com.github.nagyesta.lowkeyvault.model.json.util.Base64Deserializer Maven / Gradle / Ivy

Go to download
package com.github.nagyesta.lowkeyvault.model.json.util;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import org.springframework.util.StringUtils;

import java.io.IOException;
import java.util.Base64;
import java.util.Optional;

public class Base64Deserializer extends JsonDeserializer {
    private static final Base64.Decoder DECODER = Base64.getUrlDecoder();
    private final Base64.Decoder decoder;

    public Base64Deserializer() {
        this(DECODER);
    }

    protected Base64Deserializer(final Base64.Decoder decoder) {
        this.decoder = decoder;
    }

    @Override
    public byte[] deserialize(final JsonParser parser, final DeserializationContext context) throws IOException {
        return deserializeBase64(parser);
    }

    protected byte[] deserializeBase64(final JsonParser parser) throws IOException {
        final Optional optional = Optional.ofNullable(parser.readValueAs(String.class));
        if (optional.isEmpty()) {
            return null;
        }
        return optional
                .filter(StringUtils::hasText)
                .map(decoder::decode)
                .orElse(new byte[0]);
    }
}