How to run a java software which needs RXTX on a raspberry pi

In my last posting i wrote about migrating my aircraft noise measurement station to alpine linux. There i had some problems with getting the RXTX library for Java running on a linux, which uses musl and not GNU libc6.

Why does my java application require RXTX? As stated on the RXTX page:

RXTX is a Java library, using a native implementation (via JNI), providing serial and parallel communication for the Java Development Toolkit (JDK).

Now i wanted to move to a raspberry pi. But this runs on ARM and the RXTX is only provided for x86/x64 systems.

But there is another way: ser2net

With this proxy /dev/ttyUSB0 can be mapped to a tcp port and java can access this without using RXTX.

Alpine Linux, Oracle Java JDK and musl?! - why it does not work...

Sometime ago i did some work with Alpine Linux (s. here) and i was impressed how tiny this Linux distro was and how fast it was running.

So i decided after nearly 6 years of running an aircraft noise measuring station (for dfld.de) with Ubuntu to change to Alpine Linux.

This station runs a software on Java and needs RXTX, because the microphone is connected via USB and is read over /dev/ttyUSB0.

What is the problem with this setup?

• RXTX needs a Java which is running on glibc
• Alpine Linux does not run on glibc

If you are not aware of this problem, you get some errors like

./javaash: java: command not found

and this happens even if you are in the right directory and java got the execute bit configured.

Alpine Linux changed to musl:

There are some other libc implementations (take a look here).
The homepage is https://www.musl-libc.org/:

 And a comparison to other libc can be found at http://www.etalabs.net/compare_libcs.html:

There are some workarounds to get applications build with glibc running on Alpine Linux, but i did not get to run my aircraft noise measuring station - i switched to Debian - because i needed a 32bit Linux for my very old UMPC...

Oracle Cloud: Feature Set

For all readers, who want to get a short overview to the services which can be configured inside Oracle Cloud, here a walkthrough the menus.
The Main menu shows the following items:

• Core infrastructure
• Compute
• Block Storage
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• File Storage
• Networking 
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Inside the Compute item the following services can be found:

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The menu Database has no subitems.

For most of these services you can find documentation here:
https://docs.cloud.oracle.com/iaas/Content/home.htm