ColdFusion: ZXing - Read / Write QRCode Barcode Example

I have been slowly working my way through more of the zxing library. Since I did not find any CF examples in my searches, I am posting some of my code snippets in case it helps someone else.


Generate Barcode
To generate a barcode, I first created an instance of the QRCodeWriter. Then called its encode() method with four settings: the text to encode, barcode type and the desired width and height. The encode() method does it magic and returns a matrix of bytes. Next I used the MatrixToImageWriter class, and its toBufferedImage(), method to convert the matrix into something useful. Not surprisingly, it returns a BufferedImage which is easily converted to a CF image object.

Note: This example uses the JavaLoader.cfc

<!---
    Generate barcode
--->
<cftry>
    <cfset origText = "http://code.google.com/p/zxing/wiki/GettingStarted" />
    <!--- initialize writer and create a new barcode matrix --->
    <cfset BarcodeFormat = loader.create("com.google.zxing.BarcodeFormat") />
    <cfset writer = loader.create("com.google.zxing.qrcode.QRCodeWriter").init() />
    <cfset bitMatrix = writer.encode( origText, BarcodeFormat.QR_CODE, 80, 80 )>
    <!--- render the matrix as a bufferedimage --->
    <cfset converter = loader.create("com.google.zxing.client.j2se.MatrixToImageWriter")>
    <cfset buff = converter.toBufferedImage( bitMatrix ) />
    <!--- convert it to a CF compatible image --->
    <cfset img = ImageNew( buff ) />

    <!--- display results --->
    <b>Original Text = </b> <cfoutput>#origText#</cfoutput>
    <div>
        <cfimage action="writeToBrowser" source="#img#" format="png">
    </div>
    <!--- add real exception handling here ...--->
    <cfcatch>
        ERROR: Unable to generate barcode <cfoutput>#cfcatch.message#</cfoutput>
    </cfcatch>
</cftry>

Read Barcode
Now to read / decode, I passed the BufferedImage into a series of classes that attempt to locate a barcode within an image and essentially extract it into matrix of bits. Finally, I passed the matrix into a QRCodeReader for decoding and voila - it returned the decoded text.

Result:

<!---
    Decode barcode
--->
<cftry>
    <!--- extract the BufferedImage of the current barcode --->
    <cfset buff = ImageGetBufferedImage( img ) />
    <!--- prepare the image for decoding --->
    <cfset source = loader.create("com.google.zxing.client.j2se.BufferedImageLuminanceSource").init( buff ) />
    <cfset binarizer = loader.create("com.google.zxing.common.GlobalHistogramBinarizer").init( source ) />
    <cfset bitmap = loader.create("com.google.zxing.BinaryBitmap").init( binarizer ) />
    <cfset reader = loader.create("com.google.zxing.qrcode.QRCodeReader").init() />
    <!--- decode the barcode. skipping "hints" just for simplicity --->
    <cfset decodedResult = reader.decode( bitmap, javacast("null", "")) />
    
    <!--- display results --->
    <b>Decoded Text = </b> <cfoutput>#decodedResult.getText()#</cfoutput>

    <!--- add real exception handling here ...--->
    <cfcatch>
        ERROR: Unable to generate barcode <cfoutput>#cfcatch.message#</cfoutput>
    </cfcatch>
</cftry>

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