Grails: How do I print in the cmd console?

Question

I wanna print a few values in the console, how do I do this?

Every time I get into a function, I want it to print a line with whatever text, I just wanna know if I'm getting into the function, and for some if-else statements. Mostly for debugging.

Solution 1

you might want to consider grails built in logging functionality which provides the same functionality as println plus more

http://grails.github.io/grails-doc/3.0.x/guide/single.html#logging

in your app just say

log.info "Hello World"

to print something everytime you enter an action in a controller you can do something like this

class UserController {

    def beforeInterceptor = {
       log.info "Entering Action ${actionUri}"
    }

    def index = {
    }

    def listContributors = {
    }
}

this will print out to the log whenever the controller methods are entered because of the controller interceptor

Solution 2

If you mean "print to the console output panel", then you simply need to use println:

println "Hello, world"

Results in printed output:

groovy> println "Hello, world" 

Hello, world

If that's not what you mean, can you clarify your question to be more specific?

Solution 3

The regular java System.out.println("Your stuff"); works too.

Comments

[L_7337]

This will work in Controllers and Services, but it does not get automatically injected in to your own custom classes. You can either manually inject it, or just use println

[John Little]

I tried log.info("hello") in my controller, but nothing comes out on the console (of eclise with GTS), and there are no log directories or similar. Anyone know how to do this?

[Dem Pilafian]

@JohnLittle, log.info("hello") probably didn't display because of the logging level for your application, but log.println("hello") and log.error("hello") probably will display.

[TBAR]

For domain classes you will have to implement the toString method otherwise it won't know how to print it.