RrdtoolDataSource.java

/*******************************************************************************
 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 *
 * OpenNMS(R) is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenNMS(R).  If not, see:
 *      http://www.gnu.org/licenses/
 *
 * For more information contact:
 *     OpenNMS(R) Licensing <license@opennms.org>
 *     http://www.opennms.org/
 *     http://www.opennms.com/
 *******************************************************************************/

package org.opennms.netmgt.jasper.rrdtool;

import java.util.Date;

import net.sf.jasperreports.engine.JRDataSource;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRField;

public class RrdtoolDataSource implements JRDataSource {

	private int m_currentRow = -1;
	private Xport m_data;

	public RrdtoolDataSource(Xport data) {
		this.m_data = data;
	}

	public Object getFieldValue(JRField field) throws JRException {
		if ("Timestamp".equalsIgnoreCase(getColumnName(field))) {
			long ts = new Long(m_data.getData().getRow(m_currentRow).getT().getContent()) * 1000l;
			return new Date(ts);
		}
		int index = getColumnIndex(field);
		return new Double(m_data.getData().getRow(m_currentRow).getV(index).getContent());
	}

	private String getColumnName(JRField field) {
		return field.getDescription() == null || field.getDescription().trim().equals("")
		        ? field.getName() : field.getDescription();
	}

	public boolean next() throws JRException {
		m_currentRow++;
		return m_data == null || m_data.getData() == null ? false : m_currentRow < m_data.getData().getRowCount();
	}

	private int getColumnIndex(JRField field) {
		String column = getColumnName(field);
		int i=0;
		for (Entry legend : m_data.getMeta().getLegend().getEntryCollection()) {
			if (legend.getContent().equals(column))
				return i;
			i++;
		}
		return -1;
	}

}