partimpl.java

Java的面向对象数据库系统的源代码

// $Id: PartImpl.java,v 1.1 2001/12/17 17:45:08 per_nyfelt Exp $

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


public final class PartImpl extends OzoneObject implements Part, Externalizable {
    
    protected String type = "part-type9999";
    protected int x;
    protected int y;
    protected Date build;
    protected Vector to;
    protected Vector from;
    
    
    public PartImpl() {
        build = new Date();
        to = new Vector();
        from = new Vector();
    }
    
    
    public void connect( int index, Part part ) throws Exception {
        to.addElement( new Connection( part ) );
        part.backConnect( this );
    } 
    
    
    public void backConnect( Part part ) {
        if (!(part instanceof OzoneProxy)) {
            throw new RuntimeException( "backConnect(): parameter is not converted." );
        } 
        
        from.addElement( part );
    //       from.add (part);
    } 
    
    
    public void deconnect() throws Exception {
        for (Enumeration e = to.elements(); e.hasMoreElements();) {
            Connection connection = (Connection)e.nextElement();
            connection.p.deBackConnect( this );
        } 
        to.clear();
    
    //      DxIterator it = to.iterator();
    //      Connection connection;
    //      while ((connection=(Connection)it.next()) != null)
    //         connection.p.deBackConnect (this);
    } 
    
    
    public void deBackConnect( Part part ) {
        if (!from.removeElement( part )) {
            throw new RuntimeException( "deBackConnect(): cannot remove part." );
        } 
    
    //       DxIterator it = from.iterator();
    //       while (it.next() != null) {
    //          if (((OzoneProxy)part).isSame ((OzoneProxy)it.object())) {
    //             it.removeObject();
    //             break;
    //             }
    //          }
    //       throw new RuntimeException ("deBackConnect(): part not found.");
    } 
    
    
    public void set( String _type, int _x, int _y ) {
        type = _type.toString();
        x = _x;
        y = _y;
    //throw new NullPointerException();
    } 
    
    
    public void get() {
    } 
    
    
    public void traversal( int _x, int _y, int depth ) throws Exception {
        x = _x;
        y = _y;
        
        // do some db independent crunching
        //       String[] dummies = new String[1000];
        //       for (int i=0; i<1000; i++)
        //           dummies[i] = String.valueOf (i);
        
        
        if (depth > 1) {
            for (Enumeration e = to.elements(); e.hasMoreElements();) {
                Connection connection = (Connection)e.nextElement();
                connection.p.traversal( _x, _y, depth - 1 );
            } 
        } 
    } 
    
    
    public void writeExternal( ObjectOutput out ) throws IOException {
        out.writeLong( build.getTime() );
        out.writeObject( type );
        out.writeInt( x );
        out.writeInt( y );
        out.writeObject( to );
        out.writeObject( from );
    } 
    
    
    public synchronized void readExternal( ObjectInput in ) throws IOException, ClassNotFoundException {
        build = new Date( in.readLong() );
        type = (String)in.readObject();
        x = in.readInt();
        y = in.readInt();
        to = (Vector)in.readObject();
        from = (Vector)in.readObject();
    } 
    
    
    public void done() throws Exception {
    } 
    
}