Centos7下安裝與解除安裝Jdk1.8
檢視已經安裝的jdk
[[email protected] jre]# rpm -qa|grep jdk
java-1.8.0-openjdk-headless-1.8.0.65-3.b17.el7.x86_64
java-1.7.0-openjdk-1.7.0.91-2.6.2.3.el7.x86_64
java-1.7.0-openjdk-headless-1.7.0.91-2.6.2.3.el7.x86_64
java-1.8.0-openjdk-1.8.0.65-3.b17.el7.x86_64
解除安裝指令
[[email protected] jre]# yum -y remove java-1.8.0-openjdk-headless-1.8.0.65-3.b17.el7.x86_64
解除安裝完成之後Java指令不被識别
[[email protected] lib]# java -version
bash: java: command not found…
安裝
去官網下載下傳jdk：http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
解壓到安裝目錄
[[email protected] software]# tar -zxvf jdk-8u101-linux-x64.tar.gz -C /usr/local/java/
安裝完畢之後在/etc/profile檔案末尾添加
[[email protected] software]# vim /etc/profile
export JAVA_HOME=/usr/local/java/jdk1.8.0_101
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH
使/etc/profile生效
[[email protected] jdk1.8.0_101]# source /etc/profile
檢測安裝是否成功
[[email protected] jdk1.8.0_101]# java -version
java version “1.8.0_101”
Java(TM) SE Runtime Environment (build 1.8.0_101-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.101-b13, mixed mode)
[[email protected] jdk1.8.0_101]# javac
Usage: javacwhere 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 Specify where to find user class files and annotation processors
-cp Specify where to find user class files and annotation processors
-sourcepath Specify where to find input source files
-bootclasspath Override location of bootstrap class files
-extdirs Override location of installed extensions
-endorseddirs Override location of endorsed standards path
-proc:{none,only} Control whether annotation processing and/or compilation is done.
-processor [,,…] Names of the annotation processors to run; bypasses default discovery process
-processorpath Specify where to find annotation processors
-parameters Generate metadata for reflection on method parameters
-d Specify where to place generated class files
-s Specify where to place generated source files
-h Specify where to place generated native header files
-implicit:{none,class} Specify whether or not to generate class files for implicitly referenced files
-encoding Specify character encoding used by source files
-source Provide source compatibility with specified release
-target Generate class files for specific VM version
-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
-JPass directly to the runtime system
-Werror Terminate compilation if warnings occur
@Read options and filenames from file