Install JDK Ubuntu

1.Installing JDK on Ubuntu 14.04

  OpenJDK or Oracle JDK

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Before we begin let makr sure that the server is fully updated with this following command:

     sudo apt-get update

After your server have been fully updated, you will need to know what version of Java is currently installed or if it is not installed ,with the following command:

   java -version

Once you have verified if Java is installed or not , choose the type of Java installation that you want with one the following:

   # open-jdk
   
   sudo apt-get install default-jdk
   sudo apt-get install default-jre

2.Install Java Open JRE or JDK on Ubuntu 14.04

   sudo apt-get install openjdk-7-jre
   sudo apt-get install openjdk-7-jdk

3.Install Java Oracle JRE or JDK on Ubuntu 14.04 (use ppa)

Another alternative Java install is with Oracle JRE and JDK. However , we would need additional repositories for a proper installation.

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

Then , you will need to fully update the system with the following command:

   sudo apt-get update

jdk installer list

   #  You can also install previous and newer versions of Java by using one of the following command:
   sudo apt-get install oracle-java6-installer
   sudo apt-get install oracle-java7-installer
   sudo apt-get install oracle-java8-installer

If you have multiple versions of Java installed on your server,then you have the ability to select a default version. Check your alternatives with the following command:

  sudo update-alternatives --config java

启动图片

4.Setup JAVA_HOME on Ubuntu 14.04

Since many programs now days need a JAVA_HOME environment variable

   JAVA_HOME="/usr/ib/jvm/java-8-oracle"