commandfactory.java

来自「电信的网厅的整站代码」· Java 代码 · 共 106 行

package com.doone.wskfmgr.common.command;

import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import com.doone.fj1w.common.PropertiesExtra;
import com.doone.util.FileLogger;

/**
 * A singleton class that creates commands using the command mapping property
 * file.
 * 
 * @pattern FrontController (role=commandFactoryClass)
 * 
 * @generatedBy CodePro at 07-1-30 H9:22
 * 
 * @author wushaol
 * 
 * @version $Revision$
 */
class CommandFactory {

	/**
	 * The name of the property file mapping command names to classes.
	 */
	private static final java.lang.String COMMAND_MAPPING_PROPERTY_FILE  = "commandMapping.properties";

	/**
	 * Mapping of command name to command class.
	 */
	private static Map commands;

	/**
	 * Construct an instance.
	 */
	private CommandFactory() {
	}

	/**
	 * Create the map of command names to command classes.
	 */
	private static void createCommandMap() {
		Map commandMap = new HashMap();
		try {
			PropertiesExtra extra = new PropertiesExtra(COMMAND_MAPPING_PROPERTY_FILE);
			Properties properties = extra.getProperties();

			for (Enumeration e = properties.keys(); e.hasMoreElements();) {
				String action = (String) e.nextElement();
				Class newCommandClass = Class.forName(properties
						.getProperty(action));
				commandMap.put(action, newCommandClass);
			}
		} catch (Exception e) {
			FileLogger.getLogger().warn(
					"初始化命今模式失败,命今工厂将无法工作,请查询原因: " + e.getMessage(), e);
		}
		setCommands(commandMap);
	}

	/**
	 * Get the map from command names to command classes.
	 * 
	 * @return the map from command names to command classes
	 */
	private synchronized static Map getCommands() {
		if (commands == null) {
			createCommandMap();
		}
		return commands;
	}

	/**
	 * Set the map from command names to command classes.
	 * 
	 * @return commandMap the new map from command names to command classes
	 */
	private static void setCommands(Map commandMap) {
		commands = commandMap;
	}

	/**
	 * Create a RegistCommandInterface instance for the specified action or
	 * command.
	 * 
	 * @param action
	 *            the name of the command
	 * 
	 * @return RegistCommandInterface or <code>null</code> if the command
	 *         could not be created
	 */
	public static CommandInterface getCommand(String action) {
		Class newCommandClass = (Class) getCommands().get(action);
		CommandInterface newCommand = null;
		try {
			newCommand = (CommandInterface) newCommandClass.newInstance();
		} catch (Exception e) {
			FileLogger.getLogger().warn(
					"生成" + action + "命今操作失败: " + e.getMessage(), e);
		}
		return newCommand;
	}
}