Using The Amazon Web Services (AWS) SDK To Create Pre-Signed S3 URLs With Path-Style Access

component
	output = false
	hint = "I define the application settings and event handlers."
	{

	// Setup the core application settings.
	this.name = hash( getCurrentTemplatePath() );
	this.applicationTimeout = createTimeSpan( 0, 0, 1, 0 );
	this.sessionManagement = false;

	// Here, we're adding the Amazon SDK for Java to the Java libraries that this
	// application knows about. This will make the SDK classes available to the
	// createObject() method.
	// --
	// NOTE: I am not sure that I actually need all of these classes; but, I get object
	// instantiating errors if I don't include some of them. As such, I'm just including
	// all of the JAR files that came with the AWS SDK download.
	this.javaSettings = {
		loadPaths = [
			"../aws/lib/",
			"../aws/third-party/aspectj-1.6/",
			"../aws/third-party/commons-codec-1.6/",
			"../aws/third-party/commons-logging-1.1.3/",
			"../aws/third-party/freemarker-2.3.18/",
			"../aws/third-party/httpcomponents-client-4.3/",
			"../aws/third-party/jackson-annotations-2.3.0/",
			"../aws/third-party/jackson-core-2.3.2/",
			"../aws/third-party/jackson-databind-2.3.2/",
			"../aws/third-party/javax-mail-1.4.6/",
			"../aws/third-party/joda-time-2.2/",
			"../aws/third-party/spring-3.0/"
		],

		// Allows createObject() to access libraries in the main ColdFusion class path.
		loadColdFusionClassPath = true
	};


	// ---
	// PUBLIC METHODS.
	// ---


	/**
	* I configure the application on startup.
	*
	* @output false
	*/
	public boolean function onApplicationStart() {

		var baseDirectory = getDirectoryFromPath( getCurrentTemplatePath() );

		var config = deserializeJson( fileRead( "#baseDirectory#../config.json" ) );

		// Make the AWS credentials globally available for the demo.
		application.aws = {
			region = config.aws.region,
			bucket = config.aws.bucket,
			accessID = config.aws.accessID,
			secretKey = config.aws.secretKey
		};

		// Return true so the application can load.
		return( true );

	}

}

<cfscript>

	// Set up the S3 client with the explicit credentials.
	s3Client = createObject( "java", "com.amazonaws.services.s3.AmazonS3Client" ).init(
		createObject( "java", "com.amazonaws.auth.BasicAWSCredentials" ).init(
			javaCast( "string", application.aws.accessID ),
			javaCast( "string", application.aws.secretKey )
		)
	);

	// Set the region (ex, "us-east-1") for the client. This will determine the endpoint
	// that the client will use to make API calls and pre-signed URLs.
	s3Client.setRegion(
		createObject( "java", "com.amazonaws.regions.Regions" ).fromName(
			javaCast( "string", application.aws.region )
		)
	);

	// Create the local (server time) for Epoch. This will make it easier to calculate
	// the expiration dates for the pre-signed URLs.
	localEpoch = dateConvert( "utc2local", "1970/01/01" );

	// Setup the expiration date for the pre-signed URLs.
	expiresAt = dateAdd( "h", 1, now() );


	// ------------------------------------------------------ //
	// ------------------------------------------------------ //


	// By default, the S3 client will use "virtual-hosted-style" URLs in which the bucket
	// name is part of the domain name used to define the URLs. This works fine if you
	// are generating HTTP URLs; but, if you intend to generate HTTPS (SSL) URLs (which
	// the client does by default), you can run into issues if your bucket name contains
	// periods (ex, "testing.bennadel.com). Amazon S3 only has a single wild-card SSL
	// certificate; as such, it can't validate for multi-level sub-domains.
	presignedUrl = s3Client.generatePresignedUrl(
		javaCast( "string", application.aws.bucket ),
		javaCast( "string", "sdk/pre-signed-urls/calm-face.jpg" ),
		createObject( "java", "java.util.Date" ).init(
			javaCast( "long", ( dateDiff( "s", localEpoch, expiresAt ) * 1000 ) )
		)
	);

	// Will use "https://testing.bennadel.com.s3.amazonaws.com/" as domain.
	writeOutput( presignedUrl & "<br />" );


	// ------------------------------------------------------ //
	// ------------------------------------------------------ //


	// We can tell our S3 client to forgo to the "virtual-hosted-style" URLs and use
	// the "path-style" access. With path-style access, the bucket name is part of the
	// path used to define the resource (it is the key prefix). This will use your
	// region-specific Amazon S3 endpoint (ex, s3.amazonaws.com) as the domain, which
	// will allow the URLs to work with the Amazon S3 certificate.
	s3Client.setS3ClientOptions(
		createObject( "java", "com.amazonaws.services.s3.S3ClientOptions" )
			.withPathStyleAccess( javaCast( "boolean", true ) )
	);

	// Generate the pre-signed URL (again).
	presignedUrl = s3Client.generatePresignedUrl(
		javaCast( "string", application.aws.bucket ),
		javaCast( "string", "sdk/pre-signed-urls/calm-face.jpg" ),
		createObject( "java", "java.util.Date" ).init(
			javaCast( "long", ( dateDiff( "s", localEpoch, expiresAt ) * 1000 ) )
		)
	);

	// Will use "https://s3.amazonaws.com/" as domain for us-east-1 region.
	writeOutput( presignedUrl & "<br />" );

</cfscript>