ubuntu——How to Install Oracle Java JDK8

haoman

• 　　Check to see if your Ubuntu Linux operating system
  architecture is 32-bit or 64-bit, open up a terminal and run the
  following command below.   
  　　
  　　
  
  
  
  • uname -a or file /sbin/init
    
  
  

　　Linux caochu-Inspiron-N5110 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Check if you have Java installed on your system. To do this, you will have to run the Java version command from terminal.

• Type/Copy/Paste:java -versio　　If you have OpenJDK installed on your system, you have the wrong vendor version of Java installed for this exercise.
  
  
• sudo apt-get purge openjdk-*
  

Download the Oracle Java JDK for Linux.

• 　　Unpack the compressed Java binaries, in the directory /usr/local/java8
  

Scroll down to the end of the file using your arrow keys and add the following lines below to the end of your./etc/profile file:

• export JAVA_HOME=/usr/local/java8/jdk1.8.0_73
  export JRE_HOME=${JAVA_HOME}/jre  
  export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib  
  export PATH=${JAVA_HOME}/bin:$PATH
  
• source /etc/profile
  

Configure default JDK version :

• 　　sudo update-alternatives --install /usr/bin/java  java  /usr/local/java8/jdk1.8.0_73/bin/java      300
  sudo update-alternatives --install /usr/bin/javac javac /usr/local/java8/jdk1.8.0_73/bin/javac    300
  sudo update-alternatives --install /usr/bin/jar   jar   /usr/local/java8/jdk1.8.0_73/bin/jar 300
  sudo update-alternatives --install /usr/bin/javah javah /usr/local/java8/jdk1.8.0_73/bin/javah  300
    sudo update-alternatives --install /usr/bin/javap javap /usr/local/java8/jdk1.8.0_73/bin/javap 300
  
• 　　sudo update-alternatives --config java
  

Test

• java -version