Javac is not same version as java

Question

Linux Mint 19.3

In file etc/profile:

export PATH=$PATH:$JAVA_HOME/bin

run set in terminal:

JAVA_HOME=/usr/java/jdk1.8.0_251
PATH=/usr/java/jdk1.8.0_251/bin

In terminal run

java -version

java version "1.8.0_251"
Java(TM) SE Runtime Environment (build 1.8.0_251-b08)
Java HotSpot(TM) 64-Bit Server VM (build 25.251-b08, mixed mode)

It's correct.

But when I run

javac -version I get another version.

javac 11.0.7

I need javac to be version 1.8 (same as java)

Answer 1

Root cause of the problem is due to JAVA_HOME being added at the end of the PATH.

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The problem can be fixed by adding JAVA_HOME to beginning of PATH, as follows:

export PATH=$JAVA_HOME/bin:$PATH

Working example:

Suppose that JDK 11 is installed in /opt/jdk-11 directory. Here are the steps to use java version 11 for both java and javac:

1. Update JAVA_HOME and PATH

export JAVA_HOME=/opt/jdk-11
export PATH=$JAVA_HOME/bin:$PATH

2. Verify that both java and javac are picked from /opt/jdk-11/bin

$ which java
/opt/jdk-11/bin/java

$ which javac
/opt/jdk-11/bin/javac

3. Verify the output of java and javac

$ java -version
java version "11.0.7" 2020-04-14 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.7+8-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.7+8-LTS, mixed mode)

$ javac -version
javac 11.0.7