Tag Archives: pdf

Intelligent Mail barcode – iText and barcode4j

I use a java library called iText to create PDFs and do other PDF related tasks when I am building web applications, and i embed a lot of barcodes for various purposes. iText handles most of these very well, but I recently needed to replace the old USPS barcode (postnet) with the new barcode (intelligent mail). iText doesn’t support it, but with some helpful direction I implemented it using another library called barcode4j.  Here’s the method I wrote that you can pretty much copy and use directly:

/**
* Create a USPS Intelligent Barcode using Barcode4J and add it to iText document.
* @param code barcode value
* @param cb overcontent from stamper
* @param fieldPositions stamper.getAcroFields().getFieldPositions(“…”) for the placeholder field in PDF template
*/
public static void createUspsIntelligentBarcode(String code, PdfContentByte cb, float[] fieldPositions) {

if ((code.length() != 20) && (code.length() != 25) && (code.length() != 29) && (code.length() != 31)) {
throw new RuntimeException(“UspsIntelligentBarcode: code length of ” + code.length() + ” is invalid.”);
}

//Note: fieldPositions data = [page, llx, lly, urx, ury]
float height = (fieldPositions[4]-fieldPositions[2]);
float width = (fieldPositions[3]-fieldPositions[1]);

PdfTemplate tp = cb.createTemplate(width, height);

// Create the graphics and canvas objects that will contain the barcode.
Graphics2D g2 = tp.createGraphics(width, height);
g2.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
g2.scale(2.5, 2.835); // (1mm == 2.835 points) + tweaking on x to make bar width correct
Java2DCanvasProvider provider = new Java2DCanvasProvider(g2, 0);

// Create Barcode4J barcode on canvas
USPSIntelligentMailBean barcode = new USPSIntelligentMailBean();
// use 70% of converted values.  Measurements on printouts needed to be tweaked.
barcode.setAscenderHeight(UnitConv.in2mm(0.1f) * 0.7f);  // height of ascender/descender per USPS spec
barcode.setTrackHeight(UnitConv.in2mm(0.05f)* 0.7f);      // height of track bar per USPS spec (smallest bar of barcode)
barcode.setBarHeight(UnitConv.in2mm(0.145f)* 0.7f);
barcode.setIntercharGapWidth(UnitConv.in2mm(0.04f)* 0.7f * 1.13f); // adjust again for scaling
barcode.generateBarcode(provider, code);

g2.dispose();

// adjust x/y to perfect location for envelope window
float inch = 72f; // itext manual pg 33
float xCoordinate = fieldPositions[1] – ((1f/8f) * inch);
float yCoordinate = fieldPositions[2] – ((3f/32f) * inch);

cb.addTemplate(tp, xCoordinate, yCoordinate);
}

This lets you put the intelligent mail barcode (or any barcode in barcode4j) directly into iText.  The key here is that the PdfTemplate in iText has a method that creates a generic Java Graphics2D object that is accessible for drawing by anything.  This generic object is exactly what is needed to be passed into the barcode4j canvas provider, and then any barcode4j barcode is output to the canvas.  A couple tweaks to position it however it is needed, and that is it.  It was a lot simpler than I expected when I realized I couldn’t just use iText for the whole thing.  Gotta love open source!