1.升级JDK
a.查看当前JDK版本
[root@vi tomcat]# java -version java version "1.7.0_91" OpenJDK Runtime Environment (rhel-2.6.2.2.el6_7-x86_64 u91-b00) OpenJDK 64-Bit Server VM (build 24.91-b01, mixed mode)
b.卸载当前JDK
yum remove java
c.查找JDK包
yum search java
java-1.5.0-gcj.x86_64 : JPackage runtime compatibility layer for GCJ java-1.5.0-gcj-devel.x86_64 : JPackage development compatibility layer for GCJ java-1.5.0-gcj-javadoc.x86_64 : API documentation for libgcj java-1.5.0-gcj-src.x86_64 : Source files for libgcj 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-debug.x86_64 : OpenJDK Runtime Environment with full debug on java-1.8.0-openjdk-demo.x86_64 : OpenJDK Demos java-1.8.0-openjdk-demo-debug.x86_64 : OpenJDK Demos with full debug on java-1.8.0-openjdk-devel.x86_64 : OpenJDK Development Environment java-1.8.0-openjdk-devel-debug.x86_64 : OpenJDK Development Environment with full debug on java-1.8.0-openjdk-headless.x86_64 : OpenJDK Runtime Environment java-1.8.0-openjdk-headless-debug.x86_64 : OpenJDK Runtime Environment with full debug on java-1.8.0-openjdk-javadoc.noarch : OpenJDK API Documentation
d.选择JDK8（java-1.8.0-openjdk.x86_64）进行安装
yum install java-1.8.0-openjdk.x86_64
e.查看新安装的java版本
[root@vi tomcat]# java -version openjdk version "1.8.0_65" OpenJDK Runtime Environment (build 1.8.0_65-b17) OpenJDK 64-Bit Server VM (build 25.65-b01, mixed mode)
2.下载和安装tomcat8
a.下载
[root@vi myfile]# wget http://mirrors.cnnic.cn/apache/tomcat/tomcat-8/v8.0.30/bin/apache-tomcat-8.0.30.tar.gz
b.解压和安装
[root@vi myfile]# tar -zxvf apache-tomcat-8.0.30.tar.gz
[root@vi myfile]# mv apache-tomcat-8.0.30 /usr/local/tomcat/
c.修改配置
vim /usr/local/tomcat/bin/catalina.sh
添加：CATALINA_HOME=/usr/local/tomcat
d.启动tomcat
[root@vi myfile]# /usr/local/tomcat/bin/startup.sh Using CATALINA_BASE: /usr/local/tomcat Using CATALINA_HOME: /usr/local/tomcat Using CATALINA_TMPDIR: /usr/local/tomcat/temp Using JRE_HOME: /usr Using CLASSPATH: /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar Tomcat started.
f.测试tomcat
原文：http://www.cnblogs.com/vijayfly/p/5104114.html