deletereactor.java

简单的会议议程系统,展示了Command 模式的应用

/*
 * @(#)DeleteReactor.java        2006/11/13
 *
 * Copyright (c) ZhiYang.
 * All rights reserved.
*/

package his; // HIS: Human Interactive Service
import agenda.*;

import java.text.*;

/**
 * 会议反应器：删除用户指定的会议记录
 * @version 1.0
 * @author 杨智 (MSE2006B-06250145)
 *
 */

public class DeleteReactor extends MeetingReactor  {
	
	DeleteReactor(){
		super("delete");
	}
	public String name;

	/**
	 * do query command
	 * @params Object[]
	 * ******* String username;
	 * ******* String password;
	 * ******* String title;
	*/
	public boolean doit ( Object[] params, UIMessager msgr ) {
		try {
			User aUser = new User( (String)params[0],(String)params[1] );
			String title = (String)params[2];
			if( !umgr.validateUser( aUser) ) {
				msgr.println("invalid username or password!");
				return false;				
			}
			if( !mmgr.deleteMeeting ( title ) ) {
				msgr.println("meeting[" + title + "] not found");
				return false;									
			}
			msgr.println("meeting[" + title + "] deleted");
			return true;				
		}
		catch ( Exception e ) {
		}
		return false;
	}
	
	/*
	 * @see doit
	*/
	public Object[] parseParameters( String[] params ){
		if( null==params || params.length!=3 )
			return null;
		Object[] ret = new Object[3];
		ret[0] = new String ( params[0] );
		ret[1] = new String ( params[1] );
		ret[2] = new String ( params[2] );
		return ret;
	}
	
	/*
	 * print Usage
	*/
	public void printUsage( UIMessager msger ) {
		msger.println("Usage: ");
		msger.println("\tdelete userName password meeting_title");
		msger.println("Ex:\tdelete su2 su2pwd mt2");
	}
}