CentOS Install JDK

Method One: Manual decompression JDK , and then 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, 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

Add the following content:

#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

[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: with Yum Installing the JDK (CentOS)

1. See which jdk versions are available in the Yum Library

[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

we install here 1.7 version

[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:

#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

3. Verification

Ibid.

Note: because of the adoption of Yum Span class= "S1" > install jdk , the system takes into account multiple versions of the issue, using the Alternatives for version control. Start, the corresponding version of jdk installed in /usr/lib/jvm/ , it is registered in alternatives , in /etc/alternatives The directory will produce some links to /usr/lib/jvm/ just installed jdk version.

in the /usr/bin the corresponding files that are linked to/etc/alternatives are shown below . For example,/usr/bin will have a link file below The Java mapping relationship as follows:

/usr/bin/java->/etc/alternatives/java

/etc/alternatives/java->/usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java

this way, the Java command does not have to set the environment variable, it can run normally. However, if you want to set environment variables for Tomcat or other software.

Similarly, if you install a new version jdk, it will be re-linked to the latest installed jdk version. Of course, you can also use alternatives to modify the version you want to use.

specific methods can be referred to: Managing multiple versions of software using Linux alternatives

method Three: with rpm installation JDK

1. Download

[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

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

1:JDK ###########################################[100%]

Unpacking JAR files ...

Rt.jar ...

Jsse.jar ...

Charsets.jar ...

Tools.jar ...

Localedata.jar ...

Jfxrt.jar ...

3. setting environment variables

[Email protected] java]# Vi/etc/profile

Add the following content:

#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

[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)

and the similar to yum installation, you can run Java commands without setting an environment variable . the rpm installation method installs the JDK to the /usr/java/jdk1.7.0_79 by default , and then link to it through the three-layer links /usr/bin, the specific link is as follows:

[Email protected] ~]# Cd/bin

[Email protected] bin]# ll|grep java

lrwxrwxrwx. 1 root root Mar 11:24 jar->/usr/java/default/bin/jar

lrwxrwxrwx. 1 root root 11:24 java-/usr/java/default/bin/java

lrwxrwxrwx. 1 root root 11:24 javac->/usr/java/default/bin/javac

lrwxrwxrwx. 1 root root 11:24 javadoc->/usr/java/default/bin/javadoc

lrwxrwxrwx. 1 root root 11:24 javaws->/usr/java/default/bin/javaws

lrwxrwxrwx. 1 root root 11:24 jcontrol->/usr/java/default/bin/jcontrol

[Email protected] bin]# cd/usr/java/

[email protected] java]# LL

Total 4

lrwxrwxrwx. 1 root root 11:24 default->/usr/java/latest

Drwxr-xr-x. 8 root root 4096 Mar 11:24 jdk1.7.0_79

lrwxrwxrwx. 1 root root 11:24 latest-/usr/java/jdk1.7.0_79

method Four: Ubuntu Installing the JDK 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 content:

#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

[Email protected]:~# java-version

Java Version "1.7.0_79"

OpenJDK Runtime Environment (IcedTea 2.5.5) (7u79-2.5.5-0ubuntu0.12.04.1)

OpenJDK 64-bit Server VM (build 24.79-b02, Mixed mode)

Ubuntu of the apt-get is installed in a similar way to the yum installation of CentOS and is no longer verbose here.

CentOS Install JDK