dbnextid.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: DbNextID.java,v 1.3 2000/10/28 16:55:17 daniela Exp $

package org.ozoneDB.core.DbRemote;

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


/**
 * @author <a href="http://www.softwarebuero.de/">SMB</a>
 * @version $Revision: 1.3 $Date: 2000/10/28 16:55:17 $
 */
public final class DbNextID extends DbCommand {
    
    private long range;
    
    
    public DbNextID( long _range ) {
        range = _range;
    }
    
    
    public void perform( Transaction ta ) throws Exception {
        // env.logWriter.newEntry (this, "DbCreateObj.perform()...", LogWriter.DEBUG);
        
        long id = env.nextID( range );
        result = new ObjectID( id );
    } 
    
    
    public void writeExternal( ObjectOutput out ) throws IOException {
        out.writeLong( range );
    } 
    
    
    public synchronized void readExternal( ObjectInput in ) throws IOException, ClassNotFoundException {
        range = in.readLong();
    } 
    
}