一、下載jdk

二、用xftp上傳到Linux系統

     你可以在root目錄下建立一個資料夾來存放該安裝包。

 [[email protected] ~]# mkdir java_jdk

然後用xftp將安裝包上傳到該資料夾

三、在/usr/local下建立一個java目錄，用於將jdk安裝包解壓在裡面。

先轉到/usr/local目錄下，然後建立資料夾

[[email protected] java_jdk]# cd /usr/local
[[email protected] local]# mkdir java

轉到/root/java_jdk目錄下去解壓剛才上傳的安裝包

[[email protected] java]# cd /root/java_jdk
[[email protected] java_jdk]# 

將安裝包解壓到安裝目錄/usr/local/java/目錄下

[[email protected] java_jdk]# tar -zxvf jdk-8u181-linux-x64.tar.gz -C /usr/local/java/

解壓完畢之後在/etc/profile檔案末尾新增下面這段程式碼

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
 

首選用vim開啟檔案/etc/profile

[[email protected] java]# vim /etc/profile

按鍵盤i鍵可以進入輸入模式，將上面程式碼段複製到末端。按ESC鍵，退出輸入模式，按Shift鍵+ “ ：”號鍵，輸入wq按回車鍵，儲存修改的檔案。如果不想儲存，則輸入q!按回車鍵退出不儲存。

使/etc/profile生效

[[email protected] java]# source /etc/profile

 檢測安裝是否成功

[[email protected] java]# java -version
java version "1.8.0_181"
Java(TM) SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)
[
 
[email protected] java]# 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

到此就安裝成功了！