43 lines
1.6 KiB
Markdown
43 lines
1.6 KiB
Markdown
# What is Java?
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Java is a concurrent, class-based, object-oriented language specifically
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designed to have as few implementation dependencies as possible. It is intended
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to allow application developers to "write once, run anywhere", meaning that code
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that runs on one platform does not need to be recompiled to run on another.
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Java is a registered trademark of Oracle and/or its affiliates.
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> [wikipedia.org/wiki/Java_(programming_language)](http://en.wikipedia.org/wiki/Java_(programming_language))
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# How to use this image
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## Start a Java instance in your app
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The most straightforward way to use this image is to use a Java container as
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both the build and runtime environment. In your `Dockerfile`, writing something
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along the lines of the following will compile and run your project:
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FROM java:7
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COPY . /usr/src/myapp
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WORKDIR /usr/src/myapp
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RUN javac Main.java
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CMD ["java", "Main"]
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You can then run and build the Docker image:
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docker build -t my-java-app .
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docker run -it --rm --name my-running-app my-java-app
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## Compile your app inside the Docker container
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There may be occasions where it is not appropriate to run your app inside a
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container. To compile, but not run your app inside the Docker instance, you can
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write something like:
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docker run --rm -v "$(pwd)":/usr/src/myapp -w /usr/src/myapp java:7 javac Main.java
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This will add your current directory as a volume to the container, set the
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working directory to the volume, and run the command `javac Main.java` which
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will tell Java to compile the code in `Main.java` and output the Java class file
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to `Main.class`.
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