Because of the different Linux developers, so different developers of Linux version operation details are not the same, today, the installation of CentOS under the JDK:
Method One: Manually unzip the JDK's tarball and set the environment variable
1. Create a Java directory under the/usr/directory
[Email protected] ~]# Mkdir/usr/java
[Email protected] ~]# Cd/usr/java
2. Download the JDK, then unzip
[Email protected] java]# Curl-o http://download.Oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.tar.gz
[Email protected] java]# TAR-ZXVF jdk-7u79-linux-x64.tar.gz
3. Setting Environment variables
[Email protected] java]# Vi/etc/profile
In profile, add the following:
#set Java Environment
java_home=/usr/java/jdk1.7.0_79
Jre_home=/usr/java/jdk1.7.0_79/jre
Class_path=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar: $JRE _home/lib
Path= $PATH: $JAVA _home/bin: $JRE _home/bin
Export Java_home jre_home Class_path PATH
Let the changes take effect:
[Email protected] java]# Source/etc/profile
4. Verifying JDK Validity
[Email protected] java]# java-version
Java Version "1.7.0_79"
Java (TM) SE Runtime Environment (build 1.7.0_79-b15)
Java HotSpot (TM) 64-bit Server VM (build 24.79-b02, Mixed mode)
Method Two: Install the JDK with Yum
1. See which JDK versions are available in the Yum Library (OPENJDK only)
[email protected] ~]# Yum search Java|grep JDK
Ldapjdk-javadoc.x86_64:javadoc for LDAPJDK
JAVA-1.6.0-OPENJDK.X86_64:OPENJDK Runtime Environment
JAVA-1.6.0-OPENJDK-DEMO.X86_64:OPENJDK Demos
JAVA-1.6.0-OPENJDK-DEVEL.X86_64:OPENJDK Development environment
JAVA-1.6.0-OPENJDK-JAVADOC.X86_64:OPENJDK API Documentation
JAVA-1.6.0-OPENJDK-SRC.X86_64:OPENJDK Source Bundle
JAVA-1.7.0-OPENJDK.X86_64:OPENJDK Runtime Environment
JAVA-1.7.0-OPENJDK-DEMO.X86_64:OPENJDK Demos
JAVA-1.7.0-OPENJDK-DEVEL.X86_64:OPENJDK Development environment
JAVA-1.7.0-OPENJDK-JAVADOC.NOARCH:OPENJDK API Documentation
JAVA-1.7.0-OPENJDK-SRC.X86_64:OPENJDK Source Bundle
JAVA-1.8.0-OPENJDK.X86_64:OPENJDK Runtime Environment
JAVA-1.8.0-OPENJDK-DEMO.X86_64:OPENJDK Demos
JAVA-1.8.0-OPENJDK-DEVEL.X86_64:OPENJDK Development environment
JAVA-1.8.0-OPENJDK-HEADLESS.X86_64:OPENJDK Runtime Environment
JAVA-1.8.0-OPENJDK-JAVADOC.NOARCH:OPENJDK API Documentation
JAVA-1.8.0-OPENJDK-SRC.X86_64:OPENJDK Source Bundle
Ldapjdk.x86_64:The Mozilla LDAP Java SDK
2. Select a version to install
Select version 1.7 to install
[email protected] ~]# Yum install JAVA-1.7.0-OPENJDK
After the installation is complete, the default installation directory is:/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.75.x86_64
3. Setting Environment variables
[Email protected] ~]# Vi/etc/profile
Add the following content to the profile file
#set Java Environment
Java_home=/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.75.x86_64
Jre_home= $JAVA _home/jre
Class_path=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar: $JRE _home/lib
Path= $PATH: $JAVA _home/bin: $JRE _home/bin
Export Java_home jre_home Class_path PATH
Let the changes take effect
[Email protected] java]# Source/etc/profile
4. Verification (Ibid. method)
Method Three: Install the JDK with rpm
1. Download RPM installation files
[Email protected] ~]$ Curl-o http://download.oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.rpm
2. Installing using the RPM command
[Email protected] ~]# RPM-IVH jdk-7u79-linux-x64.rpm
3. Setting Environment variables
[Email protected] java]# Vi/etc/profile
Add the following in the open profile file
