CentOS 7 配置Java语言开发环境
安装JDK8
安装Java SE开发工具包8（JDK8）并构建Java环境
- 下载并安装JDK 8
- [确保Oracle下载站点上JDK的最新版本和源URL]http://www.oracle.com/technetwork/java/javase/downloads/index.html
[root@linuxprobe ~]# curl -L "http://download.oracle.com/otn-pub/java/jdk/8u121-b13/e9e7ea248e2c4826b92b3f075a80e441/jdk-8u121-linux-x64.rpm" -H "Cookie: oraclelicense=accept-securebackup-cookie" -H "Connection: keep-alive" -O
# 采用yum或者rpm方式安裝jdk（這裡一yum為例）
[root@linuxprobe ~]# yum localinstall jdk-8u121-linux-x64.rpm -y
Loaded plugins: fastestmirror
Examining jdk-8u121-linux-x64.rpm: 2000:jdk1.8.0_121-1.8.0_121-fcs.x86_64
Marking jdk-8u121-linux-x64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package jdk1.8.0_121.x86_64 2000:1.8.0_121-fcs will be installed
--> Finished Dependency Resolution
Dependencies Resolved
===============================================================================================================================================================================================================================================================================
Package Arch Version Repository Size
===============================================================================================================================================================================================================================================================================
Installing:
jdk1.8.0_121 x86_64 2000:1.8.0_121-fcs /jdk-8u121-linux-x64 263 M
Transaction Summary
===============================================================================================================================================================================================================================================================================
Install 1 Package
Total size: 263 M
Installed size: 263 M
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : 2000:jdk1.8.0_121-1.8.0_121-fcs.x86_64 1/1
Unpacking JAR files...
tools.jar...
plugin.jar...
javaws.jar...
deploy.jar...
rt.jar...
jsse.jar...
charsets.jar...
localedata.jar...
Verifying : 2000:jdk1.8.0_121-1.8.0_121-fcs.x86_64 1/1
Installed:
jdk1.8.0_121.x86_64 2000:1.8.0_121-fcs
Complete!
[root@linuxprobe ~]# java -version
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13,mixed mode)
# 設置jdk環境變量
[root@linuxprobe ~]# vi /etc/profile
# add follows to the end
export JAVA_HOME=/usr/java/default
export PATH=$PATH:$JAVA_HOME/bin
export CLASSPATH=.:$JAVA_HOME/jre/lib:$JAVA_HOME/lib:$JAVA_HOME/lib/tools.jar
[root@linuxprobe ~]# source /etc/profile
参考链接：http://www.jb51.cc/article/p-qepumgeg-wk.html（使用curl和wget下载最新版JDK）
- 如果安装了另一个版本的JDK，请更改默认值，如下所示：
# 以java-1.8.0-openjdk為例
[root@linuxprobe ~]# yum install java-1.8.0-openjdk -y
[root@linuxprobe ~]# alternatives --config java
There are 2 programs which provide 'java'.
Selection Command
-----------------------------------------------
1 /usr/java/jdk1.8.0_121/jre/bin/java
*+ 2 java-1.8.0-openjdk.x86_64 (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.121-0.b13.el7_3.x86_64/jre/bin/java)
# 选择通过yum安装的最新版的Oracle JDK
Enter to keep the current selection[+],or type selection number: 1
- 创建测试程序确保java环境正常
[root@linuxprobe ~]# vi day.java
import java.util.Calendar;
class day {
public static void main(String[] args) {
Calendar cal = Calendar.getInstance();
int year = cal.get(Calendar.YEAR);
int month = cal.get(Calendar.MONTH) + 1;
int day = cal.get(Calendar.DATE);
int hour = cal.get(Calendar.HOUR_OF_DAY);
int minute = cal.get(Calendar.MINUTE);
System.out.println(year + "/" + month + "/" + day + " " + hour + ":" + minute);
}
}
# compile
[root@linuxprobe ~]# javac day.java
[root@linuxprobe ~]# java day
2017/4/12 21:49
