无法将 JAVA 路径更改为 Oracle JDK

Question

I'm using RHEL8 which has default OpenJDK installed. which java command points to /usr/bin/java. java -version gives openjdk version "1.8.0_252"

Installed java in /u01/app/java/ location. Modified the.bashrc like below & sourced it. export JAVA_HOME=/u01/app/java/jdk1.8.0_241/ PATH="$JAVA_HOME/bin/java:$HOME/.local/bin:$HOME/bin:$PATH" export PATH

Now JAVA_HOME points to /u01/app/java/jdk1.8.0_241/ But which java or java -version still points to the OpenJDK.

• Added the same in.bash_profile file & removed it from the.bashrc: Results are same
• Deleted OpenJDK & made changes in.bash_profile. But by doing so ended up with "Command not found" error.

How can i fix it?

Answer 1

It was Path issue. I have given PATH="$JAVA_HOME/bin/java:$HOME/.local/bin:$HOME/bin:$PATH" for PATH. which should not be the case. Modified my PATH to below. It worked.

PATH="$JAVA_HOME/bin:$HOME/.local/bin:$HOME/bin:$PATH" export PATH

Answer 2

That happens because when you invoke java it is actually invoked /usr/bin/java , which, issuing ls -l /usr/bin/java you will probably see is linked to the openjdk installation (probably through a double link: the first one being /usr/bin/java to /etc/alternatives/java and the second one being the link to the "real" java executable). For example, on my debian:

gianluca@asus-debian:~$ ls -l /usr/bin/java
lrwxrwxrwx 1 root root 22 mag 20  2018 /usr/bin/java -> /etc/alternatives/java
gianluca@asus-debian:~$ ls -l /etc/alternatives/java
lrwxrwxrwx 1 root root 43 nov 22  2019 /etc/alternatives/java -> /usr/lib/jvm/java-11-openjdk-amd64/bin/java

You can fix in two ways:

• Dirty way, you manually update all the symbolic links in /usr/bin that lead to the unwanted java version and make them point to the desired one
• Clean way, you use alternatives that does the job for you.

You can read more about alternatives for RHEL here (mid-page... "The longer version").

Good link