/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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 io.netty.util;
Key which can be used to access Attribute
out of the AttributeMap
. Be aware that it is not be possible to have multiple keys with the same name. Type parameters: - <T> – the type of the
Attribute
which can be accessed via this AttributeKey
.
/**
* Key which can be used to access {@link Attribute} out of the {@link AttributeMap}. Be aware that it is not be
* possible to have multiple keys with the same name.
*
* @param <T> the type of the {@link Attribute} which can be accessed via this {@link AttributeKey}.
*/
@SuppressWarnings("UnusedDeclaration") // 'T' is used only at compile time
public final class AttributeKey<T> extends AbstractConstant<AttributeKey<T>> {
private static final ConstantPool<AttributeKey<Object>> pool = new ConstantPool<AttributeKey<Object>>() {
@Override
protected AttributeKey<Object> newConstant(int id, String name) {
return new AttributeKey<Object>(id, name);
}
};
Returns the singleton instance of the AttributeKey
which has the specified name
. /**
* Returns the singleton instance of the {@link AttributeKey} which has the specified {@code name}.
*/
@SuppressWarnings("unchecked")
public static <T> AttributeKey<T> valueOf(String name) {
return (AttributeKey<T>) pool.valueOf(name);
}
/**
* Returns {@code true} if a {@link AttributeKey} exists for the given {@code name}.
*/
public static boolean exists(String name) {
return pool.exists(name);
}
Creates a new AttributeKey
for the given name
or fail with an IllegalArgumentException
if a AttributeKey
for the given name
exists. /**
* Creates a new {@link AttributeKey} for the given {@code name} or fail with an
* {@link IllegalArgumentException} if a {@link AttributeKey} for the given {@code name} exists.
*/
@SuppressWarnings("unchecked")
public static <T> AttributeKey<T> newInstance(String name) {
return (AttributeKey<T>) pool.newInstance(name);
}
@SuppressWarnings("unchecked")
public static <T> AttributeKey<T> valueOf(Class<?> firstNameComponent, String secondNameComponent) {
return (AttributeKey<T>) pool.valueOf(firstNameComponent, secondNameComponent);
}
private AttributeKey(int id, String name) {
super(id, name);
}
}