opensnap.repository.MongoRepository.java Source code

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Here is the source code for opensnap.repository.MongoRepository.java

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/*
 * Copyright 2002-2014 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
 *
 *      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 opensnap.repository;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.mongodb.async.client.MongoCollection;
import com.mongodb.async.client.MongoDatabase;
import opensnap.domain.Identifiable;
import org.bson.Document;
import org.bson.codecs.DocumentCodec;
import org.bson.codecs.EncoderContext;
import org.bson.json.JsonWriter;
import org.bson.types.ObjectId;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;

public abstract class MongoRepository<T extends Identifiable> {

    private final MongoCollection<Document> collection;
    private static final Logger logger = LoggerFactory.getLogger(MongoRepository.class);
    private final ObjectMapper mapper;
    private final Class<T> clazz;

    public MongoRepository(MongoDatabase db, ObjectMapper mapper, String collectionName, Class<T> clazz) {
        this.mapper = mapper;
        this.clazz = clazz;
        collection = db.getCollection(collectionName);
    }

    public CompletableFuture<T> insert(T elem) {
        CompletableFuture<T> future = new CompletableFuture<>();
        try {
            Document doc = Document.valueOf(mapper.writeValueAsString(elem));
            collection.insert(doc).register((result, e) -> {
                if (result != null && result.wasAcknowledged()) {
                    elem.setId(doc.getObjectId("_id"));
                    future.complete(elem);
                } else {
                    logger.error("Error while creating a new document in insert() : " + doc.toString(), e);
                    future.cancel(true);
                }
            });
        } catch (JsonProcessingException e) {
            logger.error("Error while creating element " + elem.toString() + " in insert()", e);
            future.cancel(true);
        }
        return future;
    }

    public CompletableFuture<T> getOne(String key, Object value) {
        CompletableFuture<T> future = new CompletableFuture<>();

        collection.find(new Document(key, value)).one().register((document, e) -> {
            try {
                if (document != null) {
                    future.complete(mapper.readValue(toJson(document), clazz));
                } else {
                    logger.error("No document with attribute " + key + "=" + value + " found", e);
                    future.cancel(true);
                }
            } catch (IOException ex) {
                logger.error("Error while parsing document in getOne() : " + document.toString(), ex);
                future.cancel(true);
            }
        });
        return future;
    }

    public CompletableFuture<T> getById(String id) {
        return this.getOne("_id", new ObjectId(id));
    }

    public CompletableFuture<List<T>> getSome(String key, Object value) {
        CompletableFuture<List<T>> future = new CompletableFuture<>();
        List<T> list = new ArrayList<>();

        collection.find(new Document(key, value)).forEach((document) -> {
            try {
                list.add(mapper.readValue(toJson(document), clazz));
            } catch (IOException e) {
                logger.error("Error while parsing document in getSome() : " + document.toString(), e);
            }
        }).register((result, e) -> future.complete(list));
        ;
        return future;
    }

    public CompletableFuture<List<T>> getAll() {
        CompletableFuture<List<T>> future = new CompletableFuture<>();
        List<T> list = new ArrayList<>();

        collection.find(Document.valueOf("{_id:{ $exists: true }}")).forEach((document) -> {
            try {
                list.add(mapper.readValue(toJson(document), clazz));
            } catch (IOException e) {
                logger.error("Error while parsing document in getAll() : " + document.toString(), e);
            }

        }).register((result, e) -> future.complete(list));
        return future;
    }

    public void remove(String id) {
        throw new UnsupportedOperationException("Remove operation not yet implemented in MongoDB async driver");
    }

    public CompletableFuture<Long> count(String key, Object value) {
        CompletableFuture<Long> future = new CompletableFuture<>();
        collection.find(new Document(key, value)).count().register((count, e) -> future.complete(count));
        return future;
    }

    private String toJson(Document document) {
        StringWriter writer = new StringWriter();
        new DocumentCodec().encode(new JsonWriter(writer), document, EncoderContext.builder().build());
        return writer.toString();
    }
}