dbcommand.java

用Java写的面相对象的数据库管理系统

// You can redistribute this software and/or modify it under the terms of
// the Ozone Core License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-2000 by SMB GmbH. All rights reserved.
//
// $Id: DbCommand.java,v 1.19 2000/10/28 16:55:17 daniela Exp $

package org.ozoneDB.core.DbRemote;

import java.io.*;
import org.ozoneDB.DxLib.DxObject;
import org.ozoneDB.core.*;
import org.ozoneDB.util.*;


/**
 * This is the base class for command that can be send to an ozone server.
 * 
 * 
 * @author <a href="http://www.softwarebuero.de/">SMB</a>
 * @version $Revision: 1.19 $Date: 2000/10/28 16:55:17 $
 */
public abstract class DbCommand extends DxObject {
    
    /**
     * Environment of this object. Will be set by InvokeServer.
     */
    public transient Env env;
    
    /**
     * Result of the command. This will only be used on the server side.
     */
    public transient Object result;
    
    
    public DbCommand() {
    }
    
    
    /**
     * Perform whatever has to be done for this command. This method is called
     * within a transaction, within a thread. The result of the command goes in
     * the result member.
     */
    public abstract void perform( Transaction ta ) throws Exception;
    
    
    public String toString() {
        return "[" + LogWriter.rawClassName( this ) + "]";
    } 
    
}