Groovy - dumping object's properties

Marry Christmas! This is the Christmas Eve and what follows is a Christmas Present for you!

Have you ever used BeanUtils from Apache to query the properties of an object? Was that easy? Well I did that and what I ended up was completely unreadable and chaotic. But there's good news! Here's how it's doable in Groovy:

object.properties

That's it! Groovy exposes the map of properties as a predefined property called "properties". Ain't that cool? Let's see how we would go about printing all the values of object's properties along with their names:

println object.properties.collect{it}.join('\n')

Here's what it's doing: it gets the map of properties, turns it into a list (collect{it}) and joins them with a new line character.

Did you notice that "class" is also one of the properties? That's nasty! How about filtering it out?

println object.properties.findAll{it.key != 'class'}.join('\n')

Now that's much better, but good only for one or two names to filter. How about a more general solution?

def filtered = ['class', 'active']
println object.properties
.collect{it}
.findAll{!filtered.contains(it.key)}
.join('\n')

That's much much better but still, if the object has like 15 properties looking them up is a pain if they are not sorted. Let's do something about it:

def filtered = ['class', 'active']

println object.properties
.sort{it.key}
.collect{it}
.findAll{!filtered.contains(it.key)}
.join('\n')

And there it is! A list of key=value (value taken from object's toString()) separated by a new-line character for easier browsing :)

I hope this will help you out with your Groovy adventures!

Have a nice holiday!