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JAVB Base64URL编码/解码示例 发布于:2023-03-23 18:11 今天吃什么呢? 发布于:2023-03-22 17:37 //快速排序的代码演示 发布于:2023-03-18 21:24 按字典排序的组合 发布于:2023-03-17 10:06 01背包暴力法,基本不可能AC,填空使用 发布于:2023-03-17 00:32 迷宫问题AC 发布于:2023-03-17 00:08 JAVA 组合+ 发布于:2023-03-16 14:51 c测试程序保存 发布于:2023-03-16 11:15 JAVA 组合模板 发布于:2023-03-16 10:42 JAVA 小组分类 发布于:2023-03-16 10:34 JAVA 搭积木 发布于:2023-03-16 09:58 JAVA 牌型组合 组合+递归 发布于:2023-03-15 18:51 java first 发布于:2023-03-15 16:36 平行四边形 发布于:2023-03-16 18:29 学习枚举类 发布于:2023-03-14 15:16 vv平台留存 getBetweenDayList 发布于:2023-03-14 11:09 热点已经退回 发布于:2023-03-13 10:09 dfs模板 发布于:2023-03-13 10:24 TreeMap与HashMap 发布于:2023-03-10 14:51 学习TreeSet 发布于:2023-03-09 15:33 对象序列化与反序列化 发布于:2023-03-09 11:01 除法运算 除余运算 发布于:2023-03-08 19:22 生成验证码程序 发布于:2023-03-07 20:42 机票代码测试 发布于:2023-03-07 20:08 JAVA C10,4 发布于:2023-03-06 23:01 JAVA BFS模版(岛屿数量) 发布于:2023-03-06 22:49 JAVA 全排列+特殊预处理 蓝桥杯(李白斗酒) 发布于:2023-03-06 22:19 学习io文件操作 发布于:2023-03-06 18:52 dfs模版 发布于:2023-03-05 23:41 Hashmap的简单使用 发布于:2023-03-05 20:15 希尔排序的演示 发布于:2023-03-06 16:37 Java Hashmap 发布于:2023-03-06 19:59 JAVA 字符串分割 发布于:2023-03-03 21:19 学习链表的底层 发布于:2023-03-03 15:59 插入排序的代码 发布于:2023-03-05 10:47 java 标准版 KMP 发布于:2023-03-03 10:42 JAVA vectoe 数据结构 发布于:2023-03-02 22:47 Java 枚举类型 发布于:2023-03-02 22:32 堆的各种基础API 发布于:2023-03-02 22:19 学习arrayList的底层 发布于:2023-03-02 16:44 获取证书至服务器 发布于:2023-03-02 14:26 学习循环语句优化 发布于:2023-03-02 10:33 JAVA全排列 发布于:2023-03-07 17:33 今有 100 根绳子,当然会有 200 个绳头。 // 如果任意取绳头两两配对,把所有绳头都打结连接起来。最后会形成若干个绳圈(不考虑是否套在一起)。 // 我们的问题是:请计算最后将形成多少个绳圈的概率最大? 发布于:2023-03-01 21:46 给别人展示的测试 发布于:2023-03-01 08:56 Integer 型 发布于:2023-02-28 22:19 猜灯谜,String末尾用length()-1来表示 发布于:2023-02-28 19:49 倒挂的招牌 发布于:2023-02-27 21:32 铣削切削参数优化 发布于:2023-02-27 21:57 选择排序的代码 发布于:2023-02-28 10:28 [更多]
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How to Install Oracle JDK 8 On Debian



![java8-debian][] java8-debian

In this tutorial, we will show you how to install Oracle JDK 8 On Debian, manually.

Environment :

  1. Debian 7
  2. OpenJDK 1.7 is installed. (Switch to Oracle JDK 8 later)

At the time of writing, OpenJDK 1.8 is not included in the default apt-get repository yet. I just don’t like the default apt repository schedule, it constantly comes with older or outdated released.

Note
This guide is tested in other Debian derivatives like Ubuntu 14 and Mint 1.7.2.

1. Quick Check

1.1 A quick Java version check :

$ java -version
java version "1.7.0_75"
OpenJDK Runtime Environment (IcedTea 2.5.4) (7u75-2.5.4-1~deb7u1)
OpenJDK 64-Bit Server VM (build 24.75-b04, mixed mode)

$ javac -version
javac 1.7.0_75

An existing OpenJDK 1.7 is installed, no problem, we will show you how to switch it to JDK 8.

