#查看jdk版本
[root@vm73 ~]# yum list installed | grep jdk
copy-jdk-configs.noarch               3.3-10.el7_5                     @base    
java-11-openjdk.x86_64                1:11.0.5.10-0.el7_7              @updates 
java-11-openjdk-headless.x86_64       1:11.0.5.10-0.el7_7              @updates

#卸载openjdk
yum remove copy-jdk-configs.noarch

http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

#创建安装目录
mkdir /usr/local/java/

#解压
tar -zxvf jdk-8u231-linux-x64.tar.gz -C /usr/local/java/

vim /etc/profile

export JAVA_HOME=/usr/local/java/jdk1.8.0_231
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JAVA_HOME/jre/lib/rt.jar
export PATH=$PATH:$JAVA_HOME/bin

#立即生效
source /etc/profile

#添加软链接
ln -s /usr/local/java/jdk1.8.0_231/bin/java /usr/bin/java

[root@vm73 ~]# java -version
java version "1.8.0_231"
Java(TM) SE Runtime Environment (build 1.8.0_231-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.231-b11, mixed mode)

nohup java -jar consumer-1.0-SNAPSHOT.jar > logs.info 2>&1 &