How to run simple java app on amazon ec2?

Question

I have access to amazon cloud service ec2, linux instance. I created vi first.java file with this content:

class first {
    public static void main(String[] args) {
        System.out.println("abc");
    }
}

I want to compile the file using:

[root@ip-21-24-273-243 ec2-user]# javac first.java 
bash: javac: command not found

Command not found? I do:

[root@ip-21-24-273-243 ec2-user]# java -version
java version "1.6.0_24"
OpenJDK Runtime Environment (IcedTea6 1.11.9) (amazon-57.1.11.9.52.amzn1-x86_64)
OpenJDK 64-Bit Server VM (build 20.0-b12, mixed mode)

So java is installed. How can I run a simple app?

[root@ip-21-24-273-243 ec2-user]# yum install java
Loaded plugins: priorities, security, update-motd, upgrade-helper
amzn-main                                                                                                                      | 2.1 kB     00:00     
amzn-updates                                                                                                                   | 2.3 kB     00:00     
Setting up Install Process
Package 1:java-1.6.0-openjdk-1.6.0.0-57.1.11.9.52.amzn1.x86_64 already installed and latest version
Nothing to do

Solution 1

You need to install java-1.6.0-openjdk-devel:

yum install java-devel

Solution 2

As already mentioned, to compile a Java program you need JDK. Here you may find some useful information on how to install JDK on a Fedora AMI: Compiling and running Java app

However, you should notice that you don't need to compile on your ec2 instance. You can compile your Java program on your home desktop/laptop computer and transfer compiled .class (packed in a .jar) files to the instance, and run them there - the already installed JRE should be enough to run the program. That is a preferable approach, cause you can comfortably use Eclipse for development. Develop, test on your local machine, deploy on ec2.

Solution 3

There's a few steps to do:

1. Make sure you have a Java compiler installed. You can find this out by entering $javac into your console and seeing what comes up. If it's not installed, follow the previously mentioned instructions to $yum install java-devel
2. Create your script (first.java)
3. Compile it using $javac first.java
4. You will now have first.java and first.class... execute it by executing $java first

Comments

[piokuc]

right, sorry, yum is used in Fedora, Ubuntu has apt-get. Anyway, I recommend setting up development environment on your personal computer.

[piokuc]

Development on your local machine is just so much more convenient, with Eclipse and fast access to files. In theory I think you could run Eclipse remotely, but it's never going to work as fast as on your local computer.

[piokuc]

I guess you are on AWS free tier. Copying few megabytes with scp should be free.