content: /*
   * Copyright 2002-2020 the original author or authors.
   *
   * 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
   *
   *      https://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.alibaba.ttl3.internal.util;
  
  
  ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  //
  // This source code file is copied from spring v5.3.24:
  //
  // https://github.com/spring-projects/spring-framework/blob/v5.3.24/spring-core/src/main/java/org/springframework/util/Assert.java
  //
  // with adoption:
  // - remove unused elements
  // - adjust visible modifier and code format
  //
  ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
  
  import edu.umd.cs.findbugs.annotations.Nullable;
  
  /**
   * Assertion utility class that assists in validating arguments.
   *
   * <p>Useful for identifying programmer errors early and clearly at runtime.
   *
   * <p>For example, if the contract of a public method states it does not
   * allow {@code null} arguments, {@code Assert} can be used to validate that
   * contract. Doing this clearly indicates a contract violation when it
   * occurs and protects the class's invariants.
   *
   * <p>Typically used to validate method arguments rather than configuration
   * properties, to check for cases that are usually programmer errors rather
   * than configuration errors. In contrast to configuration initialization
   * code, there is usually no point in falling back to defaults in such methods.
   *
   * <p>This class is similar to JUnit's assertion library. If an argument value is
   * deemed invalid, an {@link IllegalArgumentException} is thrown (typically).
   * For example:
   *
   * <pre class="code">
   * Assert.notNull(clazz, "The class must not be null");
   * Assert.isTrue(i &gt; 0, "The value must be greater than zero");</pre>
   *
   * <p>Mainly for internal use within the framework; for a more comprehensive suite
   * of assertion utilities consider {@code org.apache.commons.lang3.Validate} from
   * <a href="https://commons.apache.org/proper/commons-lang/">Apache Commons Lang</a>,
   * Google Guava's
   * <a href="https://github.com/google/guava/wiki/PreconditionsExplained">Preconditions</a>,
   * or similar third-party libraries.
   *
   * @author Keith Donald
   * @author Juergen Hoeller
   * @author Sam Brannen
   * @author Colin Sampaleanu
   * @author Rob Harrop
   */
  final class Assert {
  
      /**
       * Assert a boolean expression, throwing an {@code IllegalStateException}
       * if the expression evaluates to {@code false}.
       * <p>Call {@link #isTrue} if you wish to throw an {@code IllegalArgumentException}
       * on an assertion failure.
       * <pre class="code">Assert.state(id == null, "The id property must not already be initialized");</pre>
       *
       * @param expression a boolean expression
       * @param message    the exception message to use if the assertion fails
       * @throws IllegalStateException if {@code expression} is {@code false}
       */
      public static void state(boolean expression, String message) {
          if (!expression) {
              throw new IllegalStateException(message);
          }
      }
  
      /**
       * Assert a boolean expression, throwing an {@code IllegalArgumentException}
       * if the expression evaluates to {@code false}.
       * <pre class="code">Assert.isTrue(i &gt; 0, "The value must be greater than zero");</pre>
       *
       * @param expression a boolean expression
       * @param message    the exception message to use if the assertion fails
       * @throws IllegalArgumentException if {@code expression} is {@code false}
       */
      public static void isTrue(boolean expression, String message) {
          if (!expression) {
              throw new IllegalArgumentException(message);
          }
      }
  
      /**
       * Assert that an object is not {@code null}.
       * <pre class="code">Assert.notNull(clazz, "The class must not be null");</pre>
       *
       * @param object  the object to check
       * @param message the exception message to use if the assertion fails
       * @throws IllegalArgumentException if the object is {@code null}
       */
      public static void notNull(@Nullable Object object, String message) {
          if (object == null) {
              throw new IllegalArgumentException(message);
          }
      }
  
  }
  