The priority given for java and javac (given at the end of bothh command lines above) may not
set it as the default version.
# update-alternatives --display java
java - auto mode
link currently points to /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
/opt/local/jdk-1.8.0_51/bin/java - priority 100
/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java - priority 1071
slave java.1.gz: /usr/lib/jvm/java-7-openjdk-amd64/jre/man/man1/java.1.gz
Current 'best' version is '/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java'.
Set the installed version as the default:
# update-alternatives --config java
There are 2 choices for the alternative java (providing /usr/bin/java).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java 1071 auto mode
1 /opt/local/jdk-1.8.0_51/bin/java 100 manual mode
2 /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java 1071 manual mode
Press enter to keep the current choice[*], or type selection number: 1
update-alternatives: using /opt/local/jdk-1.8.0_51/bin/java to provide /usr/bin/java (java) in manual mode
Test the installed version
# ls -l /etc/alternatives/java
lrwxrwxrwx 1 root root 32 Aug 10 14:29 /etc/alternatives/java -> /opt/local/jdk-1.8.0_51/bin/java
# update-alternatives --display java
java - manual mode
link currently points to /opt/local/jdk-1.8.0_51/bin/java
/opt/local/jdk-1.8.0_51/bin/java - priority 100
/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java - priority 1071
slave java.1.gz: /usr/lib/jvm/java-7-openjdk-amd64/jre/man/man1/java.1.gz
Current 'best' version is '/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java'.
# java -version
java version "1.8.0_51"
Java(TM) SE Runtime Environment (build 1.8.0_51-b16)
Java HotSpot(TM) 64-Bit Server VM (build 25.51-b03, mixed mode)
set the environment variables for Java
Add the follwing line to
JAVA_HOME="/opt/local/jdk-1.8.0_51"
after that, run
source /etc/environment
and verify that the environment var has been issued: