下面将介绍如何在Linux(CentOS 6.7)系统上，安装JDK 1.8及tomcat 8。
所需软件包：
1) jdk-8u65-linux-x64.tar.gz
下载地址：http://download.oracle.com/otn-pub/java/jdk/8u65-b17/jdk-8u65-linux-x64.tar.gz
2) apache-tomcat-8.0.28.tar.gz
下载地址：http://mirrors.hust.edu.cn/apache/tomcat/tomcat-8/v8.0.28/bin/apache-tomcat-8.0.28.tar.gz
相关步骤：
1. 进入root家目录，将这两个包复制到 /usr/local/ 目录下，分别解压
[root@localhost ~]# cp jdk-8u65-linux-x64.tar.gz apache-tomcat-8.0.28.tar.gz /usr/local/
tar zxf jdk-8u65-linux-x64.tar.gz
tar zxf apache-tomcat-8.0.28.tar.gz
2. 配置相关环境变量
[root@localhost bin]# cd /usr/local/apache-tomcat-8.0.28/bin
[root@localhost bin]# vi setclasspath.sh
在# Make sure prerequisite environment variables are set 后面加上：
export JAVA_HOME=/usr/local/jdk1.8.0_65
export JRE_HOME=/usr/local/jdk1.8.0_65/jre
3. 启动，停止tomcat
[root@localhost bin]# ./startup.sh
Using CATALINA_BASE: /usr/local/apache-tomcat-8.0.28
Using CATALINA_HOME: /usr/local/apache-tomcat-8.0.28
Using CATALINA_TMPDIR: /usr/local/apache-tomcat-8.0.28/temp
Using JRE_HOME: /usr/local/jdk1.8.0_65/jre
Using CLASSPATH: /usr/local/apache-tomcat-8.0.28/bin/bootstrap.jar:/usr/local/apache-tomcat-8.0.28/bin/tomcat-juli.jar
Tomcat started.
[root@localhost bin]# ./shutdown.sh
Using CATALINA_BASE: /usr/local/apache-tomcat-8.0.28
Using CATALINA_HOME: /usr/local/apache-tomcat-8.0.28
Using CATALINA_TMPDIR: /usr/local/apache-tomcat-8.0.28/temp
Using JRE_HOME: /usr/local/jdk1.8.0_65/jre
Using CLASSPATH: /usr/local/apache-tomcat-8.0.28/bin/bootstrap.jar:/usr/local/apache-tomcat-8.0.28/bin/tomcat-juli.jar
至此，JDK 1.8及tomcat 8安装完毕。