| /* |
| * Copyright (C) 2017 The Android Open Source Project |
| * |
| * Licensed 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 android.provider; |
| |
| /** |
| * A builder that facilitates prohibiting its use after an instance was created with it. |
| * |
| * Suggested usage: |
| * call {@link #checkNotUsed} in each setter, and {@link #markUsed} in {@link #build} |
| * |
| * @param <T> Type of object being built |
| * @hide |
| */ |
| public abstract class OneTimeUseBuilder<T> { |
| private boolean used = false; |
| |
| protected void markUsed() { |
| checkNotUsed(); |
| used = true; |
| } |
| |
| protected void checkNotUsed() { |
| if (used) { |
| throw new IllegalStateException( |
| "This Builder should not be reused. Use a new Builder instance instead"); |
| } |
| } |
| |
| /** |
| * Builds the instance |
| * |
| * Once this method is called, this builder should no longer be used. Any subsequent calls to a |
| * setter or {@code build()} will throw an exception |
| */ |
| public abstract T build(); |
| } |