org.codehaus.jackson.map.ser.ClassKey Maven / Gradle / Ivy
package org.codehaus.jackson.map.ser;
/**
* Key class, used as an efficient and accurate key
* for locating per-class values, such as
* {@link org.codehaus.jackson.map.JsonSerializer}s.
*
* 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();
}
protected 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
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;
/* 09-Dec-2008, tatu: Hmmh. 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; }
}