propertyconfigurablefactory.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Core License version 1 published by ozone-db.org.
//
// Copyright (C) 2003-@year@, Leo Mekenkamp. All rights reserved.
//
// $Id: PropertyConfigurableFactory.java,v 1.1 2004/01/01 20:29:29 leomekenkamp Exp $

package org.ozoneDB.core.storage;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.Properties;
import org.ozoneDB.core.ConfigurationException;

/**
 *
 * @author <a href="mailto:leoATmekenkampD0Tcom">Leo Mekenkamp (mind the anti sp@m)</a>
 * @version $Id: PropertyConfigurableFactory.java,v 1.1 2004/01/01 20:29:29 leomekenkamp Exp $
 */
public class PropertyConfigurableFactory {
    
    private PropertyConfigurableFactory() {
    }

    public static PropertyConfigurable create(Class assignableFrom, Properties properties, String propertyName) {
        String className = properties.getProperty(propertyName);
        if (className == null) {
            throw new ConfigurationException("could not find property: '" + propertyName + "'");
        }
        try {
            Class classType = Class.forName(className);
            if (!PropertyConfigurable.class.isAssignableFrom(classType)) {
                throw new ConfigurationException(className + " should implement " + PropertyConfigurable.class);
            }
            if (!assignableFrom.isAssignableFrom(classType)) {
                throw new ConfigurationException(className + " should implement " + assignableFrom);
            }
            Constructor constructor = classType.getConstructor(new Class[] {Properties.class, String.class});
            PropertyConfigurable result = (PropertyConfigurable) constructor.newInstance(new Object[] {properties, propertyName});
            return result;
        } catch (ClassNotFoundException e) {
            throw new ConfigurationException(e);
        } catch (NoSuchMethodException e) {
            throw new ConfigurationException(className + " does not follow PropertyConfigurable constructor contract", e);
        } catch (InstantiationException e) {
            throw new ConfigurationException(e);
        } catch (IllegalAccessException e) {
            throw new ConfigurationException(e);
        } catch (InvocationTargetException e) {
            throw new ConfigurationException(e);
        }
    }
    
}