Linux yum安装java环境

1.jdk 1.8

#系统版本

[root@localhost ~]# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core) 

#安装之前先查看一下有无系统自带jdk

rpm -qa |grep java

rpm -qa |grep jdk

rpm -qa |grep gcj

#如果有，卸载

rpm -qa | grep java | xargs rpm -e --nodeps

#yum安装1.8.0版本openjdk

[root@localhost ~]# yum install java-1.8.0-openjdk* -y

#查看版本

[root@localhost ~]# java -version
openjdk version "1.8.0_161"
OpenJDK Runtime Environment (build 1.8.0_161-b14)
OpenJDK 64-Bit Server VM (build 25.161-b14, mixed mode)

#默认jre jdk 安装路径是/usr/lib/jvm 下面

#配置jdk环境变量

vim /etc/profile
#set java environment
export JAVA_HOME=/usr/lib/jvm/java

export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/jre/lib/rt.jar

export PATH=$PATH:$JAVA_HOME/bin

#退出编辑并保存

:wq!

#使配置生效

source /etc/profile

#查看变量

[root@localhost ~]#  echo $JAVA_HOME
/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64

[root@localhost ~]# echo $CLASSPATH
.:/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64/lib/dt.jar:/usr/lib/jvm/jre-1.8.0-openjdk-1.8.0.161-0.b14.el7_4.x86_64/lib/tools.jar

2.tomcat 8

#进入指定路径

cd /root
wget http://mirrors.hust.edu.cn/apache/tomcat/tomcat-8/v8.5.34/bin/apache-tomcat-8.5.34.tar.gz

#解压压缩包

tar -zxvf apache-tomcat-8.5.34.tar.gz

#更改名称

mv apache-tomcat-8.5.34 tomcat-8

#启动tomcat

cd /root/tomcat-8/bin/

./startup.sh