A Java Development Kit (JDK) is a program development environment it’s released by Oracle Corporation. This binary package used for compile java application, debug, run  Java applets and applications.

We can install Java 7 (JDK 7u60) or Java 8 (JDK 8u25) in CentOS, Fedora, RHEL and other Linux related operating system.

This post describe install JDK 8u25 with 64 bit

Step 1: Download the packages as you like java 7 or java 8,

# mkdir /opt/java

# cd /opt/java

For JDK 7u60 64 Bit:


$ wget --no-check-certificate --no-cookies - --header "Cookie: oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/7u67-b01/jdk-7u67-linux-i586.tar.gz"



$ wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/7u60-b19/jdk-7u60-linux-i586.rpm"


For JDK 7u60 32 Bit:



$   wget --no-check-certificate --no-cookies - --header "Cookie: oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/7u67-b01/jdk-7u67-linux-i586.tar.gz"



$  wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/7u60-b19/jdk-7u60-linux-i586.rpm" 


For JDK 8u25 64 Bit:



$ wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/8u25-b17/jdk-8u25-linux-x64.tar.gz"



$ wget --no-check-certificate --no-cookies --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u65-b17/jdk-8u65-linux-x64.rpm


For JDK 8u25 32 Bit:



$  wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/8u25-b17/jdk-8u25-linux-i586.tar.gz"



$  wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" "http://download.oracle.com/otn-pub/java/jdk/8u25-b17/jdk-8u25-linux-i586.rpm"


Step 2: Install tar.gz file

If you have download the file with tar.gz format just extact under /opt or  /usr/java directories For example,
 
# mkdir /usr/java

# tar -xf jdk-8u25-linux-x64.tar.gz

# mv  jdk1.8.0_25   /usr/java/.


Step 3: Install RPM

Note : If you have downloaded RPM package follow below step,

Install Java 7  .rpm package,
 
# rpm -ivh jdk-7u60-linux-x64.rpm


Preparing...     ############### [100%]

   1:jdk          ############### [100%]

Unpacking JAR files...

    rt.jar...

    jsse.jar...

    charsets.jar...

    tools.jar...

    localedata.jar...

    jfxrt.jar...

Set JAVA_HOME path,
 
# export JAVA_HOME=/usr/java/jdk1.7.0_60

# export JRE_HOME=/usr/java/jdk1.7.0_60/jre

# export PATH=$PATH:/usr/java/jdk1.7.0_60/bin:/usr/java/jdk1.7.0_60/bin

You can check the path,
 
# echo $JAVA_HOME
/usr/java/jdk1.7.0_60

# echo $JRE_HOME
/usr/java/jdk1.7.0_60/jre

# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:.....

Install Java 8 package using alternatives command,
 
# alternatives --install /usr/bin/java java /opt/jdk1.8.0_25/bin/java 2

# alternatives --config java


There are 2 programs which provide 'java'.



  Selection    Command

-----------------------------------------------

*+ 1           /opt/jdk1.7.0_67/bin/java

   2           /opt/jdk1.8.0_25/bin/java



Enter to keep the current selection[+], or type selection number: 2

Check your Java Version
 
# java -version


java version "1.8.0_25"

Java(TM) SE Runtime Environment (build 1.8.0_25-b17)

Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)

Find Java installed location:
 
# whereis java


java: /usr/bin/java /opt/jdk1.8.0_25/bin/java

The Java 8 has been installed successfully installed in your system.


Step 4 : Additional setup:

Now, we need to setup javac and jar commands path using same command,
 
# alternatives --install /usr/bin/jar jar /opt/jdk1.8.0_25/bin/jar 2

# alternatives --install /usr/bin/javac javac /opt/jdk1.8.0_25/bin/javac 2

# alternatives --set jar /opt/jdk1.8.0_25/bin/jar

# alternatives --set javac /opt/jdk1.8.0_25/bin/javac


Step 5: Setup JAVA_Home path:
 
# JAVA_HOME=/opt/jdk1.8.0_25

# export JAVA_HOME

# PATH=$JAVA_HOME/bin:$PATH

# export PATH

Another option is,
 
# export JAVA_HOME=/opt/jdk1.8.0_25

#  export JRE_HOME=/opt/jdk1.8.0_25/jre

# export PATH=$PATH:/opt/jdk1.8.0_25/bin:/opt/jdk1.8.0_25/jre/bin

Check your $JAVA_HOME path,
 
# echo $JAVA_HOME 


/opt/jdk1.8.0_25