abstractmodelobject.java

来自「纯java操作系统jnode,安装简单和操作简单的个人使用的Java操作系统」· Java 代码 · 共 61 行

/*
 * $Id: AbstractModelObject.java,v 1.3 2004/01/02 08:41:56 epr Exp $
 */
package org.jnode.plugin.model;

import nanoxml.XMLElement;

import org.jnode.plugin.PluginException;
import org.jnode.vm.VmSystemObject;

/**
 * @author epr
 */
public abstract class AbstractModelObject extends VmSystemObject {

	/**
	 * Utility method to get an attribute from and element and test for its presence if it is required.
	 * 
	 * @param e
	 * @param name
	 * @param required
	 * @return The attribute
	 * @throws PluginException
	 *             required is true, but the attribute was not found
	 */
	protected final String getAttribute(XMLElement e, String name, boolean required) throws PluginException {
		final String v = e.getStringAttribute(name);
		if (required) {
			if (v == null) {
				throw new PluginException("Required attribute " + name + " in element " + e.getName() + " not found");
			}
		}
		return v;
	}

	/**
	 * Utility method to get an attribute from and element and test for its presence if it is required.
	 * 
	 * @param e
	 * @param name
	 * @param defValue
	 * @return The attribute
	 * @throws PluginException
	 *             required is true, but the attribute was not found
	 */
	protected final boolean getBooleanAttribute(XMLElement e, String name, boolean defValue) throws PluginException {
		final String v = getAttribute(e, name, false);
		if (v == null) {
			return defValue;
		}
		return v.equalsIgnoreCase("true") || v.equals("1") || v.equalsIgnoreCase("yes") || v.equalsIgnoreCase("on");
	}

	/**
	 * Resolve all references to (elements of) other plugin descriptors
	 * 
	 * @throws PluginException
	 */
	protected abstract void resolve() throws PluginException;
}