How to Uninstall (Oracle Java & openJDK) in Linux

Most of us believe that uninstalling Java is a difficult task in Linux, but it’s not as per my opinion, because I have installed Java on various distributions several times and removed it safely without any problems.

To do so, you need to check few things before removing JAVA.

In general, people install ‘Oracle Java’ or ‘openJDK’ depending on their need.

In this guide, we will show you how to uninstall/remove Java in Linux. By looking at the steps below, you will realize how easy it is.

Why should we remove Java?

You may need to uninstall Java from your system for below common reasons:

• You may need to install latest version due to application compatibility.
• You no longer need Java on your system

Refer the below link for installing Java on various Linux distributions.

• How to install Oracle Java or OpenJDK in Linux

1) Checking current version of Java

Installed Java version in Linux system can be verified using the following command. The below output shows that we have Oracle Java version “1.7.0_72” :

$ java -version
java version "1.7.0_72"
Java(TM) SE Runtime Environment (build 1.7.0_72-b14)
Java HotSpot(TM) 64-Bit Server VM (build 24.72-b04, mixed mode)

2) Check if you have installed any other Java version

For various reasons, some users might have installed multiple Java versions which can all be listed together using the 'update-alternatives' command as shown below.

As per the following output, we have installed three Java versions and ‘Oracle Java 7’ is the one that’s currently active on the system:

$ sudo update-alternatives --config java
There are 3 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-oracle/jre/bin/java          1072      auto mode
  1            /opt/jdk1.8.0_20/bin/java                        2         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          1072      manual mode

Press enter to keep the current choice[*], or type selection number:

3) Checking Java installation method

Before uninstalling Java, you should find how Java was installed in the system. It could be installed using one of the below methods:

• Manual method
• From the rpm file
• Distribution repository or Third-party repository

As stated in the beginning of the article, user would have installed Oracle Java or openJDK.

• OpenJDK : Everybody uses distribution official repository to install openJDK.
• Oracle JAVA : User might use one of these methods viz. Manual or Third-party repository or RPM file.

3.a) Checking Java installation method on Debian/Ubuntu

Use the below commands to check how JAVA was installed on an Ubuntu/Debian system. As per the below output, “OpenJDK 1.7.0_65” has been installed from the Ubuntu repository:

$ java -version
java version "1.7.0_65"
OpenJDK Runtime Environment (IcedTea 2.5.3) (7u71-2.5.3-0ubuntu1)
OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)

Feel free to double check whether “OpenJDK 1.7.0_65” was installed from the Ubuntu repository by running the below command, which in our case shows that it was installed from the Ubuntu official repository as shown below:

$ dpkg -l | grep openjdk
ii  openjdk-7-jdk:amd64                      7u71-2.5.3-0ubuntu1            amd64        OpenJDK Development Kit (JDK)
ii  openjdk-7-jre:amd64                      7u71-2.5.3-0ubuntu1            amd64        OpenJDK Java runtime, using Hotspot JIT
ii  openjdk-7-jre-headless:amd64             7u71-2.5.3-0ubuntu1            amd64        OpenJDK Java runtime, using Hotspot JIT (headless)

As per the below output, “Oracle Java 7” has been installed from third-party repository, namely "webupd8" :

$ dpkg -l | grep oracle-java
ii  oracle-java7-installer                7u72+7u60arm-0~webupd8~2       all      Oracle Java(TM) Development Kit (JDK) 7

Also, we can see that “Oracle JAVA 8” was installed using the manual method, as it is located under the ‘/opt’ directory, see below:

$ sudo update-alternatives --config java
  Selection    Path                                            Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-oracle/jre/bin/java          1072      auto mode
  1            /opt/jdk1.8.0_20/bin/java                        2         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          1072      manual mode

3.b) Checking Java installation method on RPM based systems

Use the below commands to find out how JAVA was installed on RPM based systems, such as RHEL, CentOS, Fedora and openSUSE. The following output shows that, “OpenJDK 1.7.0_71” was installed using the CentOS repository:

$ java -version
java version "1.7.0_71"
OpenJDK Runtime Environment (rhel-2.5.3.2.el6_6-x86_64 u71-b14)
OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)

You can double check the above result by running the below command:

$ rpm -qa | grep java
java-1.7.0-openjdk-1.7.0.71-2.5.3.2.el6_6.x86_64

Also, the “Oracle Java 8” was installed manually using the RPM file as per the following output, because it doesn’t show the distribution version which was shown in the previous output:

$ rpm -qa | grep jdk
jdk1.8.0_25-1.8.0_25-fcs.x86_64

4) Removing Java in Linux

Now that we have understood how to find out the installation method of JAVA on a Linux system, let’s proceed to understand how to remove/uninstall JAVA.

Uninstalling Oracle Java or openJDK can be done in multiple ways and you can use a suitable method as you see fit. This section summarizes some of those methods.

4.a) Removing Java in Debian/Ubuntu

You may need to run these commands based on section'3.a' to uninstall ‘Oracle Java’ or ‘OpenJDK’ in Ubuntu/Debian systems:

[To uninstall Openjdk 7]
$ sudo apt-get purge openjdk-7-*

[To remove Oracle Java 7]
$ sudo apt-get remove oracle-java7-installer

[To Uninstall Oracle Java 8]
$ cd /opt
$ sudo rm -Rf jdk1.8.0_20

4.b) Removing Java in RPM based system

You may need to run these commands based on section'3.b' to uninstall ‘Oracle Java’ or ‘OpenJDK’ in Red Hat, CentOS, Fedora and openSUSE systems:

[To Uninstall Openjdk]
$ rpm -e (grep output from 3b)
$ sudo rpm -e java-1.7.0-openjdk-1.7.0.71-2.5.3.2.el6_6.x86_64

[To Remove Oracle Java 8]
$ sudo rpm -e jdk1.8.0_25-1.8.0_25-fcs.x86_64

4.c) Uninstalling Oracle Java

Alternatively, Oracle Java can be removed from the Linux system using the ‘update-alternatives’ command as shown below.

(replace the word (version)with your Java version. DO java -version to get yours. So if your version is 1.8.0-92, you would type sudo update-alternatives –remove “java” “/usr/lib/jvm/jdk1.8.0-92/bin/java”)

$ sudo update-alternatives --remove "java" "/usr/lib/jvm/jdk[version]/bin/java"
$ sudo update-alternatives --remove "javac" "/usr/lib/jvm/jdk[version]/bin/javac"
$ sudo update-alternatives --remove "javaws" "/usr/lib/jvm/jdk[version]/bin/javaws"

Now, remove the corresponding JDK folder by executing the following command:

$ sudo rm -r /usr/lib/jvm/jdk[version]

5) Checking Java version

At this stage, we have completely removed openJDK & Oracle Java from our system. If no Java version is installed on the system, you will get the following message:

$ java -version
bash: /usr/bin/java: No such file or directory

Closing Notes

In this article, you learnt how to install ‘Oracle Java’ or ‘OpenJDK’ in various Linux distributions such as Ubuntu, Debian, RHEL, Fedora, CentOS and openSUSE.

If you found this article helpful, please do share with your friends and spread the knowledge. Please feel free to comment below if you have any queries/concerns. We will get back to you as soon as we can. Happy learning!