org.eclipse.mdm.nucleus/org.eclipse.mdm.businessobjects/src/main/java/org/eclipse/mdm/businessobjects/control/FileLinkActivity.java

/********************************************************************************
 * Copyright (c) 2015-2019 Contributors to the Eclipse Foundation
 *
 * See the NOTICE file(s) distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 ********************************************************************************/

package org.eclipse.mdm.businessobjects.control;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import javax.ejb.Stateless;
import javax.inject.Inject;

import org.eclipse.mdm.api.base.file.FileService;
import org.eclipse.mdm.api.base.model.Entity;
import org.eclipse.mdm.api.base.model.FileLink;
import org.eclipse.mdm.api.base.query.DataAccessException;
import org.eclipse.mdm.api.dflt.ApplicationContext;
import org.eclipse.mdm.connector.boundary.ConnectorService;

import com.google.common.io.ByteStreams;

@Stateless
public class FileLinkActivity {

	@Inject
	private ConnectorService connectorService;

	public void streamFileLink(String sourceName, Entity entity, FileLink fileLink, OutputStream outputStream) {
		try {
			ApplicationContext context = this.connectorService.getContextByName(sourceName);

			FileService fileService = context.getFileService().orElseThrow(
					() -> new MDMEntityAccessException("FileService not present in '" + sourceName + "'."));

			try (InputStream in = fileService.openStream(entity, fileLink)) {
				ByteStreams.copy(in, outputStream);
			}
		} catch (DataAccessException e) {
			throw new MDMEntityAccessException(e.getMessage(), e);
		} catch (IOException e) {
			throw new MDMEntityAccessException(e.getMessage(), e);
		}

	}
}