java 7 installation in ubuntu 14.04

I try to install jdk1.7.0_79 in ubuntu 14.04 First I download jdk1.7.0_79 Zip File.Then extact file and put it into download folder.

Then I create a directory like this

sudo mkdir /usr/lib/jvm

Then move jdk1.7.0_11 into the /usr/lib/jvm

sudo mv /Downloads/jdk1.7.0_79 /usr/lib/jvm

Then install file into followng step

sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.7.0_79/bin/javac"

This similar to both javac and javaws installation. Then I try

computerlabug@computerlab:/usr/bin$ java -version
bash: /usr/bin/java: No such file or directory 

And Configure as follows

computerlabug@computerlab:/usr/bin$ sudo update-alternatives --config java 

There are 2 choices for the alternative java (providing /usr/bin/java).

 Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/lib/jvm/jdk1.7.0_79/bin/java 2 auto mode 1 /usr/lib/jvm/jdk1.7.0_79/bin//java 1 manual mode 2 /usr/lib/jvm/jdk1.7.0_79/bin/java 2 manual mode
Press enter to keep the current choice[*], or type selection number: 

This is similar to javac and javaws

Then check java -version

computerlabug@computerlab:/usr/bin$ java -version
bash: /usr/bin/java: No such file or directory** 

What I do please explain step by step

2 Answers

Your mistake is in the update-alternatives command.

It should be

sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.7.0_79/jre/bin/java" 1

You've missed jre

Your javac command seem to be OK.

But the javaws is also

sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jdk1.7.0_79/jre/bin/javaws" 1

To fix it run

sudo update-alternatives --remove-all java
sudo update-alternatives --remove-all javaws
sudo update-alternatives --remove-all javac
sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.7.0_79/jre/bin/java" 1
sudo update-alternatives --install "/usr/bin/javaws" "javaws" "/usr/lib/jvm/jdk1.7.0_79/jre/bin/javaws" 1
sudo update-alternatives --install "/usr/bin/javac" "javac" "/usr/lib/jvm/jdk1.7.0_79/bin/javac" 1

Why not install it the easy way?

This method install Java JDK, JRE and the Java browser plugin:

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java7-installer

To check if the installation worked, enter the following command:

java -version