resolve different java and javac version in ubuntu-CodePudding

My java --version gives:

openjdk 11.0.13 2021-10-19
OpenJDK Runtime Environment (build 11.0.13 8-Ubuntu-0ubuntu1.21.10)
OpenJDK 64-Bit Server VM (build 11.0.13 8-Ubuntu-0ubuntu1.21.10, mixed mode, sharing)

But when I do: javac --version I get:

javac 17

whereis java gives:

java: /usr/bin/java /usr/share/java /opt/jdk-17/bin/java /usr/share/man/man1/java.1.gz

As far as I can remember I downloaded openjdk 17 from the official site and followed official documentation.

I usually work with maven projects and I just noticed this issue. Haven't created any problem so far. But I would like to resolve it. Is it possible to do so without removing java and reinstalling?

Update:

echo $PATH
/home/arnob/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/snap/bin:/opt/jdk-17/bin:/home/arnob/sdks/flutter/bin:/opt/maven/bin:/home/arnob/.local/bin:/home/arnob/.pub-cache/bin:/usr/lib/postgres/13/bin

And

ls -l /usr/bin/java

lrwxrwxrwx 1 root root 22 Dec 19 00:58 /usr/bin/java -> /etc/alternatives/java

CodePudding user response：

In your bashrc, for example, seems like you're adding /opt/jdk-17/bin to the PATH, but at the end, not before /usr/bin/, and you have Java 11 JRE installed separately, so it gets picked up first

You should fix this by reversing it

export JAVA_HOME=/opt/jdk-17
export PATH="${JAVA_HOME}/bin;$PATH"

I suggest doing the same thing for flutter, maven, Postgres, etc

CodePudding user response：

Run the below commands in your terminal and choose the default java and javac version. You needn't uninstall anything.

update-alternatives --config java
update-alternatives --config javac