ConfigBase.java

/*******************************************************************************
 *
 *	Copyright (c) 2009 Fujitsu Services Ltd.
 *
 *	Author: Nick Battle
 *
 *	This file is part of VDMJ.
 *
 *	VDMJ 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.
 *
 *	VDMJ 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 VDMJ.  If not, see <http://www.gnu.org/licenses/>.
 *
 ******************************************************************************/

package org.overture.util;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.util.Properties;

public class ConfigBase
{
	private static Properties props = new Properties();

	public static void init(String resource, Class<?> target) throws Exception
	{
		InputStream fis = null;
		String propertyFile = resource;

		try
		{
			try
			{
				fis = ConfigBase.class.getResourceAsStream("/" + resource);

				if (fis == null)
				{
					// properties file is not on the classpath
					return;
				}

				props.load(fis);
			} catch (Exception ex)
			{
				throw new Exception(propertyFile + ": " + ex.getMessage());
			}

			String name = "?";
			String value = "?";

			try
			{
				for (Field f : target.getFields())
				{
					name = f.getName();
					Class<?> type = f.getType();
					value = props.getProperty(name.replace('_', '.'));

					if (value != null)
					{
						if (type == Integer.TYPE)
						{
							f.setInt(target, Integer.parseInt(value));
						} else if (type == Boolean.TYPE)
						{
							f.setBoolean(target, Boolean.parseBoolean(value));
						} else if (type == String.class)
						{
							f.set(target, value);
						} else
						{
							throw new Exception("Cannot process " + name
									+ ", Java type " + type + " unsupported");
						}
					}
				}
			} catch (Exception ex)
			{
				throw new Exception(propertyFile + ": (" + name + " = " + value
						+ ") " + ex.getMessage());
			}
		} finally
		{
			if (fis != null)
			{
				try
				{
					fis.close();
				} catch (IOException e)
				{
					// so?
				}
			}
		}
	}

	public static String getProperty(String key, String def)
	{
		return props.getProperty(key, def);
	}
}