error in setting java home environment variables ubuntu

Question

i am new to ubuntu .initially i installed java in Ubuntu. But i haven't set any envionment variables

After that installed maven build tool to build java package.when i compiled with build tool it shows some error says generic supports after 1.3 packages.

so i realize it JDK runs with 1.3. so i need set java environment variables for latest version

so in my Terminal java -version shows

beeshma@ubuntu:~$ java -version
java version "1.7.0_45"
Java(TM) SE Runtime Environment (build 1.7.0_45-b18)
Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

and i set java environment variables in through below steps [ https://askubuntu.com/questions/277806/how-to-set-java-home][1]

sudo gedit ~/.bashrc

Now go to end of file and add the following lines:

export JAVA_HOME=/path/to/jdk/folder
#usually /usr/java/jdk or /usr/lib/java/jdk
export PATH=$PATH:$JAVA_HOME/bin

Now in terminal type:

sudo source ~/.bashrc

This will make it appear on every terminal if open.

Now you can cross check it by typing following line in terminal

$echo $PATH

/usr/java/jdk1.7.0_45//bin:/home/beeshma/bin:/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/usr/java/jdk1.7.0_45//bin

What my question when i execute mvn --help Fallowing error is coming

beeshma@ubuntu:~$ mvn -version
Error: JAVA_HOME is not defined correctly.
**We cannot execute /usr/java/jdk1.7.0_45//bin/java**

Answer 1

Two things:

• Try if /usr/java/jdk1.7.0_45//bin/java is indeed present.
• See if the beeshma user has the permissions to 'execute' java.
• Bonus: remove the trailing / in your JAVA_HOME value.

Answer 2

Try changing your export to:

export JAVA_HOME=$(/usr/java/jdk1.7.0_45)

Answer 3

You can install the JDK with the following command:

$sudo apt install default-jdk

The above command also sets the java environment variable automatically