AbstractKeyValue.java
- /*
- * 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.commons.collections4.keyvalue;
- import org.apache.commons.collections4.KeyValue;
- /**
- * Abstract pair class to assist with creating {@code KeyValue}
- * and {@link java.util.Map.Entry Map.Entry} implementations.
- *
- * @param <K> the type of keys
- * @param <V> the type of values
- * @since 3.0
- */
- public abstract class AbstractKeyValue<K, V> implements KeyValue<K, V> {
- /** The key */
- private K key;
- /** The value */
- private V value;
- /**
- * Constructs a new pair with the specified key and given value.
- *
- * @param key the key for the entry, may be null
- * @param value the value for the entry, may be null
- */
- protected AbstractKeyValue(final K key, final V value) {
- this.key = key;
- this.value = value;
- }
- /**
- * Gets the key from the pair.
- *
- * @return the key
- */
- @Override
- public K getKey() {
- return key;
- }
- /**
- * Gets the value from the pair.
- *
- * @return the value
- */
- @Override
- public V getValue() {
- return value;
- }
- /**
- * Sets the key.
- *
- * @param key The key.
- * @return The previous key.
- */
- protected K setKey(final K key) {
- final K old = this.key;
- this.key = key;
- return old;
- }
- /**
- * Sets the value.
- *
- * @param value The value.
- * @return The previous value.
- */
- protected V setValue(final V value) {
- final V old = this.value;
- this.value = value;
- return old;
- }
- /**
- * Gets a debugging String view of the pair.
- *
- * @return a String view of the entry
- */
- @Override
- public String toString() {
- return new StringBuilder()
- .append(getKey())
- .append('=')
- .append(getValue())
- .toString();
- }
- }