com.github.hilcode.versionator.Result.java Source code

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Here is the source code for com.github.hilcode.versionator.Result.java

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/*
 * Copyright (C) 2016 H.C. Wijbenga
 *
 * 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 com.github.hilcode.versionator;

import com.google.common.base.Preconditions;

public final class Result<F, S> {
    public static final <F, S> Result<F, S> success(final S value) {
        return new Result<>(null, value);
    }

    public static final <ANY, F, S> Result<F, S> asSuccess(final Result<ANY, S> result) {
        Preconditions.checkArgument(result.isSuccess(), "Invalid cast, this Result represents a Failure.");
        @SuppressWarnings("unchecked")
        final Result<F, S> result_ = (Result<F, S>) result;
        return result_;
    }

    public static final <F, S> Result<F, S> failure(final F value) {
        return new Result<>(value, null);
    }

    public static final <ANY, F, S> Result<F, S> asFailure(final Result<F, ANY> result) {
        Preconditions.checkArgument(result.isFailure(), "Invalid cast, this Result represents a Success.");
        @SuppressWarnings("unchecked")
        final Result<F, S> result_ = (Result<F, S>) result;
        return result_;
    }

    private final F failure;

    private final S success;

    private Result(final F failure, final S success) {
        Preconditions.checkArgument(failure != null && success == null || failure == null && success != null,
                "Invalid failure/success.");
        this.failure = failure;
        this.success = success;
    }

    public boolean isFailure() {
        return this.failure != null;
    }

    public boolean isSuccess() {
        return this.success != null;
    }

    public F failure() {
        Preconditions.checkNotNull(this.failure, "This Result represents a success.");
        return this.failure;
    }

    public S success() {
        Preconditions.checkNotNull(this.success, "This Result represents a failure.");
        return this.success;
    }
}