D-Net

package eu.dnetlib.data.objectstore.s3;

import java.io.*;

import java.net.URLEncoder;

import java.nio.file.Files;

import java.nio.file.Path;

import javax.servlet.http.HttpServletResponse;

import com.amazonaws.ClientConfiguration;

import com.amazonaws.Protocol;

import com.amazonaws.auth.AWSCredentials;

import com.amazonaws.auth.AWSStaticCredentialsProvider;

import com.amazonaws.auth.BasicAWSCredentials;

import com.amazonaws.client.builder.AwsClientBuilder;

import com.amazonaws.services.s3.AmazonS3;

import com.amazonaws.services.s3.AmazonS3ClientBuilder;

import com.amazonaws.services.s3.model.S3Object;

import eu.dnetlib.data.objectstore.rmi.ObjectStoreServiceException;

import eu.dnetlib.miscutils.datetime.HumanTime;

import org.apache.commons.io.IOUtils;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

/**

 * The Class ModularObjectStoreRESTService implement the controller REST of the object Store.

 */

@Controller

public class ModularObjectStoreRESTService {

    private static final Log log = LogFactory.getLog(ModularObjectStoreRESTService.class); // NOPMD by marko on 11/24/08 5:02 PM

    @Value("${dnet.objectStore.s3.accessKey}")

    private String accessKey;

    @Value("${dnet.objectStore.s3.secretKey}")

    private String secretKey;

    @Value("${dnet.objectStore.s3.endPoint}")

    private String s3EndPoint;

    @Value("${dnet.objectStore.s3.objectStoreBucket}")

    private String objectStoreBucket;

    private AmazonS3 client;

    private static final String S3_REGION = "eu-west-3";

    private AmazonS3 initializeClient() throws ObjectStoreServiceException {

        try {

            final AWSCredentials credentials = new BasicAWSCredentials(this.accessKey, this.secretKey);

            final ClientConfiguration cfg = new ClientConfiguration().withProtocol(Protocol.HTTPS);

            final AmazonS3 s3 = AmazonS3ClientBuilder.standard().withCredentials(new AWSStaticCredentialsProvider(credentials))

                    .withClientConfiguration(cfg)

                    .withEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration(this.s3EndPoint, S3_REGION))

                    .build();

            if (s3 == null)

                throw new ObjectStoreServiceException("Cannot initialize s3 client because is NULL");

            return s3;

        } catch (Throwable e) {

            log.error("An Error happen on initialize client ", e);

            throw new ObjectStoreServiceException("Cannot initialize s3 client", e);

        }

    }

    public static String retrieveURL(final String baseURI, final String basePath, final String objectStoreId, final String objectId)

            throws UnsupportedEncodingException {

        final StringBuilder sb = new StringBuilder(baseURI)

                .append("?objectStore=" + encode(objectStoreId))

                .append("&objectId=" + encode(objectId))

                .append("&basePath=" + encode(basePath));

        return sb.toString();

    }

    private static String encode(final String s) throws UnsupportedEncodingException {

        return URLEncoder.encode(s, "UTF-8");

    }

    /**

     *

     * @param res

     * @param objectStoreId

     * @param objectId

     * @throws IOException

     * @throws ObjectStoreServiceException

     */

    @RequestMapping(value = "/**/objectStore/retrieve.do")

    public void retrieve(final HttpServletResponse res,

                         @RequestParam(value = "objectStore", required = true) final String objectStoreId,

                         @RequestParam(value = "objectId", required = true) final String objectId) throws IOException, ObjectStoreServiceException {

        final long start = System.currentTimeMillis();

        if (client == null)

            client = initializeClient();

        final S3Object object = this.client.getObject(objectStoreBucket, objectStoreId + "/" + objectId);

        if (object == null) {

            final String msg = String.format("Object with identifier: %s not found the in %s", objectId, objectStoreId);

            res.sendError(HttpServletResponse.SC_NOT_FOUND, msg);

            log.warn(msg);

        } else {

            try ( final InputStream is =  object.getObjectContent()) {

                res.setHeader("Content-Length", String.valueOf(object.getObjectMetadata().getContentLength()));

                IOUtils.copyLarge(is, res.getOutputStream());

                if (log.isDebugEnabled()) {

                    log.debug(String.format("retrive.do completed in %s, objId: %s", HumanTime.exactly(System.currentTimeMillis() - start), objectId));

                }

            } catch (IOException e) {

                final String msg = "unable to close input Stream";

                res.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, msg);

                log.error(msg, e);

            }

        }

    }

}