Uploading Files in Grails

Here's the slides from a presentation I did at the UGGUG in May 2010. I found that I needed to use it again today so I posted it.

Upload files with grails

View more presentations from Eric Berry.

Here is the source code for the uploader service I created:

	package berry
	import org.springframework.web.multipart.MultipartFile
	import org.codehaus.groovy.grails.web.context.ServletContextHolder
	class FileUploadService {
	boolean transactional = true
	def String uploadFile(MultipartFile file, String name, String destinationDirectory) {
	def servletContext = ServletContextHolder.servletContext
	def storagePath = servletContext.getRealPath(destinationDirectory)
	// Create storage path directory if it does not exist
	def storagePathDirectory = new File(storagePath)
	if (!storagePathDirectory.exists()) {
	print "CREATING DIRECTORY ${storagePath}: "
	if (storagePathDirectory.mkdirs()) {
	println "SUCCESS"
	} else {
	println "FAILED"
	}
	}
	// Store file
	if (!file.isEmpty()) {
	file.transferTo(new File("${storagePath}/${name}"))
	println "Saved file: ${storagePath}/${name}"
	return "${storagePath}/${name}"
	} else {
	println "File ${file.inspect()} was empty!"
	return null
	}
	}
	}

view raw FileUploadService.java hosted with ❤ by GitHub

A tip that you may enjoy is the way I implemented this uploader into a real world application. I wanted to be able to upload files into a folder within the web-app folder for development, but in production, I wanted to put it in a folder that is served via Tomcat directly. So on our production server, I created a folder at /opt/assets and created a symbolic link in the $TOMCAT_ROOT/webapps/assets to point to it. I modified the service as follows:

	package berry
	import org.springframework.web.multipart.MultipartFile
	import org.codehaus.groovy.grails.web.context.ServletContextHolder
	import grails.util.GrailsUtil
	class FileUploadService {
	boolean transactional = true
	def String uploadFile(MultipartFile file, String name) {
	String storagePath = ""
	if (GrailsUtil.environment == "production") {
	storagePath = "/opt/assets"
	} else {
	def servletContext = ServletContextHolder.servletContext
	storagePath = servletContext.getRealPath('assets')
	}
	// Create storage path directory if it does not exist
	def storagePathDirectory = new File(storagePath)
	if (!storagePathDirectory.exists()) {
	print "CREATING DIRECTORY ${storagePath}: "
	if (storagePathDirectory.mkdirs()) {
	println "SUCCESS"
	} else {
	println "FAILED"
	}
	}
	// Store file
	if (!file.isEmpty()) {
	file.transferTo(new File("${storagePath}/${name}"))
	println "Saved file: ${storagePath}/${name}"
	return "${storagePath}/${name}"
	} else {
	println "File ${file.inspect()} was empty!"
	return null
	}
	}
	}

view raw FileUploadService2.java hosted with ❤ by GitHub

I then create a folder in my web-app folder named 'assets', being sure to add it to my ignore list for the repository. So once I upload the file, it will save to the correct location.

Now to view the image, all I have to do is the following:

<img src="${resource(dir:'assets', file: 'myfile.jpg')}" />

view raw img.html hosted with ❤ by GitHub

This now will work in both DEVELOPMENT and PRODUCTION enviroments.

http://github.com/cavneb/FileUploader