Using The Safe-Navigation Operator To Safely Clean Up Resources In Lucee 5.3.2.77

gzip.cfm

<cfscript>

	message = (
		"In the year of our Lord 1314, patriots of Scotland, starving and outnumbered, " &
		"charged the fields of Bannockburn. They fought like warrior poets. They fought " &
		"like Scotsmen and they won their freedom."
	);

	try {

		outputStream = createObject( "java", "java.io.ByteArrayOutputStream" ).init();
		gzipOutputStream = createObject( "java","java.util.zip.GZIPOutputStream" ).init( outputStream );

		// Write the message to the GZIP output stream.
		messageBytes = charsetDecode( message, "utf-8" );
		gzipOutputStream.write( messageBytes, 0, arrayLen( messageBytes ) );
		gzipOutputStream.finish();

		// Persist the GZIP binary data to a flat file.
		fileWrite( "./quote.txt.gzip", outputStream.toByteArray() );

	} finally {

		// Close all streams once we are done.
		// --
		// NOTE: In this case, it is extremely unlikely that these objects wouldn't
		// exist. However, this is a usage-pattern that I am starting to embrace - using
		// the SAFE NAVIGATION OPERATOR to safely close objects that were created within
		// the bounds of a try-block.
		gzipOutputStream?.close();
		outputStream?.close();

	}

	// FUN SIDE NOTE: You can easily extract this GZIP data using the extract() function:
	// --
	// extract( "gzip", "./quote.txt.gzip", "./quote.txt" );

</cfscript>

jedis.cfm

<cfscript>

	// ....

	try {

		jedis = jedisPool.getResource();

		jedis.set( "hello", "world" );

	} finally {

		// Once we are done interacting with Redis, we have to close the Jedis resource
		// or it won't be returned to the connection pool. Jedis will be NULL if a
		// resource could not be obtained from the connection pool.
		// --
		// NOTE: We are using the safe-navigation operator to safely close the resource
		// even if it wasn't obtained.
		jedis?.close();

	}	

</cfscript>

lock.cfm

<cfscript>

	try {

		distributedLock = getLock( "myLock" );

		// ... do some complicated stuff within this globally-synchronized block.
		echo( "Done." );

	} catch ( "DistributedLock.LockError" error ) {

		echo( "Someone else is already doing this thing!" );

	} finally {

		// Release the distributed lock once we are done with the synchronized work.
		// --
		// NOTE: We are using the safe-navigation operator so that we can safely call
		// this line of code even if we failed to obtain the distributed lock.
		distributedLock?.release();

	}

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

	/**
	* I obtain a mock distributed-lock.
	* 
	* @name I am the name of the lock being obtained.
	*/
	public any function getLock( required string name ) {

		if ( randRange( 0, 1 ) ) {

			throw( type = "DistributedLock.LockError" );

		}

		return({
			release: () => {
				// ... this is just a mock lock.
			}
		});

	}

</cfscript>