. According to the Jetbrains website, all their products require Apple JDK 1.6 to be installed in order to run on Mac.
To make IntelliJ IDEA use JDK 1.8, you will need to edit /Applications/<Product>.app/Contents/Info.plist file and change JVMVersion from 1.6* to 1.8* :
<key>JVMVersion</key>
<string>1.8*</string>

To start off java will usually uninstall any version of the JDK when you get an update. Secondly if you want to check to see what version you are running I would go into what ever you are using to program and see what version you are compiling under (For example netbeans or eclipse). If it says 1.8 that is what you are running and same for 1.6. If this is really becoming a super big problem all you have to is uninstall java then re install and it should fix it.

You can have many different versions of Java on your system. In general Java depends on environment variables and the PATH environment variable. Some programs and tools look for tool specific environment variables to allow you to use a specific version of Java for that particular tool.
In the case of IntellJ the link that Eddie B posted in his comment explains how IntellJ determines which "installation" of Java it should use.

ADT can't find installed JREs on Mac

I have ADT Installed. v23.0.2.
I tried to import simple java project, but found no installed JRE to compile the code. I then installed JDK & JRE from Java SE downloads. I yet don't see any JRE in the list. Anything am I missing? any hooks ?

If it does not find it "automagically" then you need to "Add" it or "Search" it. Most likely though, when you installed the JRE, it was not properly added to the "path" or another install problem.
See this post:
How to install JRE 1.7 on Mac OS X and use it with Eclipse?
Chances are "Search" will do what you need.