1.2 A quick search via apt-cache, there is no openjdk-8… yet.

$ apt-cache search openjdk

...
openjdk-7-jre - OpenJDK Java runtime, using Hotspot JIT
openjdk-7-jre-headless - OpenJDK Java runtime, using Hotspot JIT (headless)
openjdk-6-jre - OpenJDK Java runtime, using Hotspot JIT
openjdk-6-jre-headless - OpenJDK Java runtime, using Hotspot JIT (headless)
...

2. Get Oracle JDK 8

1.1 Visit Oracle JDK download page

1.2 Find a Linux x64 version, in this example, we will get the jdk-8u66-linux-x64.tar.gz via wget command.

$ pwd
/home/mkyong

$ wget --header "Cookie: oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u66-b17/jdk-8u66-linux-x64.tar.gz

If you don’t want to use wget (why?), just download the file and upload to your server manually.

3. Extracts to /opt/jdk/

3.1 Extracts it to path /opt/jdk/jdk1.8.0_66

$ pwd
/home/mkyong

$ sudo mkdir /opt/jdk/
$ sudo mv ~/jdk-8u66-linux-x64.tar.gz /opt/jdk/
$ sudo cd /opt/jdk/

$ pwd
/opt/jdk/

$ sudo tar -zxf jdk-8u66-linux-x64.tar.gz 
$ ls -ls
total 177056
     4 drwxr-xr-x 3 root root      4096 Oct 27 13:05 .
     4 drwxr-xr-x 3 root root      4096 Oct 27 13:03 ..
     4 drwxr-xr-x 8 uucp  143      4096 Oct  7 00:40 jdk1.8.0_66
177044 -rw-r--r-- 1 root root 181287376 Oct  8 15:56 jdk-8u66-linux-x64.tar.gz

Note
Alternatively, try this one line extraction command.

$ sudo tar x -C /opt/jdk -f jdk-8u66-linux-x64.tar.gz

4. Install JDK

4.1 Make /opt/jdk/jdk1.8.0_66 as a new JDK alternatives for both /usr/bin/java and /usr/bin/javac

$ sudo update-alternatives --install /usr/bin/java java /opt/jdk/jdk1.8.0_66/bin/java 100
$ sudo update-alternatives --install /usr/bin/javac javac /opt/jdk/jdk1.8.0_66/bin/javac 100

4.2 Update the default JDK, for both java and javac

$ update-alternatives --config java
There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                            Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1051      auto mode
* 1            /opt/jdk/jdk1.8.0_66/bin/java                    100       manual mode
  2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1051      manual mode

Press enter to keep the current choice[*], or type selection number: 1
update-alternatives: using /opt/jdk/jdk1.8.0_66/bin/java to provide /usr/bin/java (java) in manual mode
$ update-alternatives --config javac
There are 2 choices for the alternative javac (providing /usr/bin/javac).

  Selection    Path                                         Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-7-openjdk-amd64/bin/javac   1051      auto mode
* 1            /opt/jdk/jdk1.8.0_66/bin/javac                100       manual mode
  2            /usr/lib/jvm/java-7-openjdk-amd64/bin/javac   1051      manual mode

Press enter to keep the current choice[*], or type selection number: 1
update-alternatives: using /opt/jdk/jdk1.8.0_66/bin/javac to provide /usr/bin/javac (javac) in manual mode

5. Verification

Check Java version again.

$ java -version
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)
root@hydra:/opt/jdk# 

$ javac -version
javac 1.8.0_66

Done. Enjoy your Lambda!

6. Extras… How to Upgrade?

Let say new jdk1.8.0_99 is released, and we want to upgrade it.

6.1 Download the JDK tar files and extracts it to /opt/jdk/jdk1.8.0_99

6.2 Self-explanatory.

# 6.2.1 Remove the existing alternatives - jdk1.8.0_66
$ sudo update-alternatives --remove java /opt/jdk/jdk1.8.0_66/bin/java
$ sudo update-alternatives --remove javac /opt/jdk/jdk1.8.0_66/bin/javac

# 6.2.2 Install new JDK alternatives - jdk1.8.0_99
$ sudo update-alternatives --install /usr/bin/java java /opt/jdk/jdk1.8.0_99/bin/java 100
$ sudo update-alternatives --install /usr/bin/javac javac /opt/jdk/jdk1.8.0_99/bin/javac 100

# 6.2.3 Update default JDK again, select /opt/jdk/jdk1.8.0_99
$ update-alternatives --config java 
$ update-alternatives --config javac

# 6.2.4 Remove the old JDK folders
$ sudo rm -rf /opt/jdk/jdk1.8.0_66/

How about upgrade to the upcoming Oracle JDK 9? you know what to do :)

References

  1. Using the Debian alternatives system
  2. How To Manually Install Oracle Java on a Debian or Ubuntu VPS
  3. Debian : Change default Java version
  4. Oracle JDK download page

[java8-debian]:

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