Linux set default java version

How to set default java version in linux

Solution 2: If you want to change it globally and at system level; In add this line: Solution 3: to set Oracle’s Java SE Development Kit as the system default Java just download the latest Java SE Development Kit from here then create a directory somewhere you like in your file system for example now extract the files you just downloaded in that directory: now to set your environment variable: make sure the Oracle’s java is set as default java by: you get something like this: pay attention to the asterisk before the numbers on the left and if the correct one is not set choose the correct one by typing the number of it and pressing enter. now test your java: if you get something like the following, you are good to go: also note that you might need root permission or be in sudoers group to be able to do this. If you want to set environment variables globally and at system level means use should set in file.

How to set the default Java version

As per this answer: How to set default Java version?

Try providing the explicit path along with update-alternatives —install first, and then run update-alternatives to make your selection:

sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/java-7-oracle/jre/bin/java" 1 sudo update-alternatives --config java sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/java-7-oracle/bin/javac" 1 sudo update-alternatives --config javac 

You need to set javac too.

sudo update-alternatives --config javac 

I had the same problem. I had sun jdk6 installed. After

 sudo update-alternatives --config java sudo update-alternatives --config javac sudo update-alternatives --config javaws 

a restart was necessary for me. Than it worked.

Edit: I realized it was not enough to do the steps above.

I also had to edit the environment variable:

And add (a different java version will require a different string) :

 JAVA_HOME="/usr/lib/jvm/java-7-openjdk-amd64" 

CentOS7: Setting default JAVA as Oracle JDK and not openJDK, A simple approach would be to first remove Open JDK using purge then install Oracle jdk..if u are using apt-get it would automatically set

Change — switch java version in linux

Install Java/JDK Version 8, 11, 14 on Linux

This video tutorial will tell you how to install different Java or JDK version 8 or version 11 or
Duration: 12:49

Want to change default java version to 1.8.xx [duplicate]

Have you tried using update-java-alternatives instead of update-alternatives ?

Show the list of available alternatives:

sudo update-java-alternatives -l 

sudo update-java-alternatives -s java-1.8.0-openjdk-amd64 

Changing Default JDK On Ubuntu 20.10, I’m having trouble changing the default version of Java on Ubuntu 20.10. I want to change the default version of Java JDK from Graal to OpenJDK

How to set Oracle’s Java as the default Java in Ubuntu?

export JAVA_HOME=/usr/lib/jvm/java-7-oracle 

/usr/lib/jvm/java7-oracle should be a symbolic link pointing to /usr/lib/jvm/java-7-oracle-[version number here] .

The reason it’s a symbolic link is that in case there’s a new version of the JVM, you don’t need to update your .bashrc file, it should automatically point to the new version.

If you want to set JAVA_HOME environment variables globally and at system level means use should set in /etc/environment file.

If you want to change it globally and at system level;

JAVA_HOME=/usr/lib/jvm/java-7-oracle 

to set Oracle’s java se development kit as the system default Java just download the latest Java SE Development Kit from here then create a directory somewhere you like in your file system for example /usr/java now extract the files you just downloaded in that directory:

$ sudo tar xvzf jdk-8u5-linux-i586.tar.gz -C /usr/java 

now to set your JAVA_HOME environment variable:

$ JAVA_HOME=/usr/java/jdk1.8.0_05/ $ sudo update-alternatives --install /usr/bin/java java $/bin/java 20000 $ sudo update-alternatives --install /usr/bin/javac javac $/bin/javac 20000 

make sure the Oracle’s java is set as default java by:

$ update-alternatives --config java 

you get something like this:

There are 2 choices for the alternative java (providing /usr/bin/java). Selection Path Priority Status ------------------------------------------------------------ * 0 /opt/java/jdk1.8.0_05/bin/java 20000 auto mode 1 /opt/java/jdk1.8.0_05/bin/java 20000 manual mode 2 /usr/lib/jvm/java-6-openjdk-i386/jre/bin/java 1061 manual mode Press enter to keep the current choice[*], or type selection number: 

pay attention to the asterisk before the numbers on the left and if the correct one is not set choose the correct one by typing the number of it and pressing enter. now test your java:

if you get something like the following, you are good to go:

java version "1.8.0_05" Java(TM) SE Runtime Environment (build 1.8.0_05-b13) Java HotSpot(TM) Server VM (build 25.5-b02, mixed mode) 

also note that you might need root permission or be in sudoers group to be able to do this. I’ve tested this solution on both ubuntu 12.04 and Debian wheezy and it works in both of them.

How to switch between different java versions in Linux?, And you can install different-different Java versions using sdk install command e.g. $ sdk install java 9.0.4-open $ sdk install java

Getting different default java versions for different users in linux

It is quite trivial. Add this to the user .bashrc file

export JAVA_HOME=/path/to/javaXYZdir export PATH=$/bin:$PATH 

This assumes user shell is bash.

