1. Download jdk
2. Installation
3. Configuration
Modify the configuration system configuration environment, add vi /etc/profile at the end:
## --------------------- JDK -------------------------- ##
JAVA_HOME=/usr/java/jdk1.7.0_79
JRE_HOME=/usr/java/jdk1.7.0_79/jre
PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin
CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/lib
export JAVA_HOME JRE_HOME PATH CLASSPATH
4. Assistance
In the /opt/soft/ directory, use the rm -rf jdk1.6.0_22 command to delete jdk
Then delete the configuration in /etc/profile