Glassfish example source code file (DynamicAttributesDescriptor.java)

This example Glassfish source code file (DynamicAttributesDescriptor.java) 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.

Java - Glassfish tags/keywords

dynamicattributesdescriptor, dynamicattributesdescriptor, hashtable, io, iterator, map, map, object, object, observable, property, serializable, string, string, stringbuffer, util

The Glassfish DynamicAttributesDescriptor.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. 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_1_1.html
 * or packager/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 packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * 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
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.enterprise.deployment;

import java.io.Serializable;
import java.util.*;

/**
 * This class is a value holder for dynamic attributes. Dynamic attributes 
 * can be added, queried and removed from this value holder. Attributes are 
 * identified by a string key.
 *
 * @author Jerome Dochez
 */
public class DynamicAttributesDescriptor extends Observable implements Serializable {
    
    private Map dynamicAttributes;
    
    /**
    * Direct acess to the dynamic attributes repository
    * @return the Map of dynamic attributes
    */

    public Map getExtraAttributes() {
	if (dynamicAttributes == null) {
	    dynamicAttributes = new Hashtable();
	}
	return dynamicAttributes;
    }
    
    /**
     * Add a new dynamic attribte
     * @param name the attribute name
     * @param value the attribute value
     */
    public void addExtraAttribute(String name, Object value) {
        if (value==null) {
            return;
        }
	if (dynamicAttributes == null) {
	    dynamicAttributes = new Hashtable();
	}
        dynamicAttributes.put(name, value);
        changed();
    }
    
    /**
     * Obtain a dynamic attribute from the repository
     * @param name the attribute name
     * @return the attribute value of null of non existent
     */
    public Object getExtraAttribute(String name) {
        if (dynamicAttributes == null) {
            return null;
        }
        return dynamicAttributes.get(name);
    }
    
    /**
     * Removes a dynamic attribute from the repository
     * @param name the attribute name
     */
    public void removeExtraAttribute(String name) {
        if (dynamicAttributes == null) {
            return;
        } 
        dynamicAttributes.remove(name);
        changed();
    }
    
    /**
     * @return a meaningfull string about ourself
     * This method is invoked by toString() method.  This method can be overwritten by any descriptor which inherits this class
     * to self describe. This pattern is adopted to imporve the performance of S1AS 8.0 which avoids creation of several String objects
     * in toString() method. 
     * When toString() method is called on a Descriptor object, the toString method of this class is called.  
     * The toString method of this class invokes print(StringBuffer) method.  If the Descriptor object overrides print method, its method
     * will be invoked. 
     * For better performance, care should be taken to use print method on all descriptors instead of printing object itself (which calls to toString).
     * For example 
     * Iterator itr = getDeploymentExtensions();
            if (itr!=null && itr.hasNext()) {
               do {
                   sb.append("\n Deployment Extension : ").append(itr.next());
               } while (itr.hasNext());
           }


            should probably read as below.

           Iterator itr = getDeploymentExtensions();
           if (itr!=null && itr.hasNext()) {
               do {
                   sb.append("\n Deployment Extension : ");
            ((Descriptor) itr.next()).print(sb);
               } while (itr.hasNext());
           } 
     */ 
    public void print(StringBuffer toStringBuffer) {
        if (dynamicAttributes==null) {
            toStringBuffer.append("<== No attribute ==>");
        }  else {
           toStringBuffer.append("==>Dynamic Attribute");
           Set keys = dynamicAttributes.keySet();
           for (Iterator itr = keys.iterator();itr.hasNext();) {
               String keyName = (String) itr.next();
               Object o = getExtraAttribute(keyName);
	       if (o instanceof Object[]) {
		   Object[] objects = (Object[]) o;
		   for (int i=0;i<objects.length;i++) {
		       toStringBuffer.append("\n Indexed prop name ").append(keyName).append("[").append(i).append("] = ");
                       if(objects[i] instanceof DynamicAttributesDescriptor)
                            ((DynamicAttributesDescriptor)objects[i]).print(toStringBuffer);
                       else
                            toStringBuffer.append(objects[i]);
		   }
	       } else {
		   toStringBuffer.append("\n  Property name = ").append(keyName).append(" value = ");
                   if(o instanceof DynamicAttributesDescriptor)
                            ((DynamicAttributesDescriptor)o).print(toStringBuffer);
                       else
                            toStringBuffer.append(o);
               }
           }
	   toStringBuffer.append("\n<==End");
           return ;
        }
    }
    /**
     * @return a meaningfull string about ourself
     * No Descriptor class which inherits this class should override this method.  Rather print() method which is defined in this class
     * should be overridden to describe itself. Refer to the comments on print() method for more details.
     * This method is optimized for persformance reasons.
     */ 
    public String toString() {
        StringBuffer toStringBuf = new StringBuffer();
        this.print(toStringBuf);
        return toStringBuf.toString();
    }
    
    /**
     * notify our observers we have changed
     */
    private void changed() {
        setChanged();
        notifyObservers();
    }
}