When comparing N2O vs Java, the Slant community recommends N2O for most people. In the question“What are the best backend web frameworks?” N2O is ranked 29th while Java is ranked 42nd.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Fast binary data
Pro Binary encoding and protocols
Here is a list of types of endpoints which are supported by EMQ and accesible to N2O apps: WebSockets, MQTT, MQTT-SN, TCP, UDP, CoAP. Normal use of N2O as a Web Framework or a Web Application Server is through WebSockets, but for IoT and MQTT applications it could be served through UDP or SCTP protocols providing application level message delivery consistency.
Pro Verbosity
It makes it easy to debug and to read code.
Pro Mature ecosystem
The language and all its tools have enough time to age and they've aged well.
Pro Type-safe
It is easier to catch errors sooner.
Cons
Con Unfriendly developer community
Developers are often rude and unfriendly to users.
Con Bad documentation
It has bad documentation, which leaves out crucial steps, making it hard to learn.
Con Memory hungry
Running the virtual machine, application server and application itself consumes significant amount of resources.
Con Unnecessarily obtuse and verbose
If you like typing 40 lines of code to open a file, Java is the language for you. If, on the other hand, you’d actually like to get something done, look elsewhere.
Con Oracle
Enough said.
In more detail: Oracle has acquired Java from Sun and continues to surround it with controversy ever since (legendary lawsuit with google, money extortion from the enterprise users etc.).