geode-core/src/main/java/org/apache/geode/services/result/impl/Failure.java

/*
 * 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.geode.services.result.impl;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.function.Consumer;
import java.util.function.Function;

import org.apache.commons.lang3.StringUtils;

import org.apache.geode.services.result.ServiceResult;

/**
 * This type of {@link ServiceResult} represents a failed operation. It contains the
 * errorMessage for the failure.
 *
 * @param <SuccessType> the result type for a successful operation. Not used by the {@link Failure}
 *        type but required by the {@link ServiceResult}
 *
 * @since 1.14.0
 *
 * @see ServiceResult
 * @see Success
 */
public class Failure<SuccessType> implements ServiceResult<SuccessType> {

  private final String errorMessage;

  private Failure(String errorMessage) {
    this.errorMessage = errorMessage;
  }

  /**
   * Creates a {@link Failure} object containing the errorMessage
   *
   * @param <T> the type of the result
   * @param errorMessage the error message describing the reason for failure.
   * @return an {@link Failure} instance containing the errorMessage
   */
  public static <T> Failure<T> of(String errorMessage) {
    if (StringUtils.isBlank(errorMessage)) {
      throw new IllegalArgumentException("Error message cannot be null or empty");
    }
    return new Failure<>(errorMessage);
  }

  /**
   * Creates a {@link Failure} object containing the throwable
   *
   * @param <T> the type of the result
   * @param throwable the error message describing the reason for failure.
   * @return an {@link Failure} instance containing the throwable
   */
  public static <T> Failure<T> of(Throwable throwable) {
    if (throwable == null) {
      throw new IllegalArgumentException("Error message cannot be null or empty");
    }
    StringWriter stringWriter = new StringWriter();
    try (PrintWriter printWriter = new PrintWriter(stringWriter)) {
      throwable.printStackTrace(printWriter);
      return new Failure<>(stringWriter.toString());
    }
  }

  /**
   * Creates a {@link Failure} object containing the errorMessage
   *
   * @param <T> the type of the result
   * @param errorMessage the error message describing the reason for failure.
   * @param throwable the throwable that caused the failure
   * @return an {@link Failure} instance containing the errorMessage
   */
  public static <T> Failure<T> of(String errorMessage, Throwable throwable) {
    if (throwable == null || StringUtils.isBlank(errorMessage)) {
      throw new IllegalArgumentException("Error message cannot be null or empty");
    }
    StringWriter stringWriter = new StringWriter();
    try (PrintWriter printWriter = new PrintWriter(stringWriter)) {
      throwable.printStackTrace(printWriter);
      return new Failure<>(errorMessage + "\n" + stringWriter);
    }
  }

  @Override
  public <T> T map(Function<SuccessType, T> successFunction, Function<String, T> errorFunction) {
    return errorFunction.apply(errorMessage);
  }

  @Override
  public SuccessType getMessage() {
    throw new RuntimeException("This Result is not of type Success.");
  }

  @Override
  public String getErrorMessage() {
    return errorMessage;
  }

  public ServiceResult<SuccessType> ifFailure(
      Consumer<? super String> consumer) {
    if (isFailure()) {
      consumer.accept(errorMessage);
    }
    return this;
  }

  @Override
  public boolean isFailure() {
    return true;
  }
}