Install JDK on CentOS 7

用yum安装JDK

1.查看yum库中都有哪些jdk版本(暂时只发现了openjdk)
[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 the version to install
//Select the 1.7 version to install
[root@localhost ~]# yum install java-1.7.0-openjdk
//After installation, the default installation The 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 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=JAVAHOME/jreCLASSPATH=.:JAVA_HOME/lib/dt.jar:JAVAHOME /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
java -version