objectid.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: ObjectID.java,v 1.17 2000/10/28 16:55:16 daniela Exp $

package org.ozoneDB.core;

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


public class ObjectID extends DxObject implements Externalizable {
    
    final static long serialVersionUID = 2;
    final static byte subSerialVersionUID = 1;
    
    private long value = -1;
    
    
    public ObjectID() {
    }
    
    
    public ObjectID( long v ) {
        value = v;
    }
    
    
    public long value() {
        return value;
    } 
    
    
    public final int hashCode() {
        //wenn diese 32 bits keinen unterschied mehr bringen,
        //wird mit equals() weiter verglichen
        return (int)value;
    } 
    
    
    public final boolean equals( Object obj ) {
        if (obj instanceof ObjectID) {
            return value == ((ObjectID)obj).value;
        } 
        return false;
    } 
    
    
    public final boolean isLess( DxCompatible obj ) {
        if (obj instanceof ObjectID) {
            return value < ((ObjectID)obj).value;
        } 
        return false;
    } 
    
    
    public Object clone() {
        return new ObjectID( value );
    } 
    
    
    public void writeExternal( ObjectOutput out ) throws IOException {
        // env.logWriter.newEntry ("write: " + getClass().toString() + " " + value, LogWriter.DEBUG);
        out.writeByte( subSerialVersionUID );
        out.writeLong( value );
    } 
    
    
    public void readExternal( ObjectInput in ) throws IOException, ClassNotFoundException {
        byte streamVersionUID = in.readByte();
        value = in.readLong();
    // env.logWriter.newEntry ("read: " + getClass().toString() + " " + value, LogWriter.DEBUG);
    } 
    
    
    /**
     * The value of the ObjectID as String. DO not change this, the name
     * of the cluster files depend on it.
     */
    public String toString() {
        return String.valueOf( value );
    } 
}