Install JAVA in CentOS

Step 1: Check whether the built-in JDK of Linux is installed (uninstall centOS 1.4 installed). after CentOS is installed, it comes with OpenJdk. run the java-version command. the following information is displayed: javaversion & quot; 1.6.0 & quot; OpenJDKRuntimeEnvironment (build1.6.0-b09) OpenJDK64-BitS

Step 1: Check whether the built-in JDK of Linux is installed (uninstall centOS 1.4 installed)

The installed CentOS comes with OpenJdk and uses the java-version command. the following information is displayed:

Java version "1.6.0"
OpenJDK Runtime Environment (build 1.6.0-b09)
OpenJDK 64-Bit Server VM (build 1.6.0-b09, mixed mode)

It is best to uninstall openjdk first and install the jdk of sun.

Check rpm-qa | grep java first

The following information is displayed:

Java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
Java-1.6.0-openjdk-1.6.0.0-1.7.b09.el5

Uninstall:

Rpm-e -- nodeps java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
Rpm-e -- nodeps java-1.6.0-openjdk-1.6.0.0-1.7.b09.el5

There are other commands

Rpm-qa | grep gcj

Rpm-qa | grep jdk

If openjdk source cannot be found, you can uninstall it like this.

Yum-y remove java java-1.4.2-gcj-compat-1.4.2.0-40jpp.115
Yum-y remove java java-1.6.0-openjdk-1.6.0.0-1.7.b09.el5

<1> # rpm-qa | grep jdk plugin to view jdk information or directly execute
Or
# Rpm-q jdk
Or
# Java-version
<2> # rpm-qa | grep gcj release confirm the gcj version number
<3> # yum-y remove java-1.4.2-gcj-compat uninstall gcj

 

Step 2: install SUN's JDK.

Official website: http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html

 

Create a java directory under/usr to install the java program in this directory. enter the following command:

Linux code

1. Mkdir/usr/java

 

Copy the downloaded file to the/usr/java directory and enter the following command:

[Plain]View plaincopy

1. [Root @ localhost java] # mv/home/ivan/Downloads/jdk-7u60-linux-x64.rpm/usr/java
2. [Root @ localhost java] # ls
3. Jdk-7u60-linux-x64.rpm
4. [Root @ localhost java] # rpm-ivh jdk-7u60-linux-x64.rpm
5. Preparing... ######################################## ### [100%]
6. 1: jdk ####################################### #### [100%]
7. Unpacking JAR files...
8. Rt. jar...
9. Jsse. jar...
10. Charsets. jar...
11. Tools. jar...
12. Localedata. jar...
13. Jfxrt. jar...
14. [Root @ localhost java] # ls
15. Default jdk1.7.0 _ 60 jdk-7u60-linux-x64.rpm latest

Enter the following command to enter the configuration file.

[Root @ localhost java] # vi/etc/profile
Add

Export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL
Export JAVA_HOME =/usr/java/jdk1.7.0 _ 60
Export PATH = $ JAVA_HOME/bin: $ PATH
Export CLASSPATH =.: $ JAVA_HOME/lib/dt. jar: $ JAVA_HOME/lib/tools. jar

 

Make environment variables take effect.

Execute the configuration file to make it take effect immediately. enter the following command:

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

View the version currently installed in java
[Root @ localhost java] # java-version
Java version "1.7.0 _ 60"
Java (TM) SE Runtime Environment (build 1.7.0 _ 60-b19)
Java HotSpot (TM) 64-Bit Server VM (build 24.60-b09, mixed mode)

This article references http://hermosa-young.iteye.com/blog/1798026