Three ways to install JDK under CentOS

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

mkdir/usr/~]# Cd/usr/java

2. Download the JDK, then unzip

[Email protected] java]# Curl-o http://tar -zxvf jdk-7u79-linux-x64. tar. gz

3. Setting Environment variables

VI /etc/profile

In profile, add the following:

#set java environmentjava_home=/usr/java/jdk1. 7 . 0_79jre_home=/usr/java/jdk1. 7. 0_79/Jreclass_path=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar: $JRE _home/LibPATH = $PATH: $JAVA _home/bin: $JRE _home/binexport 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-"1.7.0_79"1.7. 0_79-   - 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] ~]#YumSearch java|grepJDKLDAPJDK-javadoc.x86_64:javadoc forLdapjdkjava-1.6.0-Openjdk.x86_64:OpenJDK Runtime Environmentjava-1.6.0-openjdk-Demo.x86_64:OpenJDK Demosjava-1.6.0-openjdk-Devel.x86_64:OpenJDK Development Environmentjava-1.6.0-openjdk-Javadoc.x86_64:OpenJDK API Documentationjava-1.6.0-openjdk-Src.x86_64:OpenJDK Source Bundlejava-1.7.0-Openjdk.x86_64:OpenJDK Runtime Environmentjava-1.7.0-openjdk-Demo.x86_64:OpenJDK Demosjava-1.7.0-openjdk-Devel.x86_64:OpenJDK Development Environmentjava-1.7.0-openjdk-Javadoc.noarch:OpenJDK API Documentationjava-1.7.0-openjdk-Src.x86_64:OpenJDK Source Bundlejava-1.8.0-Openjdk.x86_64:OpenJDK Runtime Environmentjava-1.8.0-openjdk-Demo.x86_64:OpenJDK Demosjava-1.8.0-openjdk-Devel.x86_64:OpenJDK Development Environmentjava-1.8.0-openjdk-Headless.x86_64:OpenJDK Runtime Environmentjava-1.8.0-openjdk-Javadoc.noarch:OpenJDK API Documentationjava-1.8.0-openjdk-Src.x86_64:OpenJDK Source Bundleldapjdk.x86_64:The Mozilla LDAP Java SDK

2. Select a version to install

// Select version 1.7 to install 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

VI /etc/profile

Add the following content to the profile file

#set java environmentjava_home=/usr/lib/jvm/java-1.7. 0-openjdk-1.7. 0.75 . X86_64jre_home= $JAVA _home/jreclass_path=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar:$ jre_home/LibPATH= $PATH: $JAVA _home/bin: $JRE _home/binexport 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

VI /etc/profile

Add the following in the open profile file

#set java environmentjava_home=/usr/java/jdk1. 7 . 0_79jre_home=/usr/java/jdk1. 7. 0_79/Jreclass_path=.: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar: $JRE _home/LibPATH = $PATH: $JAVA _home/bin: $JRE _home/binexport 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|grepjavalrwxrwxrwx.1Root root -Mar -  One: -Jar->/usr/java/default/bin/jarlrwxrwxrwx.1Root root -Mar -  One: -Java-/usr/java/default/bin/javalrwxrwxrwx.1Root root -Mar -  One: -Javac->/usr/java/default/bin/javaclrwxrwxrwx.1Root root inMar -  One: -Javadoc->/usr/java/default/bin/javadoclrwxrwxrwx.1Root root -Mar -  One: -Javaws->/usr/java/default/bin/javawslrwxrwxrwx.1Root root -Mar -  One: -Jcontrol->/usr/java/default/bin/Jcontrol[[email protected] bin]# CD/usr/java/[email protected] java]# lltotal4lrwxrwxrwx.1Root root -Mar -  One: -Default->/usr/java/LATESTDRWXR-xr-x.8Root root4096Mar -  One: -Jdk1.7. 0_79lrwxrwxrwx.1Root root +Mar -  One: -Latest,/usr/java/jdk1.7.0_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|grepJdkdefault-JDK-Standard Java or Java compatible development Kitdefault-jdk-doc-Standard Java or Java Compatible development Kit (documentation) GCJ-4.6-JDK-GCJ and Classpath Development tools forJava (TM) gcj-JDK-GCJ and Classpath Development tools forJava (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) documentationopenjdk-6-JDK-OpenJDK Development Kit (JDK) OpenJDK-6-jre-lib-OpenJDK Java Runtime (architecture Independent libraries) OpenJDK-6-source-OpenJDK Development Kit (JDK) source Filesopenjdk-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) documentationopenjdk-7-JDK-OpenJDK Development Kit (JDK) OpenJDK-7-source-OpenJDK Development Kit (JDK) source Filesuwsgi-plugin-jvm-openjdk-6-Java Plugin forUwsgi (OpenJDK6) Uwsgi-plugin-jwsgi-openjdk-6-Jwsgi Plugin forUwsgi (OpenJDK6) OpenJDK-6-JRE-OpenJDK Java Runtime, using Hotspot jitopenjdk-6-jre-headless-OpenJDK Java Runtime, using Hotspot JIT (headless) OpenJDK-7-JRE-OpenJDK Java Runtime, using Hotspot jitopenjdk-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

Install openjdk-7-jdk

3. Setting Environment variables

VI /etc/profile

Add the following in the open profile file

#set java environmentjava_home=/usr/lib/jvm/java-1.7. 0-openjdk-amd64jre_home= $JAVA _home/jreclass_path=.: $JAVA _home/lib/dt.jar: $JAVA _home /lib/tools.jar: $JRE _home/LibPATH= $PATH: $JAVA _home/bin: $JRE _home/binexport java_homejre_home Class_ Path Path

Let the changes take effect

[Email protected]:~# source/etc/profile

4. Verification (Ibid. method)

Three ways to install JDK under CentOS