com.sangupta.urn.service.impl.MongoGridFSUrnStorageServiceImpl.java Source code

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Here is the source code for com.sangupta.urn.service.impl.MongoGridFSUrnStorageServiceImpl.java

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/**
 *
 * urn - Object Storage Library
 * Copyright (c) 2016, Sandeep Gupta
 * 
 * http://sangupta.com/projects/urn
 * 
 * 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 com.sangupta.urn.service.impl;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.mongodb.gridfs.GridFsTemplate;

import com.mongodb.BasicDBObject;
import com.mongodb.DBObject;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSFile;
import com.sangupta.jerry.util.AssertUtils;
import com.sangupta.urn.model.UrnObject;
import com.sangupta.urn.service.UrnStorageService;

/**
 * A MongoDB GridFS based implementation for {@link UrnStorageService}.
 * 
 * @author sangupta
 *
 */
public class MongoGridFSUrnStorageServiceImpl extends AbstractUrnStorageServiceImpl {

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

    private static final String FIELD_EXPIRY = "expiry";

    private static final String FIELD_MIME = "mime";

    private static final String FIELD_STORED = "stored";

    private static final String FIELD_NAME = "name";

    private final GridFsTemplate template;

    public MongoGridFSUrnStorageServiceImpl(GridFsTemplate template) {
        this.template = template;
    }

    @Override
    protected UrnObject get(String objectKey) {
        Query query = new Query(Criteria.where("filename").is(objectKey));
        GridFSDBFile file = this.template.findOne(query);
        if (file == null) {
            return null;
        }

        // check for expiry
        Long expiry = (Long) file.get(FIELD_EXPIRY);
        if (expiry != null) {
            if (expiry.longValue() < System.currentTimeMillis()) {
                this.remove(objectKey);
                return null;
            }
        }

        byte[] bytes = null;
        try {
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            file.writeTo(stream);
            stream.close();
            bytes = stream.toByteArray();
        } catch (IOException e) {
            LOGGER.error("Error reading file from mongo database for key: " + objectKey, e);
            return null;
        }

        UrnObject urnObject = new UrnObject(objectKey, bytes);

        // now the metadata
        if (expiry != null) {
            urnObject.expiry = expiry.longValue();
        }

        urnObject.name = (String) file.get(FIELD_NAME);
        urnObject.mime = file.getContentType();
        urnObject.stored = file.getUploadDate().getTime();

        // return the object
        return urnObject;
    }

    @Override
    protected String save(UrnObject urnObject) {
        ByteArrayInputStream stream = new ByteArrayInputStream(urnObject.bytes);

        DBObject metadata = new BasicDBObject();
        metadata.put(FIELD_STORED, urnObject.stored);

        if (AssertUtils.isNotEmpty(urnObject.name)) {
            metadata.put(FIELD_NAME, urnObject.name);
        }
        if (AssertUtils.isNotEmpty(urnObject.name)) {
            metadata.put(FIELD_MIME, urnObject.mime);
        }
        if (urnObject.expiry > 0) {
            metadata.put(FIELD_EXPIRY, urnObject.expiry);
        }

        GridFSFile file = this.template.store(stream, urnObject.key, urnObject.mime, metadata);
        if (file == null) {
            return null;
        }

        return file.getFilename();
    }

    @Override
    protected boolean remove(String objectKey) {
        Query query = new Query(Criteria.where("filename").is(objectKey));
        this.template.delete(query);
        return true;
    }

    @Override
    protected boolean has(String objectKey) {
        Query query = new Query(Criteria.where("filename").is(objectKey));
        GridFSDBFile file = this.template.findOne(query);
        if (file == null) {
            return false;
        }

        // check for expiry
        Long expiry = (Long) file.get(FIELD_EXPIRY);
        if (expiry != null) {
            if (expiry.longValue() < System.currentTimeMillis()) {
                this.remove(objectKey);
                return false;
            }
        }

        return true;
    }

}