Linux CentOS 6.9安裝 jdk-9.0.4_linux-x64
目錄
1、下載JDK
2、卸載JDK
3、安裝JDK
3、.rpm後綴格式JDK安裝方式
4、驗證安裝
1、下載JDK
根據操作系統的位數下載對應的JDK,操作系統是32位的就下32位的JDK,64位的就下64位的JDK。Linux x86是32位JDK,Linux x64是64位JDK。
Linux下的JDK安裝包現有兩種格式.rpm和.tar.gz。rpm是redhat紅帽的標準安裝包,rpm安裝時會自動配置。
本安裝示例在CentOS 6.6系統下進行,其它類型Linux系統安裝方式相同,下載的JDK版本爲jdk-9.0.4_linux-x64_bin.rpm,對.rpm和.tar.gz安裝方式分別說明,本處已下載兩種格式的文件。
jdk-9.0.4_linux-x64_bin.rpm
下載地址:http://www.oracle.com/technetwork/java/javase/downloads/jdk9-downloads-3848520.html
2、卸載JDK
查看系統是否已安裝JDK。一般的linux都默認使用了開源的openJDK。顯示JDK版本信息,已經安裝JDK,否則沒有安裝。命令行:
- java -version
[root@localhost ~]# java -version
java version "1.7.0_131"
OpenJDK Runtime Environment (rhel-2.6.9.0.el6_8-x86_64 u131-b00)
OpenJDK 64-Bit Server VM (build 24.131-b00, mixed mode)
查找名字包含java,jdk的已安裝程序。查找到了,已經安裝JDK,否則沒有安裝。命令行:
- rpm -qa | grep java
- rpm -qa | grep jdk
[root@localhost ~]# rpm -qa | grep java
tzdata-java-2016j-1.el6.noarch
java-1.7.0-openjdk-1.7.0.131-2.6.9.0.el6_8.x86_64
java-1.6.0-openjdk-1.6.0.41-1.13.13.1.el6_8.x86_64
[root@localhost ~]# rpm -qa | grep jdk
java-1.7.0-openjdk-1.7.0.131-2.6.9.0.el6_8.x86_64
java-1.6.0-openjdk-1.6.0.41-1.13.13.1.el6_8.x86_64
已安裝JDK,卸載系統上的JDK。
單個卸載程序,使用rpm -e xxx命令。命令行:
- rpm -e jdk-1.7.0_79-fcs.x86_64
[root@localhost Desktop]# rpm -e java-1.7.0-openjdk-1.7.0.131-2.6.9.0.el6_8.x86_64
批量卸載所有名字包含jdk的已安裝程序。命令行:
- rpm -qa | grep jdk | xargs rpm -e --nodeps
[root@localhost Desktop]# rpm -qa | grep jdk | xargs rpm -e --nodeps
批量卸載所有名字包含java的已安裝程序。命令行:
- rpm -qa | grep java | xargs rpm -e --nodeps
[root@localhost Desktop]# rpm -qa | grep java | xargs rpm -e --nodeps
卸載後,查看JDK版本,已無信息,卸載成功。命令行:
- java -version
[root@localhost ~]# java -version
-bash: /usr/bin/java: 沒有那個文件或目錄
3、.rpm後綴格式JDK安裝方式
安裝jdk-9.0.4_linux-x64_bin.rpm。
給安裝包添加權限。命令行:
- chmod 755 jdk-9.0.4_linux-x64_bin.rpm
[root@localhost Desktop]# chmod 755 jdk-9.0.4_linux-x64_bin.rpm
使用rpm -ivh xxx命令安裝JDK。命令行:
- rpm -ivh jdk-9.0.4_linux-x64_bin.rpm
[root@localhost Desktop]# rpm -ivh jdk-9.0.4_linux-x64_bin.rpm
Preparing... ########################################### [100%]
1:jdk ########################################### [100%]
Unpacking JAR files...
rt.jar...
jsse.jar...
charsets.jar...
tools.jar...
localedata.jar...
jfxrt.jar...
安裝.rpm格式後綴的JDK不需要配置java環境變量,會自動配置,會在/usr/bin生成java、javac等JDK的快捷方式圖標,這些圖標會鏈接指向到/usr/java/jdk-9.0.4_linux-x64中。用echo $PATH查看環境變量,可以看到/usr/bin是加入了PATH環境變量中的。命令行:
- echo $PATH
[root@localhost Desktop]# echo $PATH
/usr/local/sbin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin:/root/bin
4、驗證安裝
安裝完成後,查看JDK版本。命令行:
- java -version
測試下javac命令是否可用。命令行:
- javac
[root@localhost Desktop]# 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
-d <directory> Specify where to place generated class files
-s <directory> Specify where to place generated source 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
-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
還可以寫段代碼測試下。用VI編輯java代碼測試JDK是否能正常編譯。按Insert鍵進入編輯狀態。命令行:
- vi test.java
- class test
- {
- public static void main(String[]args)
- {
- System.out.println("Hello World!");
- }
- }
[root@localhost Desktop]# vi test.java
class test
{
public static void main(String[]args)
{
System.out.println("Hello World!");
}
}
寫好後,按Esc退出,按Shift加英文冒號shift + : 然後輸入wq,按Enter回車鍵確認。
編譯運行。命令行:
- javac test.java
- java test
[root@localhost Desktop]# javac test.java
[root@localhost Desktop]# java test
Hello World!