Install JAVA in CentOS 7 and in centos 7

Install JAVA in CentOS 7 and in centos 7

Step 1: Check whether the built-in JDK of Linux is 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

If yes

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

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

Step 2: Install SUN's JDK

1. Download the compressed package

2. Create an application directory (put all the software you need in this directory to facilitate the same management) for example: usersoft

Mkdir/

3. Copy the downloaded file to the/usersoft directory.

4. Enter the following command for environment variable configuration to enter the configuration file.

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

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

5. Make the environment variable 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

End!