Where to put a text file in Grails, and how to get the path

Question

I need to read in a .txt file into a groovy class in order to interrogate it line by line. But I am not sure what folder I put it into in my grails app, and how to get the path to it?

So far I have tried placing it under src and also in a new folder web-app/txt

and I have tried the the following to read it in

fileIn = new File('/lexicon.txt').text 

and

fileIn = new File('txt/lexicon.txt').text

to no avail.

Any body have any pointers?

Answer 1

Grails is a Java Web Application, so it will be compiled into a sigle file .war, with all files/classes/etc inside. Most Web containers do unpack war, but there are no any guaranteee, so it's not a good idea to use File to access this file as a file.

Btw, you can place your file into grails-app/conf, at this case it will be placed into classpath, and you'll be able to access it by using:

InputStream lexicon = this.class.classLoader.getResourceAsStream('lexicon.txt')

You could also put this file into a subdirectory, like grails-app/conf/data and load it as ***.getResourceAsStream('data/lexicon.txt')

Answer 2

You can put your file under web-app/

Example:

web-app/lexicon.txt

And then in your controller or service use grailsApplication:

class MyService {
    def grailsApplication
    public myMethod() {
        File myFile = grailsApplication.mainContext.getResource("lexicon.txt").file
    }
}

Hope this helps

Answer 3

You can use Spring's resource loading to access the file. With this method you can access the file from a Spring bean, which means Grails can autowire the resource in to its artifacts.

See below for the following steps examples

1. Place the file in grails-app/conf/.
2. Make a resource holder class in src/groovy
3. Add the resource holder as a Spring bean in grails-app/spring/resources.groovy
4. Then autowire and use the resource wherever you need it

Step 2:

package resource

import org.springframework.core.io.Resource

class ResourceHolder {
    Resource lexicon
}

Step 3:

beans = {
    lexiconHolder(resource.ResourceHolder) {
        lexicon = 'classpath:lexicon.txt'
    }
}

Step 4:

class AnyGrailsService {
    def lexiconHolder

    void aMethodUsingTheLexicon() {
        File lexicon = lexiconHolder.lexicon.file

        /* Do stuff with the lexicon */
    }

Answer 4

In Grails 2, you can use the Grails Resource Locator

class MyService {
    def grailsResourceLocator

    myMethod() {
        def fileIn = grailsResourceLocator.findResourceForURI('/txt/lexicon.txt').file
    }
}

Handy tip: to mock this in Spock, use GroovyPageStaticResourceLoader

@TestFor(MyService)
class MyServiceSpec extends Specification {
    def setup() {
        service.grailsResourceLocator = Mock(GroovyPageStaticResourceLocator)
    }
}