Three methods for installing JDK under CentOS: centosjdk

Three methods for installing JDK under CentOS: centosjdk

Because of the differences between Linux development vendors, the operating details of Linux versions vary with development vendors. Today, let's talk about how to install JDK in CentOS:

Method 1: manually decompress the JDK compressed package and set the environment variable

1. Create a java directory under the/usr/directory

[root@localhost ~]# mkdir/usr/java[root@localhost ~]# cd /usr/java

2. Download jdk and decompress it.

[root@localhost java]# curl -O http://download.oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.tar.gz [root@localhost java]# tar -zxvf jdk-7u79-linux-x64.tar.gz

3. Set Environment Variables

[root@localhost java]# vi /etc/profile

Add the following content to profile:

#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

Make the modification take effect:

[root@localhost java]# source /etc/profile

4. Verify JDK Validity

[root@localhost java]# java -versionjava 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 2: Install JDK with yum

1. Check which jdk versions are available in the yum Library (only openjdk is found currently)

[root@localhost ~]# yum search java|grep jdkldapjdk-javadoc.x86_64 : Javadoc for ldapjdkjava-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 for installation.

// Select 1.7 for installation [root @ localhost ~] # Yum install java-1.7.0-openjdk
// After the installation is complete, the default installation directory is in:/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.75.x86_64

3. Set Environment Variables

[root@localhost ~]# 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

Make the modification take effect

[root@localhost java]# source /etc/profile

4. Verification (same method)

Method 3: Install JDK with rpm

1. Download the rpm Installation File

[root@localhost ~]$ curl -O http://download.oracle.com/otn-pub/java/jdk/7u79-b15/jdk-7u79-linux-x64.rpm

2. Run the rpm command to install

[root@localhost  ~]# rpm -ivh jdk-7u79-linux-x64.rpm

3. Set Environment Variables

[root@localhost java]# vi /etc/profile

Add the following content to the opened 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

Make the modification take effect

[root@localhost java]# source /etc/profile

4. Verification (same method)

Note: similar to yum installation, java commands can be run without setting environment variables. By default, the jdk is installed in/usr/java/jdk1.7.0 _ 79 by rpm, and then linked to/usr/bin through a layer-3 link. The specific link is as follows:

[root@localhost ~]# cd /bin[root@localhost bin]# ll|grep javalrwxrwxrwx. 1 root root     25 Mar 28 11:24 jar ->/usr/java/default/bin/jarlrwxrwxrwx. 1 root root     26 Mar 28 11:24 java -> /usr/java/default/bin/javalrwxrwxrwx. 1 root root     27 Mar 28 11:24 javac ->/usr/java/default/bin/javaclrwxrwxrwx. 1 root root     29 Mar 28 11:24 javadoc ->/usr/java/default/bin/javadoclrwxrwxrwx. 1 root root     28 Mar 28 11:24 javaws ->/usr/java/default/bin/javawslrwxrwxrwx. 1 root root     30 Mar 28 11:24 jcontrol ->/usr/java/default/bin/jcontrol[root@localhost bin]# cd /usr/java/[root@localhost java]# lltotal 4lrwxrwxrwx. 1 root root   16 Mar 28 11:24 default-> /usr/java/latestdrwxr-xr-x. 8 root root 4096 Mar 28 11:24 jdk1.7.0_79lrwxrwxrwx. 1 root root   21 Mar 28 11:24 latest -> /usr/java/jdk1.7.0_79

Method 4: Install JDK with apt-get on Ubuntu

1. Check which jdk versions are available in the apt library.

root@Itble:~# apt-cache search java|grep jdkdefault-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 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) 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 for uWSGI (OpenJDK 6)uwsgi-plugin-jwsgi-openjdk-6 - JWSGI plugin for uWSGI (OpenJDK 6)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 for installation.

root@Itble:~# apt-get install openjdk-7-jdk

3. Set Environment Variables

root@Itble:~# vi /etc/profile

Add the following content to the opened 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_HOME JRE_HOME CLASS_PATH PATH

Make the modification take effect

root@Itble:~# source /etc/profile

4. Verification (same method)