content: /*
   * LabelKey.java April 2012
   *
   * Copyright (C) 2012, Niall Gallagher <niallg@users.sf.net>
   *
   * Licensed 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 com.aliyun.odps.simpleframework.xml.core;
  
  import java.lang.annotation.Annotation;
  
  /**
   * The <code>LabelKey</code> object is used to create a key that will
   * uniquely identify an annotated method within a class. Creation of 
   * a key in this way enables annotated methods and fields to be cached
   * and looked up using a key.
   * 
   * @author Niall Gallagher
   */
  class LabelKey {
  
     /**
      * This is the annotation type that this is represented in the key.
      */
     private final Class label;
     
     /**
      * This is the declaring class where the method or field is defined.
      */
     private final Class owner;
     
     /**
      * This is the type that is represented by the annotated contact.
      */
     private final Class type;
     
     /**
      * This is the name of the field or method that is represented.
      */
     private final String name;
     
     /**
      * Constructor for the <code>LabelKey</code> object. This is used
      * to create an object using the contact and associated annotation
      * that can uniquely identity the label.
      * 
      * @param contact this is the contact that has been annotated
      * @param label this is the primary annotation associated with this
      */
     public LabelKey(Contact contact, Annotation label) {
        this.owner = contact.getDeclaringClass();
        this.label = label.annotationType();
        this.name = contact.getName();
        this.type = contact.getType();    
     }
     
     /**
      * This returns the unique has code used for this key. The hash 
      * code is created by combining the hash code of the method or field
      * name with the hash code of the declaring class.
      * 
      * @return this returns the hash code associated with this key
      */
     public int hashCode() {
        return name.hashCode() ^ owner.hashCode();
     }
     
     /**
      * This is used to determine if two keys are the same. Ultimately 
      * two keys are equal if they represent the same contact and
      * annotation from that contact. If everything is equal by
      * identity then this will be true.
      * 
      * @param value this is the value to compare to this key
      * 
      * @return this returns true if both keys have the same data
      */
     public boolean equals(Object value) {
        if(value instanceof LabelKey) {
           return equals((LabelKey)value);
        }
        return false;
     }
     
     /**
      * This is used to determine if two keys are the same. Ultimately 
      * two keys are equal if they represent the same contact and
      * annotation from that contact. If everything is equal by
      * identity then this will be true.
      * 
      * @param key this is the value to compare to this key
      * 
      * @return this returns true if both keys have the same data
      */
     private boolean equals(LabelKey key) {
        if(key == this) {
           return true;
        }
        if(key.label != label) {
           return false;
        }
        if(key.owner != owner) {
           return false;
        }
        if(key.type != type) {
           return false;
        }
        return key.name.equals(name);
     }
     
     /**
      * This returns a string representation of this key. It contains
      * the name and the declaring class for the method or field.
      * This is primarily used for debugging purposes.
      * 
      * @return this returns a string representation of this key
      */
     public String toString() {
        return String.format("key '%s' for %s", name, owner);
     }
  }
  