Install JDK and environment variable configuration under Linux Centos7 __linux

Step One: View and uninstall the OPENJDK from CentOS

# installed CentOS will bring openjdk, with command Java-version, will have the following information:
[root@localhost ~]# java-version
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's best to uninstall Ope first NJDK, installing the Sun's JDK. First Check Rpm-qa | grep Java
Displays the following information:
   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

also has a few other commands:
Rpm-qa | grep gcj
RPM-QA | grep jdk

If there is no ope found NJDK source, then you can also uninstall:
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

The second step: first to the official website to download JDK. http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html, I download jdk-7u45-linux-x64.tar.gz, download to the home directory.

Step Three: Unpack the source pack

# Create a new Java folder in the/usr/local directory via the terminal, command line:
sudo mkdir/usr/local/java

# then copy the download to the compressed package to the Java folder, command line: Go to the directory
where the JDK source package resides CP Jdk-7u45-linux-x64.tar.gz/usr/local/java

# then go to the Java directory, command line:
Cd/usr/local/java

# Unzip the zip package, command line:
sudo Tar xvf jdk-7u45-linux-x64.tar.gz

# Then you can delete the compression package, command line:
sudo rm jdk-7u45-linux-x64.tar.gz

Fourth Step: Set JDK environment variables

# Here is the global setting method, which is to modify the Etc/profile, which is the shared environment variable for all users
Gedit/etc/profile

# opened to add export at the end
java_home=/usr/ local/java/jdk1.7.0_79
export classpath=.: $JAVA _home/jre/lib/rt.jar: $JAVA _home/lib/dt.jar: $JAVA _home/lib/ Tools.jar
export path= $PATH: $JAVA _home/bin

# Remember, in the above add process, do not add a space on either side of the equal sign, otherwise "not valid identifier" will appear
because source/etc/ Profile does not recognize redundant to spaces, will be understood as a path part. Then save the
source/etc/profile

Step Fifth: Verify that the installation is successful

# in the terminal
java-version to

see if the successful installation
will display the following
Java version "1.7.0_45"
Java (TM) SE Runtime Environment (Build 1.7.0_45-b18)
Java HotSpot (TM) 64-bit Server VM (build 24.45-b08, Mixed mode)