Posts Tagged With ‘java&8217


How To Install Apache Tomcat 8 on Ubuntu without using apt-get

Sometimes you would want to install the latest version of tomcat server but your using apt-get doesn’t work for you. I had to go this route when my IntelliJIDEA IDE didn’t like my apt-get way installed tomcat server.

Before trying below make sure you have java installed and system variable JAVA_HOME has been set properly.

Step 1 : Get the latest version of tomcat server
wget http://mirror.atlanticmetro.net/apache/tomcat/tomcat-8/v8.0.0-RC10/bin/apache-tomcat-8.0.0-RC10.tar.gz

Note: Change the file url and file name based on what is latest available by looking into following URL:
http://mirror.atlanticmetro.net/apache/tomcat

Step 2 : Unzip tomcat installation files
tar xzvf apache-tomcat-8.0.0-RC10.tar.gz
sudo mv apache-tomcat-8.0.0-RC10 /usr/local
Step 3 : Setup system variable
nano ~/.bashrc

this will open up a text editor. Go to the end of the file (Alt+/) and add the following line:

export CATALINA_HOME=/usr/local/apache-tomcat-8.0.0-RC10

save and exit (Crlt+X and Y)

Step 4 : Load new configuration
. ~/.bashrc

Step 5 : Test your setup
Start tomcat server

sudo $CATALINA_HOME/bin/startup.sh

Then open this URL in your browser

http://localhost:8080

If everything is alright, you would see tomcat’s webapp GUI.


Java Quick-facts

Java is an island in Indonesia to the south of Borneo; one of the world’s most densely populated regions.

However, we would focus here more on Java Programming language than the Island or the delicious coffee from that island.

Java is pioneer in Object Oriented Programming methodology.

Java treats every ‘object’ as an object in real world. Or, to put more clearly, mimic each and every process as close to real world. For example: air, wind are objects with peculiar property of their own.

As SCJP guide puts:

A Java program is mostly a collection of objects talking to other objects by invoking each other’s methods. Every object is of a certain type, and that type is defined by a class or an interface. Most Java programs use a collection of objects of many different types.

Class: A template that describes the kinds of state and behavior that objects of its type support.

Object: At runtime, when the Java Virtual Machine (JVM) encounters the new keyword, it will use the appropriate class to make an object which is an instance of that class. That object will have its own state, and access to all of the behaviors defined by its class.

State: (instance variables) Each object (instance of a class) will have its own unique set of instance variables as defined in the class. Collectively, the values assigned to an object’s instance variables make up the object’s state.

Behavior: (methods) When a programmer creates a class, she creates methods for that class. Methods are where the class’ logic is stored. Methods are where the real work gets done. They are where algorithms get executed, and data gets manipulated.