SwiftMigrationDAO.java

package eu.europeana.cloud.swiftmigrate;

import eu.europeana.cloud.service.mcs.exception.FileAlreadyExistsException;
import eu.europeana.cloud.service.mcs.exception.FileNotExistsException;
import eu.europeana.cloud.service.mcs.persistent.swift.SimpleSwiftConnectionProvider;
import java.util.HashSet;
import java.util.Set;
import org.jclouds.blobstore.BlobStore;
import org.jclouds.blobstore.domain.Blob;
import org.jclouds.blobstore.domain.PageSet;
import org.jclouds.blobstore.domain.StorageMetadata;
import org.jclouds.blobstore.options.ListContainerOptions;

/**
 * Class copy files from source container to target container.
 * 
 */
public class SwiftMigrationDAO {

    final SimpleSwiftConnectionProvider sourceProvider;
    final SimpleSwiftConnectionProvider targetProvider;


    public SwiftMigrationDAO(final SimpleSwiftConnectionProvider sourceConnectionProvider,
            final SimpleSwiftConnectionProvider targetConnectionProvider) {
        this.sourceProvider = sourceConnectionProvider;
        this.targetProvider = targetConnectionProvider;
    }


    /**
     * Metod copy single file from source container to target container.
     * 
     * @param sourceObjectId
     *            source object name
     * @param trgObjectId
     *            target object name
     * @throws FileNotExistsException
     * @throws FileAlreadyExistsException
     */
    public void copyFile(final String sourceObjectId, final String trgObjectId)
            throws FileNotExistsException, FileAlreadyExistsException {
        final BlobStore blobStore = sourceProvider.getBlobStore();
        if (!blobStore.blobExists(sourceProvider.getContainer(), sourceObjectId)) {
            throw new FileNotExistsException(String.format("File %s not exists", sourceObjectId));
        }
        if (blobStore.blobExists(targetProvider.getContainer(), trgObjectId)) {
            throw new FileAlreadyExistsException(String.format("Target file %s already exists", trgObjectId));
        }
        final String container = targetProvider.getContainer();
        final Blob blob = blobStore.getBlob(sourceProvider.getContainer(), sourceObjectId);
        final Blob newBlob = blobStore.blobBuilder(trgObjectId).name(trgObjectId).payload(blob.getPayload()).build();
        blobStore.putBlob(container, newBlob);
    }


    /**
     * Method retrives list of files from source container.
     * 
     * @return list of files
     */
    public Set<String> getFilesList() {
        final BlobStore blobStore = sourceProvider.getBlobStore();
        final String container = sourceProvider.getContainer();
        final Set<String> names = new HashSet<String>();
        PageSet<? extends StorageMetadata> ObjectList = blobStore.list(container);
        String marker = null;
        for (int i = 0; i < 500; i++) {

            for (StorageMetadata files : ObjectList) {
                names.add(files.getName());
            }
            marker = ObjectList.getNextMarker();
            if (marker == null) {
                break;
            }
            ObjectList = blobStore.list(container, ListContainerOptions.Builder.afterMarker(marker));
        }
        return names;
    }

}