com.github.javaparser.ast.DataKey Maven / Gradle / Ivy
/*
* Copyright (C) 2007-2010 Júlio Vilmar Gesser.
* Copyright (C) 2011, 2013-2023 The JavaParser Team.
*
* This file is part of JavaParser.
*
* JavaParser can be used either under the terms of
* a) the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* b) the terms of the Apache License
*
* You should have received a copy of both licenses in LICENCE.LGPL and
* LICENCE.APACHE. Please refer to those files for details.
*
* JavaParser 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 Lesser General Public License for more details.
*/
package com.github.javaparser.ast;
/**
* A key to a piece of data associated with a {@link Node} at runtime.
* The key contains type information that can be used to check the
* type of any user data value for the key when the value is set. DataKey is abstract in order to
* force the creation of a subtype. That subtype is used to test for identity when looking for the
* user data because actual object identity would suffer from problems under serialization.
* So, the correct way to declare a DataKey is like this:
*
*
* {@code
* public static final DataKey ROLE = new DataKey() { };
* }
*
*
* This code was taken from the Wicket project.
*
* @param The type of the object which is stored
* @see Node#getData(DataKey)
*/
public abstract class DataKey {
@Override
public int hashCode() {
return getClass().hashCode();
}
/**
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
return obj != null && getClass().equals(obj.getClass());
}
}