1. GroupDocs Documentation
    2. /
    3. GroupDocs.Signature Product Family
    4. /
    5. GroupDocs.Signature for Java
    6. /
    7. Developer Guide
    8. /
    9. Advanced usage
    10. /
    11. Common
    12. /
    13. Subscribing for verification process events

    Subscribing for verification process events

    Signature class contains several events that are being called for different verification process stages

    • VerifyStarted to handle process start event. This event is occur once verify method is called
    • VerifyProgress to handle progress event. This event occurs each time on verifying each signature was completed.
    • VerifyCompleted to handle completion event. This event occurs once verify process was completed.    

    Here are the steps to subscribe for verification process with GroupDocs.Signature:

    • Define required handler delegates to process signing events.
    • Create new instance of Signature class and pass source document path or stream as a constructor parameter.
    • Subscribe for required events
    • Instantiate required VerifyOptions object 
    • Call verify method of Signature class instance and pass verify options in it .

    Implement method for VerifyStarted event

    GroupDocs.Signature expects ProcessStartEventHandler delegate to subscribe for VerifyStarted event

    private static void onVerifyStarted(Signature sender, ProcessStartEventArgs args)
{
    System.out.print("Verify process started at "+args.getStarted()+" with "+args.getTotalSignatures()+" total signatures to be put in document");
}

    Implement method for VerifyProgress event 

     private static void onVerifyProgress(Signature sender, ProcessProgressEventArgs args)
{
    System.out.print("Verify progress. Processed "+args.getProcessedSignatures()+" signatures. Time spent "+args.getTicks()+" mlsec");
}

    Implement method for VerifyCompleted event 

    private static void onVerifyCompleted(Signature sender, ProcessCompleteEventArgs args)
{
    System.out.print("Verify process completed at "+args.getCompleted()+" with "+args.getTotalSignatures()+" total signatures. Process took "+args.getTicks()+" mlsec");
}

    Subscribing for verification process events 

    private static void onVerifyStarted(Signature sender, ProcessStartEventArgs args)
{
    System.out.print("Verify process started at "+args.getStarted()+" with "+args.getTotalSignatures()+" total signatures to be put in document");
}
 
private static void onVerifyProgress(Signature sender, ProcessProgressEventArgs args)
{
    System.out.print("Verify progress. Processed "+args.getProcessedSignatures()+" signatures. Time spent "+args.getTicks()+" mlsec");
}
 
private static void onVerifyCompleted(Signature sender, ProcessCompleteEventArgs args)
{
    System.out.print("Verify process completed at "+args.getCompleted()+" with "+args.getTotalSignatures()+" total signatures. Process took "+args.getTicks()+" mlsec");
}
 
 
public static void run()
{   
 
    try {
        Signature signature = new Signature("sample.pdf");
        signature.VerifyStarted.add(new ProcessStartEventHandler() {
            public void invoke(Signature sender, ProcessStartEventArgs args) {
                onVerifyStarted(sender, args);
            }
        });
 
 
        signature.VerifyProgress.add(new ProcessProgressEventHandler() {
            public void invoke(Signature sender, ProcessProgressEventArgs args) {
                onVerifyProgress(sender, args);
            }
 
 
        });
        signature.VerifyCompleted.add(new ProcessCompleteEventHandler() {
            public void invoke(Signature sender, ProcessCompleteEventArgs args) {
                onVerifyCompleted(sender, args);
            }
        });
 
        TextVerifyOptions options = new TextVerifyOptions("John Smith");
        options.setAllPages(true);
 
        // verify document
        VerificationResult result = signature.verify(options);
        if (result.isValid())
        {
            System.out.print("\nDocument was verified successfully!");
    }
        else
        {
            System.out.print("\nDocument failed verification process.");
        }
 
    } catch (Exception e) {
        throw new GroupDocsSignatureException(e.getMessage());
    }
}

    More resources

    GitHub Examples 

    You may easily run the code above and see the feature in action in our GitHub examples:

    Free Online App 

    Along with full-featured .NET library we provide simple, but powerful free Apps.
    You are welcome to eSign PDF, Word, Excel, PowerPoint documents with free to use online GroupDocs Signature App.

    © Groupdocs 2001-2024. All Rights Reserved.