org.apache.logging.log4j.util.ReadOnlyStringMap Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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 org.apache.logging.log4j.util;
import java.util.Map;
/**
* A read-only collection of String keys mapped to values of arbitrary type.
*
* Warning: part of the API, since it is used by {@link StringMap}.
*
* @since 2.7
*/
public interface ReadOnlyStringMap {
/**
* Returns a non-{@code null} mutable {@code Map} containing a snapshot of this data structure.
*
* @return a mutable copy of this data structure in {@code Map} form.
*/
Map toMap();
/**
* Returns {@code true} if this data structure contains the specified key, {@code false} otherwise.
*
* @param key the key whose presence to check. May be {@code null}.
* @return {@code true} if this data structure contains the specified key, {@code false} otherwise.
*/
boolean containsKey(String key);
/**
* Performs the given action for each key-value pair in this data structure
* until all entries have been processed or the action throws an exception.
*
* Some implementations may not support structural modifications (adding new elements or removing elements) while
* iterating over the contents. In such implementations, attempts to add or remove elements from the
* {@code BiConsumer}'s {@link BiConsumer#accept(Object, Object)} accept} method may cause a
* {@code ConcurrentModificationException} to be thrown.
*
*
* @param action The action to be performed for each key-value pair in this collection.
* @param type of the value.
* @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
* to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
* {@link #forEach(TriConsumer, Object)}.
*/
void forEach(final BiConsumer action);
/**
* Performs the given action for each key-value pair in this data structure
* until all entries have been processed or the action throws an exception.
*
* The third parameter lets callers pass in a stateful object to be modified with the key-value pairs,
* so the TriConsumer implementation itself can be stateless and potentially reusable.
*
*
* Some implementations may not support structural modifications (adding new elements or removing elements) while
* iterating over the contents. In such implementations, attempts to add or remove elements from the
* {@code TriConsumer}'s {@link TriConsumer#accept(Object, Object, Object) accept} method may cause a
* {@code ConcurrentModificationException} to be thrown.
*
*
* @param action The action to be performed for each key-value pair in this collection.
* @param state the object to be passed as the third parameter to each invocation on the specified
* triconsumer.
* @param type of the value.
* @param type of the third parameter.
* @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
* to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
* {@link #forEach(TriConsumer, Object)}.
*/
void forEach(final TriConsumer action, final S state);
/**
* Returns the value for the specified key, or {@code null} if the specified key does not exist in this collection.
*
* @param key the key whose value to return.
* @param The type of the value to be returned.
* @return the value for the specified key or {@code null}.
*/
V getValue(final String key);
/**
* Returns {@code true} if this collection is empty (size is zero), {@code false} otherwise.
* @return {@code true} if this collection is empty (size is zero).
*/
boolean isEmpty();
/**
* Returns the number of key-value pairs in this collection.
*
* @return the number of key-value pairs in this collection.
*/
int size();
}