/*
* Copyright (c) 2000, 2005, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.beans;
import java.util.HashMap;
import java.util.IdentityHashMap;
import java.util.Map;
import static java.util.Locale.ENGLISH;
/**
* A utility class which generates unique names for object instances.
* The name will be a concatenation of the unqualified class name
* and an instance number.
* <p>
* For example, if the first object instance javax.swing.JButton
* is passed into <code>instanceName</code> then the returned
* string identifier will be "JButton0".
*
* @author Philip Milne
*/
class NameGenerator {
private Map valueToName;
private Map nameToCount;
public NameGenerator() {
valueToName = new IdentityHashMap();
nameToCount = new HashMap();
}
/**
* Clears the name cache. Should be called to near the end of
* the encoding cycle.
*/
public void clear() {
valueToName.clear();
nameToCount.clear();
}
/**
* Returns the root name of the class.
*/
public static String unqualifiedClassName(Class type) {
if (type.isArray()) {
return unqualifiedClassName(type.getComponentType())+"Array";
}
String name = type.getName();
return name.substring(name.lastIndexOf('.')+1);
}
/**
* Returns a String which capitalizes the first letter of the string.
*/
public static String capitalize(String name) {
if (name == null || name.length() == 0) {
return name;
}
return name.substring(0, 1).toUpperCase(ENGLISH) + name.substring(1);
}
/**
* Returns a unique string which identifies the object instance.
* Invocations are cached so that if an object has been previously
* passed into this method then the same identifier is returned.
*
* @param instance object used to generate string
* @return a unique string representing the object
*/
public String instanceName(Object instance) {
if (instance == null) {
return "null";
}
if (instance instanceof Class) {
return unqualifiedClassName((Class)instance);
}
else {
String result = (String)valueToName.get(instance);
if (result != null) {
return result;
}
Class type = instance.getClass();
String className = unqualifiedClassName(type);
Object size = nameToCount.get(className);
int instanceNumber = (size == null) ? 0 : ((Integer)size).intValue() + 1;
nameToCount.put(className, new Integer(instanceNumber));
result = className + instanceNumber;
valueToName.put(instance, result);
return result;
}
}
}