升級系統中的java到1.8版本
阿新 • • 發佈：2019-05-05
dep con 指向 bin ant deploy true 添加 dpa
(1).安裝或升級java，並配置環境變量
註意：此處分為yum安裝與rpm安裝，區別在於yum安裝省事但配置麻煩，rpm安裝麻煩但配置省事。
1）yum安裝
在安裝前可以使用yum list installed | grep jdk查看已經安裝的JDK文件
[[email protected] ~]# yum list installed | grep jdk copy-jdk-configs.noarch 3.3-10.el7_5 @updates java-1.8.0-openjdk.x86_64 1:1.8.0.212.b04-0.el7_6 @updates java-1.8.0-openjdk-headless.x86_64 1:1.8.0.212.b04-0.el7_6 @updates
再使用yum list | grep java-1.8查看1.8版本的實際安裝包
[[email protected] ~]$ yum list | grep java-1.8.0 java-1.8.0-openjdk.x86_64 1:1.8.0.212.b04-0.el7_6 @updates java-1.8.0-openjdk-headless.x86_64 1:1.8.0.212.b04-0.el7_6 @updates java-1.8.0-openjdk.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-accessibility.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-accessibility.x86_64 java-1.8.0-openjdk-accessibility-debug.i686 java-1.8.0-openjdk-accessibility-debug.x86_64 java-1.8.0-openjdk-debug.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-debug.x86_64 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-demo.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-demo.x86_64 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-demo-debug.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-demo-debug.x86_64 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-devel.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-devel.x86_64 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-devel-debug.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-devel-debug.x86_64 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-headless.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-headless-debug.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-headless-debug.x86_64 java-1.8.0-openjdk-javadoc.noarch 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-javadoc-debug.noarch java-1.8.0-openjdk-javadoc-zip.noarch 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-javadoc-zip-debug.noarch java-1.8.0-openjdk-src.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-src.x86_64 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-src-debug.i686 1:1.8.0.212.b04-0.el7_6 updates java-1.8.0-openjdk-src-debug.x86_64 1:1.8.0.212.b04-0.el7_6 updates
差太多了，我這裏使用yum -y install java-1.8*安裝下。
在使用yum安裝時是沒有辦法指定文件存放在哪裏的，所以jdk文件也不清楚在哪裏，環境變量配置上就有一定的麻煩，這一點就沒有rpm好。
我們使用which java看看java腳本最終指向何處
[[email protected] ~]$ which java /usr/bin/java [[email protected] ~]$ ll /usr/bin/java lrwxrwxrwx. 1 root root 22 5月 5 16:17 /usr/bin/java -> /etc/alternatives/java [[email protected] ~]$ ll /etc/alternatives/java lrwxrwxrwx. 1 root root 73 5月 5 16:17 /etc/alternatives/java -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/jre/bin/java [[email protected] ~]$ ll /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/jre/bin/java -rwxr-xr-x. 1 root root 7376 4月 18 01:18 /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/jre/bin/java
這裏和Windows就很類似了，我們看看有沒有必要的文件
[[email protected] ~]# ls /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64 bin demo include jre lib sample src.zip tapset [[email protected] ~]# ls /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/lib amd64 dt.jar jconsole.jar orb.idl tools.jar ct.sym ir.idl jexec sa-jdi.jar [[email protected] ~]# ls /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64/bin appletviewer java jconsole jps native2ascii schemagen xjc clhsdb javac jdb jrunscript orbd serialver extcheck javadoc jdeps jsadebugd pack200 servertool hsdb javah jhat jstack policytool tnameserv idlj javap jinfo jstat rmic unpack200 jar java-rmi.cgi jjs jstatd rmid wsgen jarsigner jcmd jmap keytool rmiregistry wsimport
沒有問題，接下來就可以像Windows一樣開始配置環境變量。註意有四個配置文件加載順序是/etc/profile>>/etc/bashrc>>~/.bashrc>>~/.bash_profile，請根據情況進行文件修改。詳見：
Shell變量的(4).添加環境變量
此處以/etc/profile配置文件為例，在文件末尾添加如下行：
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64
export PATH=${JAVA_HOME}/bin:$PATH
export CLASSPATH=.:${JAVA_HOME}/lib/dt.jar:${JAVA_HOME}/lib/tools.jar
接著刷新下配置文件
[[email protected] ~]# source /etc/profile
最後測試一下
[[email protected] ~]# java -version openjdk version "1.8.0_212" OpenJDK Runtime Environment (build 1.8.0_212-b04) OpenJDK 64-Bit Server VM (build 25.212-b04, mixed mode) [[email protected] ~]# echo $JAVA_HOME /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.212.b04-0.el7_6.x86_64
2）rpm安裝
首先需要下載一份rpm安裝包並上傳至CentOS7系統，使用rpm -ivh jdk-8u212-linux-x64.rpm安裝或升級java到1.8版本。
[[email protected] ~]# rpm -ivh jdk-8u212-linux-x64.rpm 警告：jdk-8u212-linux-x64.rpm: 頭V3 RSA/SHA256 Signature, 密鑰 ID ec551f03: NOKEY 準備中... ################################# [100%] 正在升級/安裝... 1:jdk1.8-2000:1.8.0_212-fcs ################################# [100%] Unpacking JAR files... tools.jar... plugin.jar... javaws.jar... deploy.jar... rt.jar... jsse.jar... charsets.jar... localedata.jar...
接著可以使用rpm -pql /root/jdk-8u212-linux-x64.rpm看到安裝包安裝的目錄（會列出所有，請及時停止）。當然也可以使用rpm -ivh --prefix=<dir> jdk-8u212-linux-x64.rpm安裝到指定目錄下。
看一下安裝目錄結構以便配置環境變量
[[email protected] ~]# ls /usr/java/ default jdk1.8.0_212-amd64 latest [[email protected] ~]# ls /usr/java/jdk1.8.0_212-amd64/ bin lib src.zip COPYRIGHT LICENSE THIRDPARTYLICENSEREADME-JAVAFX.txt include man THIRDPARTYLICENSEREADME.txt javafx-src.zip README.html jre release
修改/etc/profile文件，在末尾添加如下三行
export JAVA_HOME=/usr/java/jdk1.8.0_212-amd64
export PATH=${JAVA_HOME}/bin:$PATH
export CLASSPATH=.:${JAVA_HOME}/lib/dt.jzr:${JAVA_HOME}/lib/tools.jar
然後刷新配置文件
[[email protected] ~]# source /etc/profile
最後測試一下
[[email protected] ~]# echo $JAVA_HOME /usr/java/jdk1.8.0_212-amd64 您在 /var/spool/mail/root 中有新郵件 [[email protected] ~]# java -version java version "1.8.0_212" Java(TM) SE Runtime Environment (build 1.8.0_212-b10) Java HotSpot(TM) 64-Bit Server VM (build 25.212-b10, mixed mode)
升級系統中的java到1.8版本