package com.fasterxml.jackson.jaxrs.util;

Efficient key class, used instead of using Class. The reason for having a separate key class instead of directly using Class as key is mostly to allow for redefining hashCode method -- for some strange reason, Class does not redefine Object.hashCode and thus uses identity hash, which is pretty slow. This makes key access using Class unnecessarily slow.

Note: since class is not strictly immutable, caller must know what it is doing, if changing field values.

Since:2.2
/** * Efficient key class, used instead of using <code>Class</code>. * The reason for having a separate key class instead of * directly using {@link Class} as key is mostly * to allow for redefining <code>hashCode</code> 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. *<p> * Note: since class is not strictly immutable, caller must * know what it is doing, if changing field values. * * @since 2.2 */
public final class ClassKey implements Comparable<ClassKey> { private String _className; private Class<?> _class;
Let's cache hash code straight away, since we are almost certain to need it.
/** * Let's cache hash code straight away, since we are * almost certain to need it. */
private 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 /********************************************************** */ // Just need to sort by name, ok to collide (unless used in TreeMap/Set!) @Override public int compareTo(ClassKey other) { 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; } }