Installing java in Docker image

Question

This is my very first try to create a docker image and I\'m hoping someone can help me out. My Dockerfile looks roughly like this:

FROM mybaseimage:0.1
MAINT         


        

Answer 1

I was able to install OpenJDK-8 via the steps below (taken from here). My Dockerfile inherits from phusion/baseimage-docker, which is based on Ubuntu 16.04 LTS.

# Install OpenJDK-8
RUN apt-get update && \
    apt-get install -y openjdk-8-jdk && \
    apt-get install -y ant && \
    apt-get clean;

# Fix certificate issues
RUN apt-get update && \
    apt-get install ca-certificates-java && \
    apt-get clean && \
    update-ca-certificates -f;

# Setup JAVA_HOME -- useful for docker commandline
ENV JAVA_HOME /usr/lib/jvm/java-8-openjdk-amd64/
RUN export JAVA_HOME

To install OpenJDK-7 instead, you may need to prepend

add-apt-repository ppa:openjdk-r/ppa

such that the first step becomes

# Install OpenJDK-7
RUN add-apt-repository ppa:openjdk-r/ppa && \
    apt-get update && \
    apt-get install -y openjdk-7-jdk && \
    apt-get install -y ant && \
    apt-get clean;

I hope this helps.

Answer 2

I was able to install Java-11 on an image using Ubuntu 18.04. I also just needed it for only one application. (The Python wrapper around Apache Tika.)

FROM python:3.8.2-buster
COPY . /usr/src/app

# Install OpenJDK-11
RUN apt-get update && \
    apt-get install -y openjdk-11-jre-headless && \
    apt-get clean;

# Install PYTHON requirements
COPY requirements.txt ./
RUN pip install --no-cache-dir -r requirements.txt

# START WEBAPP SERVICE
CMD [ "python", "/usr/src/app/main.py" ]

Hope that helps.

Answer 3

There is already an official repo for java, which uses Open JDK.
Its very easy to use it. Have a look over this repo, which demonstrates very basic hello world program.
Dockerfile:

FROM java:7
COPY src /home/root/java/src
WORKDIR /home/root/java
RUN mkdir bin
RUN javac -d bin src/HelloWorld.java
ENTRYPOINT ["java", "-cp", "bin", "HelloWorld"]

HelloWorld.java file:

public class HelloWorld{
    public static void main(String[] args){
        System.out.println("Hello World!!!");
    }
}