QueryResultExport.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.cyclop.web.panels.queryeditor.export;

import java.io.IOException;
import java.io.OutputStream;
import java.io.Serializable;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.apache.wicket.MarkupContainer;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.util.resource.AbstractResourceStreamWriter;
import org.apache.wicket.util.resource.IResourceStream;
import org.apache.wicket.util.resource.StringResourceStream;
import org.cyclop.common.AppConfig;
import org.cyclop.model.CqlQuery;
import org.cyclop.service.exporter.CsvQueryResultExporter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/** @author Maciej Miklas */
public class QueryResultExport implements Serializable {

	private final static Logger LOG = LoggerFactory.getLogger(QueryResultExport.class);

	private final static AppConfig.QueryExport conf = AppConfig.get().queryExport;

	private final Downloader downloader;

	private final CsvQueryResultExporter exporter;

	private CqlQuery query;

	public QueryResultExport(MarkupContainer parent, CsvQueryResultExporter exporter) {
		this.exporter = exporter;
		this.downloader = new Downloader();
		parent.add(downloader);
	}

	public void initiateDownload(AjaxRequestTarget target, CqlQuery query) {
		downloader.initiateDownload(target);
		this.query = query;
	}

	private final class Downloader extends DownloadBehavior {

		@Override
		protected String getFileName() {
			SimpleDateFormat formatter = new SimpleDateFormat(conf.fileNameDate);
			String fileName = conf.fileName.replace("DATE", formatter.format(new Date()));
			LOG.debug("CSV export file name: {}", fileName);
			return fileName;
		}

		@Override
		protected IResourceStream getResourceStream() {
			if (query == null) {
				return new StringResourceStream("No Data");
			}

			return new AbstractResourceStreamWriter() {

				@Override
				public void write(OutputStream output) throws IOException {
					exporter.exportAsCsv(query, output);
				}
			};
		}
	}
}