Logging Managment

[inbalzukerman]

Research upon a logging system for our project.
As discussed in our meeting, try to research first the classes Fault and Monitor from the Spartanizer project.

[RonGatenio]

started working on a wiki page for Log4j

[inbalzukerman]

@RonGatenio, can this issue be closed?

[RonGatenio]

not yet... I need read about slf4j first
@inbalzukerman

[inbalzukerman]

Let us know so we could start working on #146, #147, #148 😄

[RonGatenio]

@inbalzukerman
You can start working on those issues.
If we will change from Log4j to Slf4j, the changes to the code will be minor, because their syntax is identical.

[inbalzukerman]

Yay! Thank you 👍

[RonGatenio]

I changed the logger to slf4j (I'll explain why later). For now, this is the new syntax:

import org.slf4j.LoggerFactory;
import org.slf4j.Logger;

public class MyClass {
    private static Logger log = LoggerFactory.getLogger(MyClass.class);
}

Note that log4j is still accessible (slf4j uses log4j... again, I'll explain this later...). So avoid using it!

Also, there is no longer a fatal alert level 😢

---

The old syntax (for a remainder):

import org.apache.log4j.Logger;

public class MyClass {
    private static Logger log = Logger.getLogger(MyClass.class);
}

@inbalzukerman @EliaTraore @ylevv @roy-shchory @alexvitho

[RonGatenio]

Something nice about the logger...
You can log a string and an exception in the following way:

public void myFunc() {
   try {
      //...
   } catch (Exception e) {
      log.error("Big error, very bad!", e);
   }
}

This will log the string and the stack trace:

2017-04-08 03:40:02 ERROR [JavaFX Application Thread] api.SmartHouseApplication#myFunc (SmartHouseApplication.java:54) - Big error, very bad! 
java.lang.IllegalStateException: Location is not set.
	at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2434)
	//...
	at java.lang.Thread.run(Unknown Source)

#146 #147 #148

[RonGatenio]

Another thing, try to avoid System.out.println("...") in the code...
Use log.debug("...") instead