/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
 * 
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
 * accompanied this code.  If applicable, add the following below the License
 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
 * [name of copyright owner]"
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 * 
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
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 */
 package com.sun.enterprise.deployment;

import java.lang.reflect.Field;

/** 
 * I represent a field on an ejb.
 * Either an actual field (e.g. for EJB1.1 CMP)
 * or a virtual field (e.g. for EJb2.0 CMP)
 *
 * @author Danny Coward
 */

public class FieldDescriptor extends Descriptor {

    /**
    * Constructrs an empty field descriptor 
    */
    public FieldDescriptor() {
    }    
    
    /**
    * Constructrs a field descriptor with the given name.
    */
    public FieldDescriptor(String name) {
	super(name, "no description");
    }
    
    /**
    * Constructrs a field descriptor with the given name and description.
    */
    public FieldDescriptor(String name, String description) {
	super(name, description);
    }
    
    /**
    * Constructs a field descriptor from the supplied java.lang.reflect.Field object.
    */
    
    public FieldDescriptor(Field field) {
	this(field.getName(), "no description");
    }
    
    /** Equality iff the other objects is a field descriptor with the same name.
    */
    
    public boolean equals(Object object) {
	if (object instanceof FieldDescriptor) {
	    FieldDescriptor otherFieldDescriptor = (FieldDescriptor) object;
	    return otherFieldDescriptor.getName().equals(this.getName());
	}
	return false;
    }
    
    /** My hashcode.
    */
    
    public int hashCode() {
	return this.getName().hashCode();
    }
    
    /**
    * Returns a formatted version of me as a String.
    */
    
    public void print(StringBuffer toStringBuffer) {
	toStringBuffer.append("Field: ").append(super.getName()).append("@").append(super.getDescription());
    }

    /**
     * <p>
     * Check if a field name is of an acceptable value (start with a lowercase
     * letter)
     * </p>
     * @param fieldName is the field name to test
     * @throw IllegalArgumentException if the name is unacceptable
     */
    public static void checkFieldName(String fieldName) throws IllegalArgumentException {
        
        if (fieldName == null || fieldName.length()==0) {
            throw new IllegalArgumentException("cmp-field or cmr-field name cannot be empty strings");
        }
        char firstChar = fieldName.charAt(0);
        if (!Character.isLetter(firstChar)) {
            throw new IllegalArgumentException("cmp-field or cmr-field name " + fieldName + " must begin with a letter ");
        }
        if (!Character.isLowerCase(firstChar)) {
            throw new IllegalArgumentException("cmp-field or cmr-field name " + fieldName + " must begin with a lowercase letter");
        }        
    }    
}
