Does docker need to install jdk?

The docker service itself does not need to install jdk. If the java application container is used, jdk needs to be installed in the container; the docker container does not have jdk by default. If you need to run the java program, install jdk in the host machine and install it in the container. jdk, the full name of jdk is "Java Development Kit", which refers to the software development tool kit of Java language. It is mainly used for the development of java applications on mobile devices and embedded devices.

The operating environment of this tutorial: linux7.3 system, docker version 19.03, Dell G3 computer.

Docker needs to install jdk

The docker service itself does not require it.

jdk is required for java applications, and docker is written in go. If your java application container is behind, you need to install jdk in the container.

Docker containers do not have JDK by default. If you need to run a Java program, you must either install JDK in the host machine or install JDK in the container. The following is how to install JDK in the container

What is jdk

jdk (full name is Java Development Kit) is a product of SunMicrosystems for Java developers. It is a software development tool kit for the Java language, mainly used for mobile devices, embedded java application on the device.

JDK is the core of the entire JAVA, including Java Runtime Envirnment, a bunch of Java tools (javac/java/jdb, etc.) and Java basic class libraries (i.e. Java API including rt.jar ).

The most mainstream JDK is the JDK released by Sun. In addition to Sun, there are many companies and organizations that have developed their own JDK. IBM has developed its own JDK, and domestic Taobao has also developed its own JDK. Each organization develops its own JDK in order to improve certain aspects to meet its own needs.

JDK is a development environment for building applications, applets, and components published on the Java platform. It does not provide specific development software. What it provides is the class library and Java language specification that must be used no matter what kind of development software you use to write Java programs.

Docker needs to install jdk separately?

The docker container does not have JDK by default. If you need to run a Java program, you must either install JDK in the host machine or install JDK in the container. Here's how to install JDK in a container.

1. Download the gz file of the required jdk version in the host system

         http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

2. Copy the gz file to the root user directory in the container

docker cp <path to jdk gz file>/jdk-8u121-linux-x64.tar.gz <容器名称或者ID>:/root

3. Enter the container

docker exec -it <容器名称或者ID> bash

4. Unzip the gz file in the container

cd ~
tar -zxvf jdk-8u121-linux-x64.tar.gz
chown root:root ~/jdk1.8.0_121 -R

5. Create the JAVA_HOME directory of the container system

mkdir /usr/lib/jvm

6. Move the jdk directory to the JAVA_HOME directory

mv ~/jdk1.8.0_121 /usr/lib/jvm

7. Install vim

yum update
yum -y install vim*

8. Set environment variables

vim ~/.bashrc
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_121 ## 这里要注意目录要换成自己解压的jdk 目录
export JRE_HOME=${JAVA_HOME}/jre
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

9. Make environment variables take effect immediately

source ~/.bashrc

10. Verify JDK version

java -version

Recommended learning: "docker video tutorial"

The above is the detailed content of Does docker need to install jdk?. For more information, please follow other related articles on the PHP Chinese website!