Hi all, my name is Hubert A. Klein Ikkink. Not a very common name, right? To make things easier I just picked the first letters of my firstname and surname and came up with haki. So there you have it, now I am also known as Mr. Haki or mrhaki for short. You can read more blog postings at www.mrhaki.com. I am a passionate Groovy and Java developer based in Tilburg, The Netherlands. My goal is to write clean, elegant, user-centered and high quality software. You can find me on Google+ and Twitter. Hubert is a DZone MVB and is not an employee of DZone and has posted 160 posts at DZone. You can read more from them at their website. View Full User Profile

Groovy Goodness: GString as Writable

04.07.2014
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The Groovy API has the interface Writable. Classes that implement this interface are capable of writing their selves to a java.io.Writer object. The interface has one method writeTo() where the code is that writes the contents to a given Writer instance. Most implementations will also use the implementation of the writeTo() method in their toString() implementation.

The GString implementation in Groovy also implements the Writable interface. This means we can redirect the GString contents to some Writerinstance if we want to. In the following code we use a FileWriter to write the contents of a GString to a file:

def data = [
    new Expando(id: 1, user: 'mrhaki', country: 'The Netherlands'),
    new Expando(id: 2, user: 'hubert', country: 'The Netherlands'),
]

data.each { userData ->
    new File("${userData.id}.txt").withWriter('UTF-8') { fileWriter ->
        // Use writeTo method on GString to save
        // result in a file.
        "User $userData.user lives in $userData.country".writeTo(fileWriter)
    }
}


assert new File('1.txt').text == 'User mrhaki lives in The Netherlands'
assert new File('2.txt').text == 'User hubert lives in The Netherlands'


Published at DZone with permission of Hubert Klein Ikkink, author and DZone MVB. (source)

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