com.nytimes.android.external.cache3.Preconditions Maven / Gradle / Ivy

Go to download
/*
 * Copyright (C) 2016 Google, Inc.
 *
 * 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.nytimes.android.external.cache3;




import static java.lang.String.format;

/**
 * An adaptation of Guava's {@code com.google.common.base.Preconditions} that is specially tailored
 * to support checks applied in Dagger's generated code.
 */
public final class Preconditions {
  /**
   * Ensures that an object reference passed as a parameter to the calling method is not null.
   *
   * @param reference an object reference
   * @return the non-null reference that was validated
   * @throws NullPointerException if {@code reference} is null
   */
  public static  T checkNotNull(T reference) {
    if (reference == null) {
      throw new NullPointerException();
    }
    return reference;
  }

  /**
   * Ensures that an object reference passed as a parameter to the calling method is not null.
   *
   * @param reference an object reference
   * @param errorMessage the exception message to use if the check fails
   * @return the non-null reference that was validated
   * @throws NullPointerException if {@code reference} is null
   */
  public static  T checkNotNull(T reference, String errorMessage) {
    if (reference == null) {
      throw new NullPointerException(errorMessage);
    }
    return reference;
  }

  private Preconditions() {}

  public static void checkArgument(boolean expression) {
    if (!expression) {
      throw new IllegalArgumentException();
    }
  }

  /**
   * Ensures the truth of an expression involving one or more parameters to the calling method.
   *
   * @param expression a boolean expression
   * @param errorMessage the exception message to use if the check fails; will be converted to a
   *     string using {@link String#valueOf(Object)}
   * @throws IllegalArgumentException if {@code expression} is false
   */
  public static void checkArgument(boolean expression,   Object errorMessage) {
    if (!expression) {
      throw new IllegalArgumentException(String.valueOf(errorMessage));
    }
  }

  /**
   * Ensures the truth of an expression involving one or more parameters to the calling method.
   *
   * @param expression a boolean expression
   * @param errorMessageTemplate a template for the exception message should the check fail. The
   *     message is formed by replacing each {@code %s} placeholder in the template with an
   *     argument. These are matched by position - the first {@code %s} gets {@code
   *     errorMessageArgs[0]}, etc.  Unmatched arguments will be appended to the formatted message
   *     in square braces. Unmatched placeholders will be left as-is.
   * @param errorMessageArgs the arguments to be substituted into the message template. Arguments
   *     are converted to strings using {@link String#valueOf(Object)}.
   * @throws IllegalArgumentException if {@code expression} is false
   * @throws NullPointerException if the check fails and either {@code errorMessageTemplate} or
   *     {@code errorMessageArgs} is null (don't let this happen)
   */
  public static void checkArgument(
          boolean expression,
            String errorMessageTemplate,
            Object... errorMessageArgs) {
    if (!expression) {
      throw new IllegalArgumentException(format(errorMessageTemplate, errorMessageArgs));
    }
  }

  public static void checkState(boolean expression) {
    if (!expression) {
      throw new IllegalStateException();
    }
  }

  /**
   * Ensures the truth of an expression involving the state of the calling instance, but not
   * involving any parameters to the calling method.
   *
   * @param expression a boolean expression
   * @param errorMessage the exception message to use if the check fails; will be converted to a
   *     string using {@link String#valueOf(Object)}
   * @throws IllegalStateException if {@code expression} is false
   */
  public static void checkState(boolean expression,   Object errorMessage) {
    if (!expression) {
      throw new IllegalStateException(String.valueOf(errorMessage));
    }
  }

  /**
   * Ensures the truth of an expression involving the state of the calling instance, but not
   * involving any parameters to the calling method.
   *
   * @param expression a boolean expression
   * @param errorMessageTemplate a template for the exception message should the check fail. The
   *     message is formed by replacing each {@code %s} placeholder in the template with an
   *     argument. These are matched by position - the first {@code %s} gets {@code
   *     errorMessageArgs[0]}, etc.  Unmatched arguments will be appended to the formatted message
   *     in square braces. Unmatched placeholders will be left as-is.
   * @param errorMessageArgs the arguments to be substituted into the message template. Arguments
   *     are converted to strings using {@link String#valueOf(Object)}.
   * @throws IllegalStateException if {@code expression} is false
   * @throws NullPointerException if the check fails and either {@code errorMessageTemplate} or
   *     {@code errorMessageArgs} is null (don't let this happen)
   */
  public static void checkState(
          boolean expression,
            String errorMessageTemplate,
            Object... errorMessageArgs) {
    if (!expression) {
      throw new IllegalStateException(format(errorMessageTemplate, errorMessageArgs));
    }
  }

}