Shulou(Shulou.com)06/02 Report--

CentOS 7 may have installed OpenJDK JRE by default after successful installation, but usually Java development needs to use a complete JDK, so in order to avoid unnecessary trouble in the future, uninstall OpenJDK JRE here, and reinstall Oracle JDK8

1. installation instructions

System environment: CentOS 7

Installation mode: rpm

Installation package: jdk-8u131-linux-x64.rpm

2. Check system original installation version [hadoop@centos7-1 ~]$ java -versionOpenJDK Version "1.8.0_131"OpenJDK Runtime Environment (build 1.8.0_131-b12)OpenJDK 64-Bit Server VM (build 25.131-b12, mixed mode)[hadoop@centos7-1 ~]$ rpm -qa| grep javalibvirt-java-devel-0.4.9-4.el7.noarchtzdata-java-2017b-1.el7.noarchjava-1.8.0-openjdk-headless-1.8.0.131-3.b12.el7_3.x86_64java-1.7.0-openjdk-1.7.0.141-2.6.10.1.el7_3.x86_64libvirt-java-0.4.9-4.el7.noarchjavapackages-tools-3.4.1-11.el7.noarchjava-1.7.0-openjdk-headless-1.7.0.141-2.6.10.1.el7_3.x86_64java-1.8.0-openjdk-1.8.0.131-3.b12.el7_3.x86_64python-javapackages-3.4.1-11.el7.noarch[hadoop@centos7-1 ~]$3. Uninstall the installed openjdklibvirt-java-devel-0.4.9-4.el7. nolibarchvirt-java-0.4.9- 4.el7.noarchtzdata-java-2017b-1.el7.noarchjava-1.8.0-openjdk-headless-1.8.0.131-3.b12.el7_3.x86_64java-1.7.0-openjdk-1.7.0.141-2.6.10.1.el7_3.x86_64java-1.7.0-openjdk-headless-1.7.0.141-2.6.10.1.el7_3.x86_64java-1.8.0-openjdk-1.8.0.131-3.b12.el7_3.x86_64

Run the following command as root

[root@centos7-1 hadoop]# rpm -e --nodeps libvirt-java-devel-0.4.9-4.el7.noarch[root@centos7-1 hadoop]# rpm -e --nodeps libvirt-java-0.4.9-4.el7.noarch[root@centos7-1 hadoop]# rpm -e --nodeps tzdata-java-2017b-1.el7.noarch[root@centos7-1 hadoop]# rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.141- 2.6.10.1.el7_3.x86_64[root@centos7-1 hadoop]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.141-2.6.10.1.el7_3.x86_64[root@centos7-1 hadoop]# rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.131-3.b12.el7_3.x86_64[root@centos7-1 hadoop]# rpm -e --nodeps java-1.8.0-openjdk-1.8.0.131-3.b12.el7_3.x86_644. install jdk[root@centos7-1 local]#ll/usr/local/jdk-8u131-linux-x64.rpm-rw-r--. 1 root root 169983496 Jun 12 23:17 /usr/local/jdk-8u131-linux-x64.rpm[root@centos7-1 local]# rpm -ivh jdk-8u131-linux-x64.rpm Preparing.. ################################# [100%] Updating / installing... 1:jdk1.8.0_131-2000:1.8.0_131-fcs ################################# [100%] Unpacking JAR files... tools.jar... plugin.jar... javaws.jar... deploy.jar... rt.jar... jsse.jar... charsets.jar... localedata.jar... [root@centos7-1 local]#

The requested URL/java/was not found on this server.

[root@centos7-1 local]# ll /usr/java/total 0lrwxrwxrwx. 1 root root 16 Jun 12 23:18 default -> /usr/java/latestdrwxr-xr-x. 9 root root 268 Jun 12 23:18 jdk1.8.0_131lrwxrwxrwx. 1 root root 22 Jun 12 23:18 latest -> /usr/java/jdk1.8.0_131[root@centos7 -1 local]# 5. Verify installation [root@centos7-1 local]# ll /usr/bin/javalrwxrwx. 1 root root 22 Jun 12 23:18 /usr/bin/java -> /etc/alternatives/java[root@centos7-1 local]# ll /etc/alternatives/javalrwxrwx. 1 root 35 Jun 12 23:18 /etc/alternatives/java -> /usr/java/jdk1.8.0_131/jre/bin/java[root@centos7-1 local]# java -versionjava version "1.8.0_131"Java(TM) SE Runtime Environment (build 1.8.0_131-b11)Java HotSpot(TM) 64-Bit Server VM (build 25.131-b11, mixed mode)[root@centos7-1 local]# 6. Configure environmental variables [hadoop@centos7 - 1 ~]$ whoamihadoop[hadoop@centos7 - 1 ~]$ vi ~/.bashrc

Set JAVA_HOME and add it to PATH

JAVA_HOME=/usr/java/defaultPATH=$PATH:$JAVA_HOME/binexport JAVA_HOME PATH

Run the source command to make the changes take effect. Output JAVA_HOME, PATH to confirm whether the changes take effect.

[hadoop@centos7-1 ~]$ source ~/.bashrc[hadoop@centos7-1 ~]$ echo $JAVA_HOME/usr/java/default[hadoop@centos7-1 ~]$ echo $PATH/usr/lib64/qt-3.3/bin:/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:/home/hadoop/.local/bin:/home/hadoop/bin:/usr/java/default/bin

So far, the installation of JDK8 on CentOS 7 has been successfully completed. For more articles on installing JDK under Linux, please see the following related links.

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