52 lines
1.5 KiB
Java
52 lines
1.5 KiB
Java
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/*
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* Copyright (C) 2017 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.provider;
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/**
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* A builder that facilitates prohibiting its use after an instance was created with it.
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*
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* Suggested usage:
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* call {@link #checkNotUsed} in each setter, and {@link #markUsed} in {@link #build}
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*
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* @param <T> Type of object being built
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* @hide
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*/
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public abstract class OneTimeUseBuilder<T> {
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private boolean used = false;
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protected void markUsed() {
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checkNotUsed();
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used = true;
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}
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protected void checkNotUsed() {
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if (used) {
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throw new IllegalStateException(
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"This Builder should not be reused. Use a new Builder instance instead");
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}
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}
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/**
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* Builds the instance
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*
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* Once this method is called, this builder should no longer be used. Any subsequent calls to a
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* setter or {@code build()} will throw an exception
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*/
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public abstract T build();
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}
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