javadev / pt-backend

import java.util.Base64;

import org.springframework.stereotype.Component;

import org.springframework.validation.Errors;

import org.springframework.validation.Validator;

@Component

public class DataurlValidator implements Validator {

    private static final String BASE64_PREFIX = ";base64,";

    private static final int BASE64_PREFIX_LENGTH = 8;

    @Override

    public void validate(final Object obj, final Errors errors) {

        final String dataUrl = (String) obj;

        if (dataUrl != null) {

            try {

                final String encodedString =

                        dataUrl.substring(dataUrl.indexOf(BASE64_PREFIX) + BASE64_PREFIX_LENGTH)

                                .replaceAll("\\s+", "");

                int length = Base64.getDecoder().decode(encodedString).length;

                if (length > 2097152) {

                    errors.reject("dataUrl", "Image cannot be large than 2 megabytes");

                }

            } catch (Exception ex) {

                errors.reject("dataUrl", "Invalid dataUrl");

            }

        }

    }

}