JacksonObjectIdUpdater.java

/*
 * Copyright (C) 2011 Benoit GUEROUT <bguerout at gmail dot com> and Yves AMSELLEM <amsellem dot yves at gmail dot com>
 *
 * 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
 *
 *     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.jongo.marshall.jackson;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.introspect.AnnotatedMember;
import com.fasterxml.jackson.databind.introspect.BasicBeanDescription;
import com.fasterxml.jackson.databind.introspect.BasicClassIntrospector;
import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
import org.bson.types.ObjectId;
import org.jongo.ObjectIdUpdater;
import org.jongo.marshall.jackson.oid.Id;
import org.jongo.marshall.jackson.oid.MongoId;
import org.jongo.marshall.jackson.oid.MongoObjectId;

/**
 * An ObjectIdUpdater based on Jackson's view of on object.
 *
 * @author Christian Trimble
 */
@SuppressWarnings("deprecation")
public class JacksonObjectIdUpdater implements ObjectIdUpdater {

    private final ObjectMapper mapper;

    public JacksonObjectIdUpdater(ObjectMapper mapper) {
        this.mapper = mapper;
    }

    public boolean mustGenerateObjectId(Object pojo) {
        for (BeanPropertyDefinition def : beanDescription(pojo.getClass()).findProperties()) {
            if (isIdProperty(def)) {
                AnnotatedMember accessor = def.getAccessor();
                accessor.fixAccess();
                return isObjectId(def) && accessor.getValue(pojo) == null;
            }
        }
        return false;
    }

    public Object getId(Object pojo) {
        BasicBeanDescription beanDescription = beanDescription(pojo.getClass());
        for (BeanPropertyDefinition def : beanDescription.findProperties()) {
            if (isIdProperty(def)) {
                AnnotatedMember accessor = def.getAccessor();
                accessor.fixAccess();
                Object id = accessor.getValue(pojo);
                if (id instanceof String && isObjectId(def)) {
                    return new ObjectId(id.toString());
                } else {
                    return id;
                }
            }
        }
        return null;
    }

    public void setObjectId(Object target, ObjectId id) {
        for (BeanPropertyDefinition def : beanDescription(target.getClass()).findProperties()) {
            if (isIdProperty(def)) {
                AnnotatedMember accessor = def.getAccessor();
                accessor.fixAccess();
                if (accessor.getValue(target) != null) {
                    throw new IllegalArgumentException("Unable to set objectid on class: " + target.getClass());
                }
                AnnotatedMember field = def.getField();
                field.fixAccess();
                Class<?> type = field.getRawType();
                if (ObjectId.class.isAssignableFrom(type)) {
                    field.setValue(target, id);
                } else if (type.equals(String.class) && isObjectId(def)) {
                    field.setValue(target, id.toString());
                }
                return;
            }
        }
    }

    private static boolean isIdProperty(BeanPropertyDefinition property) {
        return hasIdName(property) || hasIdAnnotation(property);
    }

    private static boolean isObjectId(BeanPropertyDefinition property) {
        return property.getPrimaryMember().getAnnotation(org.jongo.marshall.jackson.oid.ObjectId.class) != null
                || property.getPrimaryMember().getAnnotation(MongoObjectId.class) != null
                || ObjectId.class.isAssignableFrom(property.getAccessor().getRawType());
    }

    private static boolean hasIdName(BeanPropertyDefinition property) {
        return "_id".equals(property.getName());
    }

    private static boolean hasIdAnnotation(BeanPropertyDefinition property) {
        if (property == null) return false;
        AnnotatedMember accessor = property.getPrimaryMember();
        return accessor != null && (accessor.getAnnotation(MongoId.class) != null || accessor.getAnnotation(Id.class) != null);
    }

    private BasicBeanDescription beanDescription(Class<?> cls) {
        BasicClassIntrospector bci = new BasicClassIntrospector();
        return bci.forSerialization(mapper.getSerializationConfig(), mapper.constructType(cls), mapper.getSerializationConfig());
    }
}