import ch.codeblock.qrinvoice.QrInvoiceCodeParser;
import ch.codeblock.qrinvoice.model.ParseException;
import ch.codeblock.qrinvoice.model.QrInvoice;
import ch.codeblock.qrinvoice.model.validation.ValidationException;
import ch.codeblock.qrinvoice.model.validation.ValidationResult;
import ch.codeblock.qrinvoice.qrcode.DecodeException;

import java.io.InputStream;

// ...


// either provide an input stream or a byte array
final InputStream imageInputStream = ...;

try {
    final QrInvoice qrInvoice = QrInvoiceCodeParser.create().parse(imageInputStream);

    // access QR-Invoice structure
    final BigDecimal amount = qrInvoice.getPaymentAmountInformation().getAmount();

    // ...
} catch (DecodeException e) {
    // decoding error handling - e.g. qr code could be found in the given image
} catch (ParseException e) {
    // parsing exception handling
}

try {
    final QrInvoice qrInvoice = QrInvoiceCodeParser.create().parseAndValidate(imageInputStream);

    // access QR-Invoice structure
    final BigDecimal amount = qrInvoice.getPaymentAmountInformation().getAmount();

    // ...
} catch (DecodeException e) {
    // decoding error handling - e.g. qr code could be found in the given image
} catch (ParseException e) {
    // parsing exception handling
} catch (ValidationException e) {
    final ValidationResult validationResult = e.getValidationResult();
    // ...
}