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    • com.toedter.spring.hateoas.jsonapi.AbstractJsonApiModelDeserializer Maven / Gradle / Ivy

    /*
 * Copyright 2020 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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 com.toedter.spring.hateoas.jsonapi;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.BeanProperty;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.deser.ContextualDeserializer;
import com.fasterxml.jackson.databind.deser.std.ContainerDeserializerBase;
import com.fasterxml.jackson.databind.type.TypeFactory;
import lombok.extern.slf4j.Slf4j;
import org.springframework.hateoas.mediatype.JacksonHelper;
import org.springframework.lang.Nullable;

import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

@Slf4j
abstract class AbstractJsonApiModelDeserializer extends ContainerDeserializerBase
        implements ContextualDeserializer {

    private final ObjectMapper mapper = new ObjectMapper();
    protected final JavaType contentType;

    AbstractJsonApiModelDeserializer() {
        this(TypeFactory.defaultInstance().constructSimpleType(JsonApiDocument.class, new JavaType[0]));
    }

    protected AbstractJsonApiModelDeserializer(JavaType contentType) {
        super(contentType);
        this.contentType = contentType;
    }

    @Override
    public T deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
        JsonApiDocument doc = p.getCodec().readValue(p, JsonApiDocument.class);
        if (doc.getData() != null && doc.getData() instanceof Collection) {
            List> collection = (List>) doc.getData();
            List resources = collection.stream()
                    .map(this::convertToResource)
                    .collect(Collectors.toList());
            return convertToRepresentationModel(resources, doc);
        }
        HashMap data = (HashMap) doc.getData();
        final Object objectFromProperties = convertToResource(data);
        return convertToRepresentationModel(Collections.singletonList(objectFromProperties), doc);
    }

    private @Nullable Object convertToResource(@Nullable HashMap data) {
        if (data == null) {
            return null;
        }

        Map attributes = (Map) data.get("attributes");

        JavaType rootType = JacksonHelper.findRootType(this.contentType);
        Object objectFromProperties;
        if( attributes != null) {
            objectFromProperties = mapper.convertValue(attributes, rootType.getRawClass());
        } else {
            try {
                objectFromProperties = rootType.getRawClass().getDeclaredConstructor().newInstance();
            } catch (Exception e) {
                log.error("Cannot convert data to resource.");
                e.printStackTrace();
                return null;
            }
        }
        JsonApiResourceIdentifier.setJsonApiResourceFieldAttributeForObject(
                objectFromProperties, JsonApiResourceIdentifier.JsonApiResourceField.id, (String) data.get("id"));
        JsonApiResourceIdentifier.setJsonApiResourceFieldAttributeForObject(
                objectFromProperties, JsonApiResourceIdentifier.JsonApiResourceField.type, (String) data.get("type"));
        return objectFromProperties;
    }

    abstract protected T convertToRepresentationModel(List resources, JsonApiDocument doc);

    @Override
    public JavaType getContentType() {
        return this.contentType;
    }

    @Override
    @Nullable
    public JsonDeserializer getContentDeserializer() {
        return null;
    }

    @Override
    public JsonDeserializer createContextual(DeserializationContext ctxt, BeanProperty property) {
        JavaType type = property == null ? ctxt.getContextualType() : property.getType().getContentType();
        return createJsonDeserializer(type);
    }

    abstract protected JsonDeserializer createJsonDeserializer(JavaType type);
}
    
    
    
    

    




    
    
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