Tips & Tricks - Create QR codes

QR codes are small pictures that usually represent a URL. When the QR code is photographed or viewed in specialized apps, the user can navigate to the URL. The Java library ZXing provides you with the ability to create QR codes yourself. This article shows how to integrate this library and use it with Groovy to convert input into a QR code.

You can download the sample application here. You can then import them as usual.

The import file also contains a process that must be included in the import. The process is deactivated after the import. If you would like to test this Tips & Tricks article, activate the process.

Activate the expert options so that all dialogs mentioned in this example are accessible. Background knowledge in Groovy are an advantage in this workshop.

Incorporate the library

First, the library must be downloaded from https://repo1.maven.org/maven2/com/google/zxing/core/3.1.0/core-3.1.0.jar and made available to Intrexx. As the file name is not very meaningful, the file is renamed to "zxing-3.1.0.jar". Copy the file to the portal directory "lib/extensions".

Now the portal needs to be informed where it should search for this library. The "portal.wcf" file, which can be found in the portal directory internal/cfg, is edited for this purpose. Add the last line at the bottom of this section:

            # Java Classpath (include wrapper.jar)  Add class path elements as
#  needed starting from 1
wrapper.java.classpath.1=<Intrexx-installation-directory>\lib\update
wrapper.java.classpath.2=<Intrexx-installation-directory>\lib\*.jar
wrapper.java.classpath.3=<Intrexx-installation-directory>\lib\remote\*.jar
wrapper.java.classpath.4=<Intrexx-installation-directory>\derby\lib\*.jar
wrapper.java.classpath.5=<Intrexx-installation-directory>\lib\extensions\*.jar

        

It is important to increment the value in wrapper.java.classpath.* as a consecutive number. Afterwards, restart the portal service.

Application

Here is the edit page of the example application where the URL can be entered and saved. The data group contains the file data field "Image".

On the "Overview" page, you will find a view table that displays the data from the data group. If you edit the "Image" column, you will see that a template for displaying the QR code in the table is selected here.

Process

In the associated process, there is a data group event handler that reacts to the insertion of data records into the data group of the sample application.

A Groovy script action is connected to the event handler with the following Groovy script:

            import java.awt.Color
import java.awt.Graphics2D
import java.awt.image.BufferedImage
import java.io.File
import java.util.Hashtable

import javax.imageio.ImageIO
import com.google.zxing.BarcodeFormat
import com.google.zxing.EncodeHintType
import com.google.zxing.common.BitMatrix 
import com.google.zxing.qrcode.QRCodeWriter
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel

//URL to be converted
String recURL = g_record["5BD2494E2A4BD0AD0C427262CE4882C61F639EF3"].value /* datafield URL <string> */ 

//Size of the image in pixels 
int size = 125 

//Set error correction level 
Hashtable<EncodeHintType, ErrorCorrectionLevel> hintMap = new Hashtable<EncodeHintType, ErrorCorrectionLevel>() 
hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L) 

//Initialize QR Code Writer 
QRCodeWriter qrCodeWriter = new QRCodeWriter() 

//Calculate QR code from URL 
BitMatrix byteMatrix = qrCodeWriter.encode(recURL,BarcodeFormat.QR_CODE, size, size, hintMap) 

//Adapt length unit of the image to QR code 
int CrunchifyWidth = byteMatrix.getWidth() 

BufferedImage image = new BufferedImage(CrunchifyWidth, CrunchifyWidth,BufferedImage.TYPE_INT_RGB)
image.createGraphics()
Graphics2D graphics = (Graphics2D) image.getGraphics() 

//Color the entire image white
graphics.setColor(Color.WHITE)
graphics.fillRect(0, 0, CrunchifyWidth, CrunchifyWidth) 

//Change color to black
graphics.setColor(Color.BLACK)

//Read black points and set to image 
for (int i = 0; i < CrunchifyWidth; i++) 
{
    for (int j = 0; j < CrunchifyWidth; j++) 
	{
        if (byteMatrix.get(i, j)) {
            graphics.fillRect(i, j, 1, 1)
        }
    }
}

// Convert image to image file
String fileType = "png"
String filePath = "internal/tmp/qrcode-${g_record.getRecId()}.png"
File qrFile = new File(filePath)
ImageIO.write(image, fileType, qrFile)

//Move image to data group
g_dgFile.move(guid: "F80E0F688327BCF0D35A91E5B4930E731861CCA4", id: g_record.getRecId(), file: qrFile, deleteAlways: true, triggerWorkflow: false)
        

If you want to use the script in other applications, please replace the GUID "5BD2494E2A4BD0AD0C427262CE4882C61F639EF3" with the GUID of your URL data field and the GUID "F80E0F688327BCF0D35A91E5B4930E731861CCA4" with the GUID of your image file data field.

Application in the browser

When you open the application in the browser, enter a URL on the input page and save it, a QR code is automatically generated and displayed on the "Overview" page. This image can then be copied to the clipboard from here, for example.