/*
* 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.tinkerpop.gremlin.process.computer;
import java.io.Serializable;
/**
* @author Marko A. Rodriguez (http://markorodriguez.com)
*/
public final class KeyValue<K, V> implements Serializable {
private final K key;
private final V value;
private static final String EMPTY_STRING = "";
private static final String TAB = "\t";
private static final String NULL = "null";
public KeyValue(final K key, final V value) {
this.key = key;
this.value = value;
}
public K getKey() {
return this.key;
}
public V getValue() {
return this.value;
}
public String toString() {
if (this.key instanceof MapReduce.NullObject && this.value instanceof MapReduce.NullObject) {
return EMPTY_STRING;
} else if (this.key instanceof MapReduce.NullObject) {
return makeString(this.value);
} else if (this.value instanceof MapReduce.NullObject) {
return makeString(this.key);
} else {
return makeString(this.key) + TAB + makeString(this.value);
}
}
private static final String makeString(final Object object) {
return null == object ? NULL : object.toString();
}
}