org.apache.james.json.DTOConverter Maven / Gradle / Ivy

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package org.apache.james.json;

import java.util.Map;
import java.util.Optional;
import java.util.Set;
import java.util.function.Function;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;

public class DTOConverter {

    private final Map> typeToModule;
    private final Map, DTOModule> domainClassToModule;

    @SafeVarargs
    public static  DTOConverter of(DTOModule... modules) {
        return new DTOConverter<>(ImmutableSet.copyOf(modules));
    }

    public DTOConverter(Set> modules) {
        typeToModule = modules.stream()
            .collect(ImmutableMap.toImmutableMap(
                DTOModule::getDomainObjectType,
                Function.identity()));

        domainClassToModule = modules.stream()
            .collect(ImmutableMap.toImmutableMap(
                DTOModule::getDomainObjectClass,
                Function.identity()));
    }

    @SuppressWarnings("unchecked")
    public Optional toDTO(T domainObject) {
        return Optional
            .ofNullable(domainClassToModule.get(domainObject.getClass()))
            .map(module -> (DTOModule) module)
            .map(module -> module.toDTO(domainObject));
    }

    @SuppressWarnings("unchecked")
    public Optional toDomainObject(U dto) {
        String type = dto.getType();
        return Optional
            .ofNullable(typeToModule.get(type))
            .map(module -> (DTOModule) module)
            .map(DTOModule::getToDomainObjectConverter)
            .map(convert -> convert.convert(dto));
    }
}