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 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

Make the modification take effect:

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

4. Verify JDK Validity

[Root @ localhost 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 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 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 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 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

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 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

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 java
Lrwxrwxrwx. 1 root 25 Mar 28 11: 24 jar->/usr/java/default/bin/jar
Lrwxrwxrwx. 1 root 26 Mar 28 :24 java->/usr/java/default/bin/java
Lrwxrwxrwx. 1 root 27 Mar 28 :24 javac->/usr/java/default/bin/javac
Lrwxrwxrwx. 1 root 29 Mar 28 :24 javadoc->/usr/java/default/bin/javadoc
Lrwxrwxrwx. 1 root 28 Mar 28 11: 24 javaws->/usr/java/default/bin/javaws
Lrwxrwxrwx. 1 root 30 Mar 28 :24 jcontrol->/usr/java/default/bin/jcontrol
[Root @ localhost bin] # cd/usr/java/
[Root @ localhost java] # ll
Total 4
Lrwxrwxrwx. 1 root 16 Mar 28 :24 default->/usr/java/latest
Drwxr-xr-x. 8 root 4096 Mar 28 jdk1.7.0 _ 79
Lrwxrwxrwx. 1 root 21 Mar 28 :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 @ linuxidc :~ # 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)
Java runtime based on OpenJDK (debugging symbols)
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
Java runtime based on OpenJDK (debugging symbols)
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 for installation.

Root @ linuxidc :~ # Apt-get install openjdk-7-jdk

3. Set Environment Variables

Root @ linuxidc :~ # Vi/etc/profile

Add the following content to the opened 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

Make the modification take effect

Root @ linuxidc :~ # Source/etc/profile

4. Verification (same method)