mailbox/plugin/deleted-messages-vault-cassandra/src/main/java/org/apache/james/vault/metadata/MetadataSerializer.java

/****************************************************************
 * Licensed to the Apache Software Foundation (ASF) under one   *
 * or more contributor license agreements.  See the NOTICE file *
 * distributed with this work for additional information        *
 * regarding copyright ownership.  The ASF licenses this file   *
 * to you under the Apache License, Version 2.0 (the            *
 * "License"); you may not use this file except in compliance   *
 * with the License.  You may obtain a copy of the License at   *
 *                                                              *
 *   http://www.apache.org/licenses/LICENSE-2.0                 *
 *                                                              *
 * Unless required by applicable law or agreed to in writing,   *
 * software distributed under the License is distributed on an  *
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY       *
 * KIND, either express or implied.  See the License for the    *
 * specific language governing permissions and limitations      *
 * under the License.                                           *
 ****************************************************************/

package org.apache.james.vault.metadata;

import java.util.Optional;

import javax.inject.Inject;

import org.apache.james.vault.dto.DeletedMessageWithStorageInformationConverter;
import org.apache.james.vault.dto.DeletedMessageWithStorageInformationDTO;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.datatype.jdk8.Jdk8Module;

class MetadataSerializer {
    private static final Logger LOGGER = LoggerFactory.getLogger(MetadataSerializer.class);

    private final ObjectMapper objectMapper;
    private final DeletedMessageWithStorageInformationConverter dtoConverter;

    @Inject
    MetadataSerializer(DeletedMessageWithStorageInformationConverter dtoConverter) {
        this.dtoConverter = dtoConverter;
        this.objectMapper = new ObjectMapper()
            .registerModule(new Jdk8Module())
            .setSerializationInclusion(JsonInclude.Include.NON_ABSENT);
    }

    Optional<DeletedMessageWithStorageInformation> deserialize(String payload) {
        return deserializeDto(payload)
            .flatMap(this::toDomainObject);
    }

    private Optional<DeletedMessageWithStorageInformationDTO> deserializeDto(String payload) {
        try {
            return Optional.of(objectMapper.readValue(payload, DeletedMessageWithStorageInformationDTO.class));
        } catch (Exception e) {
            LOGGER.error("Error deserializing JSON metadata", e);
            return Optional.empty();
        }
    }

    private Optional<DeletedMessageWithStorageInformation> toDomainObject(DeletedMessageWithStorageInformationDTO dto) {
        try {
            return Optional.of(dtoConverter.toDomainObject(dto));
        } catch (Exception e) {
            LOGGER.error("Error deserializing DTO", e);
            return Optional.empty();
        }
    }

    String serialize(DeletedMessageWithStorageInformation message) {
        DeletedMessageWithStorageInformationDTO dto = DeletedMessageWithStorageInformationDTO.toDTO(message);

        try {
            return objectMapper.writeValueAsString(dto);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
    }
}