can anyone explain me about what is the difference between log.utils error, log.error, log.info and ExceptionLog error?

Question

anyone explain me about why and where we use log.info and log.error and logUtils.error and ExceptionLog error. we can also use system.out.println for printing but why we use logs for printing and why we have these many of logs?

Answer 1

Generally we don't use println for logging because there are libraries that are much better at that and configurable. println means that the message is going to be printed to standard output every time, but logging libraries let us define configuration file, outside of code, that defines what log level we want to log to which output for example send it over the network or save it into the file, we can choose the layout of on log line and customize it to get information that is meaningful to us and this is just part of configuration capabilities. Basically we want as much freedom of logging configuration without changing the code as possible. That allows us to define different behaviors across different environments, different configuration for each package etc and helps us to stay consistent throughout whole application.

Practical example is my production application that logs to central log server and send logs over network, besides that it just logs to console, but in my development environment it logs to a file directly. So I can build application in my development environment and deploy it in production without thinking about logging because it depends on the configuration file.