How to generate barcode and sign document using Java Leave feedback

Barcodes represent textual information as a quite small image that could be automatically scanned. Such an approach brings new opportunities in the computer processing of documents like sorting or moving through a business workflow. In this article, we will discuss useful ways to sign electronic documents with data encrypted in Bar or QR codes using Java.

GroupDocs.Signature for Java provides API for signing a wide range of document formats. Moreover, API includes special abilities for additional document content processing. Supported formats are PDF, Microsoft Word, Microsoft PowerPoint, Microsoft Excel, PNG, JPEG, and many others.

Use the downloads section to obtain the API JAR, or add the com.groupdocs:groupdocs-signature dependency from the GroupDocs Artifact Repository to your Maven project as described in Installation:

<dependency>
    <groupId>com.groupdocs</groupId>
    <artifactId>groupdocs-signature</artifactId>
    <version>26.10</version>
</dependency>

It is a common problem to add additional data to various types of business documents. Such a document may look as in the picture below. One of the most useful ways is to place a barcode directly on the document page.

To generate a barcode and sign a particular document with it:

• Instantiate the Signature class providing a path to the source document or document stream.
• Create the BarcodeSignOptions instance and set up all demanded fields.
• Invoke the sign method to process the document, providing the output file path and sign options.

// instantiating the signature object
Signature signature = new Signature("source.pdf");
try {
    // setup barcode signature options
    BarcodeSignOptions signOptions = new BarcodeSignOptions();
    signOptions.setHorizontalAlignment(HorizontalAlignment.Right);
    signOptions.setTop(150);
    signOptions.setEncodeType(BarcodeTypes.Codabar);
    signOptions.setText("Approved_19/06/2022");

    // sign document
    signature.sign("signed_codabar.pdf", signOptions);
} finally {
    signature.dispose();
}

A document signed with a Codabar might look like in the picture below. The Codabar format was developed for printed documents and might be useful in office document flow.

The Barcode Generator Online App provides an opportunity to try document signing with barcodes for free.

Another way to improve documents is to generate the barcode first and then add it to documents using third-party tools. For this case, it is possible to generate code as an image.

• Create the BarcodeSignOptions class instance and set up all the demanded fields.
• Instantiate the PreviewSignatureOptions object, passing a PageSignatureStreamFactory implementation that creates and releases the output stream.
• Invoke the static Signature.generateSignaturePreview method to write the barcode image to the stream.
• Use the resultant barcode image in any possible way.

final ByteArrayOutputStream result = new ByteArrayOutputStream();

// setup barcode signature options
BarcodeSignOptions signOptions = new BarcodeSignOptions();
signOptions.setEncodeType(BarcodeTypes.Code93);
signOptions.setText("Case 148.01");

// instantiate preview options
PreviewSignatureOptions previewOptions = new PreviewSignatureOptions(signOptions,
        new PageSignatureStreamFactory() {
            @Override
            public OutputStream createSignatureStream(PreviewSignatureOptions options) {
                return result;
            }

            @Override
            public void closeSignatureStream(PreviewSignatureOptions options, OutputStream signatureStream) {
                // the stream stays open: the image is read from it below
            }
        });
previewOptions.setPreviewFormat(PreviewFormats.PNG);

// generate image to stream
Signature.generateSignaturePreview(previewOptions);

// use the image, for example save it to a file
Files.write(Paths.get("barcode.png"), result.toByteArray());

An image containing the generated barcode might look in this way:

In order to use the API without evaluation limitations, you can get a free temporary license.

To sum up, some useful ways of processing documents and barcodes were discussed in this article. Using GroupDocs.Signature in Java applications improves the productivity of such actions dramatically. In addition, you can use the Barcode Generator Online App to generate barcodes and/or sign your files with barcodes for free.

Read the documentation to learn how to use GroupDocs.Signature in your Java applications. Also, you may discuss any questions or issues at the GroupDocs forum.

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