/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2009 Sun Microsystems, Inc.
 */

package com.sun.opends.sdk.util;



/**
 * Common methods for validating method arguments.
 */
public final class Validator
{

  /**
   * Throws a {@code NullPointerException} if the provided argument is
   * {@code null}. This method returns a reference to its single
   * parameter so that it can be easily used in constructors.
   *
   * @param <T>
   *          The type of {@code o1}.
   * @param o1
   *          The object to test.
   * @return A reference to {@code o1}.
   * @throws NullPointerException
   *           If the provided argument is {@code null}.
   */
  public static <T> T ensureNotNull(T o1) throws NullPointerException
  {
    if (o1 == null)
    {
      throw new NullPointerException();
    }
    return o1;
  }



  /**
   * Throws a {@code NullPointerException} if any of the provided
   * arguments are {@code null}.
   *
   * @param o1
   *          The first object to test.
   * @param o2
   *          The second object to test.
   * @throws NullPointerException
   *           If any of the provided arguments are {@code null}.
   */
  public static void ensureNotNull(Object o1, Object o2)
      throws NullPointerException
  {
    if (o1 == null || o2 == null)
    {
      throw new NullPointerException();
    }
  }



  /**
   * Throws a {@code NullPointerException} if any of the provided
   * arguments are {@code null}.
   *
   * @param o1
   *          The first object to test.
   * @param o2
   *          The second object to test.
   * @param o3
   *          The third object to test.
   * @throws NullPointerException
   *           If any of the provided arguments are {@code null}.
   */
  public static void ensureNotNull(Object o1, Object o2, Object o3)
      throws NullPointerException
  {
    if (o1 == null || o2 == null || o3 == null)
    {
      throw new NullPointerException();
    }
  }



  /**
   * Throws a {@code NullPointerException} if any of the provided
   * arguments are {@code null}.
   *
   * @param o1
   *          The first object to test.
   * @param o2
   *          The second object to test.
   * @param o3
   *          The third object to test.
   * @param o4
   *          The fourth object to test.
   * @throws NullPointerException
   *           If any of the provided arguments are {@code null}.
   */
  public static void ensureNotNull(Object o1, Object o2, Object o3,
      Object o4) throws NullPointerException
  {
    if (o1 == null || o2 == null || o3 == null || o4 == null)
    {
      throw new NullPointerException();
    }
  }



  /**
   * Throws a {@code NullPointerException} if any of the provided
   * arguments are {@code null}.
   *
   * @param o1
   *          The first object to test.
   * @param o2
   *          The second object to test.
   * @param o3
   *          The third object to test.
   * @param o4
   *          The fourth object to test.
   * @param o5
   *          The fifth object to test.
   * @throws NullPointerException
   *           If any of the provided arguments are {@code null}.
   */
  public static void ensureNotNull(Object o1, Object o2, Object o3,
      Object o4, Object o5) throws NullPointerException
  {
    if (o1 == null || o2 == null || o3 == null || o4 == null
        || o5 == null)
    {
      throw new NullPointerException();
    }
  }



  /**
   * Throws a {@code NullPointerException} if any of the provided
   * arguments are {@code null}.
   *
   * @param objects
   *          The objects to test.
   * @throws NullPointerException
   *           If any of the provided arguments are {@code null}.
   */
  public static void ensureNotNull(Object... objects)
      throws NullPointerException
  {
    for (Object o : objects)
    {
      if (o == null)
      {
        throw new NullPointerException();
      }
    }
  }



  /**
   * Throws an {@code IllegalArgumentException} if the provided
   * condition is {@code false}.
   *
   * @param condition
   *          The condition, which must be {@code true} to avoid an
   *          exception.
   * @param message
   *          The error message to include in the exception if it is
   *          thrown.
   * @throws IllegalArgumentException
   *           If {@code condition} was {@code false}.
   */
  public static void ensureTrue(boolean condition, String message)
      throws IllegalArgumentException
  {
    if (!condition)
    {
      throw new IllegalArgumentException(message);
    }
  }



  // Prevent instantiation.
  private Validator()
  {
    // No implementation required.
  }
}