LongConverter.java

/*******************************************************************************
 * Copyright (c) 2008, 2010 VMware Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   VMware Inc. - initial contribution
 *******************************************************************************/

package org.eclipse.virgo.shell.internal.converters;

import org.eclipse.virgo.shell.Converter;



/**
 * <p>
 * LongConverter is registered in the service registry to provide a conversion service 
 * from both {@link Long} and <code>long</code> to and from Strings for use by the command 
 * 
 * resolver.
 * </p>
 *
 * <strong>Concurrent Semantics</strong><br />
 *
 * LongConverter is thread safe
 *
 */
final public class LongConverter implements Converter {

    private static final String[] TYPES = new String[]{ Long.class.getName(), long.class.getName() };
    
    /**
     * Simple getter used when this class is created as a bean and placed in the service registry.
     * 
     * @return String or String[] of the types this converter can convert
     */
    public static String[] getTypes() {
        return TYPES.clone();
    }

    /** 
     * {@inheritDoc}
     */
    public Object convert(Class<?> desiredType, Object in) throws Exception {
        if(canConvert(desiredType)){
            try{
                return Long.valueOf(in.toString());
            }catch (NumberFormatException e){
                // no-op to just return null
            }
        }
        return null;
    }

    /** 
     * {@inheritDoc}
     */
    public CharSequence format(Object target, int level, Converter escape) throws Exception {
        if(canFormat(target)){
            return String.valueOf(target);
        }
        return null;
    }
    
    private boolean canConvert(Class<?> desiredType) {
        return Long.class.equals(desiredType) || long.class.equals(desiredType);
    }
    
    private boolean canFormat(Object target) {
        return target instanceof Long;
    }

}