Tomcat configuration

Introduction to Tomcat

Tomcat is a core project in the Jakarta project of the Apache Software Foundation, developed jointly by Apache, Sun and some other companies and individuals.
A website written by a java program uses tomcat+jdk to run
tomcat, which is a middleware. It really works. It is jdk that parses the java script.
jdk (java development kit) is the core of the entire java. It includes the java runtime environment and a bunch of java. Related tools and basic java libraries.
The most mainstream jdk is the jdk released by sun company. In addition, IBM company also released JDK. You can also use yum to install openjdk on CentOS.

download jdk

官网下载地址 http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
下载jdk8，放到/usr/local/src/目录下

decompress

tar -zxvf jdk-8u161-linux-x64.tar.gz

move

mv jdk1.8.0_161/ /usr/local/jdk1.8

Set environment variables

vim  /etc/profile //最后面增加
vim /etc/profile.d/java.sh  //或者单独写个java的环境变量
JAVA_HOME=/usr/local/jdk1.8/
JAVA_BIN=/usr/local/jdk1.8/bin
JRE_HOME=/usr/local/jdk1.8/jre
PATH=$PATH:/usr/local/jdk1.8/bin:/usr/local/jdk1.8/jre/bin
CLASSPATH=/usr/local/jdk1.8/jre/lib:/usr/local/jdk1.8/lib:/usr/local/jdk1.8/jre/lib/charsets.jar
export  JAVA_HOME  JAVA_BIN JRE_HOME  PATH  CLASSPATH
保存文件后，使其生效:
source /etc/profile.d/java.sh  或者用 . /etc/profile.d/java.sh

Verify that java is successful

java -version
//如果显示的版本不对，查查是不是有系统自带的java或者安装了其他的版本