#set Java Environment
java_home=/usr/java/jdk1.7.0_79
Jre_home=/usr/java/jdk1.7.0_79/jre
Class_path=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar: $JRE _home/lib
Path= $PATH: $JAVA _home/bin: $JRE _home/bin
Export Java_home jre_home Class_path PATH
Let the changes take effect
[Email protected] java]# Source/etc/profile
4. Verification (Ibid. method)
Note: Similar to yum installation, you can run Java commands without setting environment variables. The RPM installation method installs the JDK to/usr/java/jdk1.7.0_79 by default, and then links to/usr/bin via a three-layer link, as follows:
[[email protected] ~]# cd/bin
[[email protected] bin]# ll|grep java
lrwxrwxrwx. 1 root root & nbsp Mar 11:24 jar->/usr/java/default/bin/jar
lrwxrwxrwx. 1 root root April-11:24 Java-/usr /java/default/bin/java
lrwxrwxrwx. 1 root root April 11:24 Javac->/usr/java/default/bin/javac
lrwxrwxrwx. 1 root root Mar 11:24 javadoc->/usr/java/default/bin/javadoc
lrwxrwxrwx. 1 root root Mar 11:24 javaws->/usr/java/default/bin/javaws
lrwxrwxrwx. 1 root root April 11:24 Jcontrol->/usr/java/default/bin/jcontrol
[[email protected] bin]# cd/usr/java/
[[Email protected] java]# ll
Total 4
lrwxrwxrwx. 1 root root -April 11:24 default->/usr/java/latest
Dr Wxr-xr-x. 8 root root 4096 Mar 11:24 jdk1.7.0_79
lrwxrwxrwx. 1 root root April 11:24 Latest _79
Method Four: Install JDK on Ubuntu using Apt-get
1. See which JDK versions are available in the APT library
[Email protected]:~# apt-cache Search Java|grep JDK
Default-jdk-standard Java or Java compatible development Kit
Default-jdk-doc-standard Java or Java Compatible development Kit (documentation)
GCJ-4.6-JDK-GCJ and Classpath development tools for Java (TM)
GCJ-JDK-GCJ and Classpath development tools for Java (TM)
Openjdk-6-dbg-java runtime based on OPENJDK (debugging symbols)
Openjdk-6-demo-java runtime based on OPENJDK (demos and examples)
OPENJDK-6-DOC-OPENJDK Development Kit (JDK) documentation
OPENJDK-6-JDK-OPENJDK Development Kit (JDK)
OPENJDK-6-JRE-LIB-OPENJDK Java Runtime (architecture Independent libraries)
OPENJDK-6-SOURCE-OPENJDK Development Kit (JDK) source files
Openjdk-7-dbg-java runtime based on OPENJDK (debugging symbols)
Openjdk-7-demo-java runtime based on OPENJDK (demos and examples)
OPENJDK-7-DOC-OPENJDK Development Kit (JDK) documentation
OPENJDK-7-JDK-OPENJDK Development Kit (JDK)
OPENJDK-7-SOURCE-OPENJDK Development Kit (JDK) source files
Uwsgi-plugin-jvm-openjdk-6-Java plugin for UWSGI (OPENJDK 6)
Uwsgi-plugin-jwsgi-openjdk-6-Jwsgi plugin for UWSGI (OPENJDK 6)
OPENJDK-6-JRE-OPENJDK Java Runtime, using Hotspot JIT
OPENJDK-6-JRE-HEADLESS-OPENJDK Java Runtime, using Hotspot JIT (headless)
OPENJDK-7-JRE-OPENJDK Java Runtime, using Hotspot JIT
OPENJDK-7-JRE-HEADLESS-OPENJDK Java Runtime, using Hotspot JIT (headless)
OPENJDK-7-JRE-LIB-OPENJDK Java Runtime (architecture Independent libraries)
2. Select a version to install
[Email protected]:~# apt-get Install OPENJDK-7-JDK
3. Setting Environment variables
[Email protected]:~# vi/etc/profile
Add the following in the open profile file
#set Java Environment
Java_home=/usr/lib/jvm/java-1.7.0-openjdk-amd64
Jre_home= $JAVA _home/jre
Class_path=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar: $JRE _home/lib
Path= $PATH: $JAVA _home/bin: $JRE _home/bin
Export Java_home jre_home Class_path PATH
Let the changes take effect
[Email protected]:~# source/etc/profile
4. Verification (Ibid. method)
Linux installation JDK