symbol.java

JStock是一个免费股市软件

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Copyright (C) 2008 Yan Cheng Cheok <[e-mail]>
 */

package org.yccheok.jstock.engine;

/**
 *
 * @author yccheok
 */
public class Symbol {
    private Symbol(String symbol) {
        this.symbol = symbol;
    }
    
    public static Symbol newInstance(String symbol) {
        if(symbol == null) {
            throw new java.lang.IllegalArgumentException("symbol cannot be null");
        }
        
        return new Symbol(symbol);
    }

    @Override
    public int hashCode() {
        int result = 37;
        result = result * symbol.hashCode();
        
        return result;
    }
    
    @Override
    public boolean equals(Object o) {
        if(!(o instanceof Symbol))
            return false;
        
        return this.symbol.equals(((Symbol)o).symbol);
    }
    
    @Override
    public String toString() {
        return symbol;
    }
    
    private String symbol;
}