Installing Java 7 on Ubuntu

Question

to install java I have always used the classic way from the terminal. I would like to install java manually. I placed the folder of the JDK on the desk and I set environment

Answer 1

I think you should consider Java installation procedure carefully. Following is the detailed process which covers almost all possible failures.

Installing Java with apt-get is easy. First, update the package index:

sudo apt-get update

Then, check if Java is not already installed:

java -version

If it returns "The program java can be found in the following packages", Java hasn't been installed yet, so execute the following command:

sudo apt-get install default-jre

You are fine till now as I assume.

This will install the Java Runtime Environment (JRE). If you instead need the Java Development Kit (JDK), which is usually needed to compile Java applications (for example Apache Ant, Apache Maven, Eclipse and IntelliJ IDEA execute the following command:

sudo apt-get install default-jdk

That is everything that is needed to install Java.

Installing OpenJDK 7:

To install OpenJDK 7, execute the following command:

sudo apt-get install openjdk-7-jre 

This will install the Java Runtime Environment (JRE). If you instead need the Java Development Kit (JDK), execute the following command:

sudo apt-get install openjdk-7-jdk

Installing Oracle JDK:

The Oracle JDK is the official JDK; however, it is no longer provided by Oracle as a default installation for Ubuntu.

You can still install it using apt-get. To install any version, first execute the following commands:

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

Then, depending on the version you want to install, execute one of the following commands:

Oracle JDK 7:

sudo apt-get install oracle-java7-installer

Oracle JDK 8:

sudo apt-get install oracle-java8-installer