How to set JAVA_HOME in Linux for all users, Open terminal and type sudo gedit .bashrc · It will ask you your password. After typing the password, it will open the bash file. Then go to end and type: export

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Change default Java version in Ubuntu 20.04 LTS

We consider this article to be an extension to the previous article – Install OpenJDK JRE / JDK in Ubuntu 20.04 LTS . As you would notice, we have already installed version 11 of OpenJDK JRE / JDK in Ubuntu 20.04 LTS release. Now, consider a scenario wherein we have also installed version 8 of OpenJDK JRE. In that case, the default version would still be the one which we have installed earlier i.e. version 11.0.7. So, in this article we would discuss how to change the default Java version in Ubuntu 20.04 LTS.

Just for clarity, we would first install OpenJDK Development Kit v11.0.7 and OpenJDK Java Runtime Environment v1.0.8_252. Thereafter, we would issue the specific command to change the default version of Java.

Note: Following operations would require you to have superuser privileges. In case you don’t have one, then contact your System Administrator for assistance.

Install different versions of OpenJDK Development Kit and Java Runtime Environment

Since the packages are already available in standard Ubuntu repository. Therefore, first update the Ubuntu repository to make the latest version of the package available. Hence, issue the following in terminal –

Now, to install OpenJDK Development Kit v11.0.7 –

sudo apt install openjdk-11-jdk

Next, to install OpenJDK Java Runtime Environment v1.8.0_252 –

sudo apt install openjdk-8-jre

Change default Java version in Ubuntu 20.04 LTS

First, verify for the Java version installed –

It would return the output –

openjdk version "11.0.7" 2020-04-14 OpenJDK Runtime Environment (build 11.0.7+10-post-Ubuntu-3ubuntu1) OpenJDK 64-Bit Server VM (build 11.0.7+10-post-Ubuntu-3ubuntu1, mixed mode, sharing)

Although we already installed version 1.8.0_252, But, when we pass the java -version command then it doesn’t mention the said version. Because, as of now v11.0.7 is the default version. To change that, we need to issue command –

sudo update-alternatives --config java

It would show us all the Java versions installed. Enter the selection number for OpenJDK JRE v1.8.0_252. Again –

This time it would return with –

openjdk version "1.8.0_252" OpenJDK Runtime Environment (build 1.8.0_252-8u252-b09-1ubuntu1-b09) OpenJDK 64-Bit Server VM (build 25.252-b09, mixed mode)

In conclusion, we have discussed how to change the default version of Java in Ubuntu 20.04 LTS release.

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How to change the default Java version on Ubuntu

If you are a Java developer, it is normal to have multiple Java versions installed on your machine to support different build environments. When a Java program is compiled, the build environment sets the oldest JRE version the program can support. Now, if you run this program on a Linux machine where an unsupported Java version is installed, you will encounter an exception.

For example, if your program is compiled on Java 11, it can’t be run on a machine where Java 8 is installed. But the good thing is you can install multiple Java versions on your machine and quickly change the default JRE version.

In this tutorial, I’ll explain how to change the default Java version on a Linux machine. First of all, run the following command to check the current Java version:

$ java -version openjdk version "1.8.0_191" OpenJDK Runtime Environment (build 1.8.0_191-8u191-b12-2ubuntu0.18.10.1-b12) OpenJDK 64-Bit Server VM (build 25.191-b12, mixed mode) 

As you can see above, the default Java version is currently set to OpenJDK JRE 1.8. Now, let’s run the following command to see all available Java versions:

$ sudo update-alternatives --config java 

Running the above command displays a list of installed Java JDKs and JREs allowing you to select the one as you want to set as default.

There are 2 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-8-openjdk-amd64/jre/bin/java 1081 manual mode Press enter> to keep the current choice[*], or type selection number: 

When prompted, select the Java version you would like to use. If the list does not include your desired Java version, you can always install it.

Now you can verify the default Java version as fellows:

$ java -version openjdk version "11.0.2" 2019-01-15 OpenJDK Runtime Environment (build 11.0.2+9-Ubuntu-3ubuntu118.10.3) OpenJDK 64-Bit Server VM (build 11.0.2+9-Ubuntu-3ubuntu118.10.3, mixed mode, sharing) 

That’s it. The default Java version is changed to OpenJDK 11.

If you frequently switch between different Java versions, it is a good idea to write a short script to automate the process. Here is the script I used for switching to OpenJDK 8 on my machine. java8.sh

sudo update-java-alternatives -s java-1.8.0-openjdk-amd64 export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-amd64/ export PATH=$PATH:$JAVA_HOME 

Similarly, you can create scripts for other Java versions installed on your machine. The next step is to add these scripts as aliases to .bashrc file.

... # Java Alias alias java8='source /opt/java/switch/java8.sh' alias java11='source /opt/java/switch/java11.sh' 

Read Next: How to install Java on Ubuntu 18.04 ✌️ Like this article? Follow me on Twitter and LinkedIn. You can also subscribe to RSS Feed.

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