org.apache.wink.common.internal.type.ClassKey Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.wink.common.internal.type;
/**
* Key class, used as an efficient and accurate key
* for locating per-class values
*
* The reason for having a separate key class instead of
* directly using {@link Class} as key is mostly
* to allow for redefining hashCode method --
* for some strange reason, {@link Class} does not
* redefine {@link Object#hashCode} and thus uses identity
* hash, which is pretty slow. This makes key access using
* {@link Class} unnecessarily slow.
*
* Note: since class is not strictly immutable, caller must
* know what it is doing, if changing field values.
*/
public final class ClassKey implements Comparable {
String _className;
Class _class;
/**
* Let's cache hash code straight away, since we are
* almost certain to need it.
*/
int _hashCode;
public ClassKey() {
_class = null;
_className = null;
_hashCode = 0;
}
public ClassKey(Class clz) {
_class = clz;
_className = clz.getName();
_hashCode = _className.hashCode();
}
public void reset(Class clz) {
_class = clz;
_className = clz.getName();
_hashCode = _className.hashCode();
}
/*
/**********************************************************
/* Comparable
/**********************************************************
*/
public int compareTo(ClassKey other) {
// Just need to sort by name, ok to collide (unless used in TreeMap/Set!)
return _className.compareTo(other._className);
}
/*
/**********************************************************
/* Standard methods
/**********************************************************
*/
@Override
public boolean equals(Object o) {
if (o == this)
return true;
if (o == null)
return false;
if (o.getClass() != getClass())
return false;
ClassKey other = (ClassKey)o;
/* Is it possible to have different Class object for same name + class loader combo?
* Let's assume answer is no: if this is wrong, will need to uncomment following functionality
*/
/*
return (other._className.equals(_className))
&& (other._class.getClassLoader() == _class.getClassLoader());
*/
return other._class == _class;
}
@Override
public int hashCode() {
return _hashCode;
}
@Override
public String toString() {
return _className;
}
}