[Java] Install Java (JDK/JRE) on CentOS/RHEL

Download Latest Java Archive

Official download page : http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

• 64Bit 다운로드, 압축해제
  

$ cd /opt/

$ 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/8u91-b14/jdk-8u91-linux-x64.tar.gz"

$ tar xzf jdk-8u91-linux-x64.tar.gz

Java설치 / 기본 JDK변경

alternatives 명령어 : 여러 버전의 JDK가 설치 되어 있을때 기본 JDK를 변경해 주는 명령어

$ cd /opt/jdk1.8.0_91/

$ alternatives --install /usr/bin/java java /opt/jdk1.8.0_91/bin/java 2

$ alternatives --config java

There are 3 programs which provide 'java'.

Selection Command

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

* 1 /opt/jdk1.7.0_71/bin/java

+ 2 /opt/jdk1.8.0_45/bin/java

3 /opt/jdk1.8.0_77/bin/java

4 /opt/jdk1.8.0_91/bin/java

Enter to keep the current selection[+], or type selection number: 4

• javac와 jar 명령어 경로를 대체해준다
  

$ alternatives --install /usr/bin/jar jar /opt/jdk1.8.0_91/bin/jar 2

$ alternatives --install /usr/bin/javac javac /opt/jdk1.8.0_91/bin/javac 2

$ alternatives --set jar /opt/jdk1.8.0_91/bin/jar

$ alternatives --set javac /opt/jdk1.8.0_91/bin/javac

설치된 Jave 버전 확인

• 시스템에서 사용되는 java 버전 확인
  

$ java -version

java version "1.8.0_91"

Java(TM) SE Runtime Environment (build 1.8.0_91-b14)

Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode)

환경 변수 변경

• Setup JAVA_HOME, JRE_HOME, PATH variable

$ export JAVA_HOME=/opt/jdk1.8.0_91

$ export JRE_HOME=/opt/jdk1.8.0_91/jre

$ export PATH=$PATH:/opt/jdk1.8.0_91/bin:/opt/jdk1.8.0_91/jre/bin

/etc/enviroment 파일에 환경 변수 내용이 추가되면 system이 부팅될때 자동으로 로딩됨