如何在CentOS/RHEL和Fedora中安装 Java 8（JDK/JRE8u91）

Downloading Latest Java Archive

Download latest Java SE Development Kit 8 release from its official download page or use following commands to download from shell.

For 64Bit

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

For 32Bit

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-i586.tar.gz"

tar xzf jdk-8u91-linux-i586.tar.gz

Install Java with Alternatives

After extracting archive file use alternatives command to install it. alternatives command is available in chkconfig package.

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/jdk1.8.0_91/bin/java

Enter to keep the current selection[+], or type selection number: 1

At this point JAVA 8 has been successfully installed on your system. We also recommend to setup javac and jar commands path using alternatives

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

Check Installed Java Version

Check the installed Java version on your system using following command.

root@yusky ~# 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)

Configuring Environment Variables

Most of Java based application’s uses environment variables to work. Set the Java environment variables using following commands

Setup JAVA_HOME Variable

export JAVA_HOME=/opt/jdk1.8.0_91

Setup JRE_HOME Variable

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

Setup PATH Variable

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

Also put all above environment variables in /etc/environment file for auto loading on system boot.

Note：-bash: /usr/bin/java: cannot execute binary file 显示这个的话是安装的版本与系统版本不符.