alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

/*
 *                 Sun Public License Notice
 * 
 * The contents of this file are subject to the Sun Public License
 * Version 1.0 (the "License"). You may not use this file except in
 * compliance with the License. A copy of the License is available at
 * http://www.sun.com/
 * 
 * The Original Code is NetBeans. The Initial Developer of the Original
 * Code is Sun Microsystems, Inc. Portions Copyright 1997-2001 Sun
 * Microsystems, Inc. All Rights Reserved.
 */
package org.netbeans.mdr.persistence.btreeimpl.btreestorage;

import java.io.*;
import java.text.*;
import java.util.*;
import org.netbeans.mdr.persistence.*;
import org.netbeans.mdr.persistence.btreeimpl.btreeindex.*;

/**
* This is an index from names (Strings) to Integer.  Its primary use is to 
* store the codes for classes stored in the repository.
*/
public class CounterIndex extends NameIndex {

    /* next integer to be assigned */
    int nextInt = 0;

    /** Create a new CounterIndex  */
    public CounterIndex() {
    }

    /** get an integer by its name.  If none exists, throw an exception
    * @param name the name associated with the integer
    */
    public synchronized int get(String name) throws StorageException  {
    	return ((Integer)getObj(name)).intValue();
    }

    /** get an integer by its name.  If none exists, return null
    * @param name the name associated with the integer
    */
    public synchronized Integer getIf(String name) throws StorageException  {
    	return (Integer)getObjIf(name);
    }

    /**
    * Add a name-MOFID pair to the MofidIndex.  If one already existed,
    * throw an exception.
    * @param name name of object to add to index
    * @param id MOFID of object to add
    */
    public synchronized int add(String name) throws StorageException {
	int i = nextInt++;
    	addObj(name, new Integer(i));
	return i;
    }

    /* write to a DataOutputStream
    */
    public synchronized void write(DataOutputStream dstrm) throws StorageException{
	super.write(dstrm);
	try {
	    dstrm.writeInt(nextInt);
	}
	catch (IOException ex) {
	    throw new StorageIOException(ex);
	}
    }

    /** read from a DataOutputStream
    */
    public synchronized void read(DataInputStream dstrm) throws StorageException{
	super.read(dstrm);
	try {
	    nextInt = dstrm.readInt();
	}
	catch (IOException ex) {
	    throw new StorageIOException(ex);
	}
    }

    /**
    * write object to stream.  Used by serialization.
    * @param obj object to write
    * @param strm stream to write it to
    */
    protected void writeObjectToStream(Object obj, DataOutputStream strm) 
    	throws StorageException {
	try {
	    strm.writeInt(((Integer)obj).intValue());
	}
	catch (IOException ex) {
	    throw new StorageIOException(ex);
	}
    }

    /**
    * read object from stream.  Used by deserialization.
    * @param strm stream to read from
    * @return obj object read
    */
    protected Object readObjectFromStream(DataInputStream strm) 
    	throws StorageException {
	try {
	    return new Integer(strm.readInt());
	}
	catch (IOException ex) {
	    throw new StorageIOException(ex);
	}
	
    }
}



... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.