New Blynk Server Release

Dear all,

since new 0.28.0 Blynk Server version you are required to update Java version from Java 8 to Java 9.

On Linux-like system you need to:

  1. sudo apt-get install oracle-java9-jdk
  2. Stop server;
  3. Run server;

On Windows:

  1. Download new Java 9;
  2. Install it;
  3. Stop server;
  4. Run server;

If you have any issues - please post it here.

You will see the error in case you are trying to run the latest server on java 8.

Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.UnsupportedClassVersionError: cc/blynk/server/launcher/ServerLauncher has been compiled by a more recent version of the Java Runtime (class file version 53.0), this version of the Java Runtime only recognizes class file versions up to 52.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(
	at Method)
	at java.lang.ClassLoader.loadClass(
	at sun.misc.Launcher$AppClassLoader.loadClass(
	at java.lang.ClassLoader.loadClass(
	at sun.launcher.LauncherHelper.checkAndLoadMain(

Migration required in order to decrease memory consumption and better performance.

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Lame, this update basically cuts out Synology NAS as server because no support for Java9.


Looks like I won’t be updating for a long time.

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@Jamin in case of many requests I may do a java 8 build so it will work on older java versions. I just haven’t time to do all in one release.

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A Java8 version would be handy. At least until Synology announce any news on Java9 support (so far no articals at all about it).

Ok. I created the ticket. Will take a look when I have free time. For now updating to 0.28.0 is not required as there were no changes on apps.

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No rush as the previous version is running my projects fine.

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Mmm… Java 9… I Will try to update my Orange Pi, not sure about the proper procedure… :disappointed_relieved: … for sure a good challenge for me due to my lack of knowledge about Linux… Fingers crossed!

Warning!! Linux No0b alert :stuck_out_tongue:

Even after running sudo apt-get update then sudo apt-get install oracle-java9-jdk, I get this error:

gunner@AspireOne ~ $ sudo apt-get install oracle-java9-jdk
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package oracle-java9-jdk

I am running Linux Mint (Ubuntu 14.04.5 LTS)

There is no Java9 for the ARM (e.g. Raspi) so it’s useless to try and update :slight_smile:

Ok guys. I found an easy way to make builds for Java 8 and Java 9. So we will release 2 builds every time.

For java 8


For java 9



You sir, are the best!!!

Ok Bro thanks you very much

Thanks @Dmitriy - I was wondering why I couldn’t install Java9 on my Rpi.

No need to bother, just use a dedicated java8 version.

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Because there is no ARM version yet released. Keep an eye out on the Oracle website for updates :slight_smile:

The Source Files is for which one(Java8 or 9)? Both should work. You may specify java8 profile as default in main pom.xml. (Right now default env is Java 9) -

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I recently updated to the latest Java 8 version, but it seems to crash after a few (aprox 6-8) hours…

I just have default logging and this is all that shows… any ideas? or do I need to change logging options?

21:20:04.340 ERROR- Unexpected error!!!
21:20:54.801 ERROR- Unexpected error!!!
21:21:58.025 ERROR- Handler class : class cc.blynk.server.application.handlers.main.auth.AppLoginHandler. Name : ALogin
21:21:58.026 ERROR- Handler class : class cc.blynk.server.hardware.handlers.hardware.HardwareHandler. Name : HHArdwareHandler
21:22:18.174 ERROR- Unexpected error!!!

Same issue here but only once and without the “ALogin” line