Madan Jampani | f2f086c | 2016-01-13 16:15:39 -0800 | [diff] [blame] | 1 | /* |
Brian O'Connor | a09fe5b | 2017-08-03 21:12:30 -0700 | [diff] [blame] | 2 | * Copyright 2016-present Open Networking Foundation |
Madan Jampani | f2f086c | 2016-01-13 16:15:39 -0800 | [diff] [blame] | 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.onosproject.event; |
| 17 | |
| 18 | import com.google.common.base.MoreObjects; |
| 19 | import com.google.common.base.Objects; |
| 20 | |
| 21 | /** |
| 22 | * Generic representation of an update. |
| 23 | * |
| 24 | * @param <T> type of value that was updated |
| 25 | */ |
| 26 | public class Change<T> { |
| 27 | |
| 28 | private final T oldValue; |
| 29 | private final T newValue; |
| 30 | |
| 31 | public Change(T oldValue, T newValue) { |
| 32 | this.oldValue = oldValue; |
| 33 | this.newValue = newValue; |
| 34 | } |
| 35 | |
| 36 | /** |
| 37 | * Returns previous value. |
| 38 | * @return previous value. |
| 39 | */ |
| 40 | public T oldValue() { |
| 41 | return oldValue; |
| 42 | } |
| 43 | |
| 44 | /** |
| 45 | * Returns new or current value. |
| 46 | * @return new value. |
| 47 | */ |
| 48 | public T newValue() { |
| 49 | return newValue; |
| 50 | } |
| 51 | |
| 52 | @Override |
| 53 | public boolean equals(Object other) { |
| 54 | if (other == null || !(other instanceof Change)) { |
| 55 | return false; |
| 56 | } |
| 57 | Change<T> that = (Change<T>) other; |
| 58 | return Objects.equal(this.oldValue, that.oldValue) && |
| 59 | Objects.equal(this.newValue, that.newValue); |
| 60 | } |
| 61 | |
| 62 | @Override |
| 63 | public int hashCode() { |
| 64 | return Objects.hashCode(oldValue, newValue); |
| 65 | } |
| 66 | |
| 67 | @Override |
| 68 | public String toString() { |
| 69 | return MoreObjects.toStringHelper(getClass()) |
| 70 | .add("oldValue", oldValue) |
| 71 | .add("newValue", newValue) |
| 72 | .toString(); |
| 73 | } |
| 74 | } |