linux下java环境变量配置（1.8）
yum install lrzsz(下载上传工具)
下载jdk1.8.linux.zip上传到linux服务器（我一般上传到 /opt 下）
pwd
[root@localhost opt]# pwd /opt [root@localhost opt]# ll jdk-1.8-linux-x64.tar.gz
tar zxf jdk-1.8-linux-x64.tar.gz
vim /etc/profile
#在末尾添加
export JAVA_HOME=/opt/jdk1.8.0_231 export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar export PATH=$JAVA_HOME/bin:$PATH
按 ESC 在按：wq 保存退出
执行以下这一步
source /etc/profile #这一步是刷新 一定要执行 要不不生效
在执行查询
javac 和java（要出现以下类容）
[root@localhost jdk1.8.0_231]# javac Usage: javac <options> <source files> where possible options include: -g Generate all debugging info -g:none Generate no debugging info -g:{lines,vars,source} Generate only some debugging info -nowarn Generate no warnings -verbose Output messages about what the compiler is doing -deprecation Output source locations where deprecated APIs are used -classpath <path> Specify where to find user class files and annotation processors -cp <path> Specify where to find user class files and annotation processors -sourcepath <path> Specify where to find input source files -bootclasspath <path> Override location of bootstrap class files -extdirs <dirs> Override location of installed extensions -endorseddirs <dirs> Override location of endorsed standards path -proc:{none,only} Control whether annotation processing and/or compilation is done. -processor <class1>[,<class2>,<class3>...] Names of the annotation processors to run; bypasses default discovery process -processorpath <path> Specify where to find annotation processors -parameters Generate metadata for reflection on method parameters -d <directory> Specify where to place generated class files -s <directory> Specify where to place generated source files -h <directory> Specify where to place generated native header files -implicit:{none,class} Specify whether or not to generate class files for implicitly referenced files -encoding <encoding> Specify character encoding used by source files -source <release> Provide source compatibility with specified release -target <release> Generate class files for specific VM version -profile <profile> Check that API used is available in the specified profile -version Version information -help Print a synopsis of standard options -Akey[=value] Options to pass to annotation processors -X Print a synopsis of nonstandard options -J<flag> Pass <flag> directly to the runtime system -Werror Terminate compilation if warnings occur @<filename> Read options and filenames from file
查看版本执行 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) 这就可以了 你装其他的版本也可以 就这样配就可以，（希望大家多多支持点赞！！）
