core/src/com/google/inject/internal/util/ObjectArrays.java

/*
 * Copyright (C) 2007 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.google.inject.internal.util;

import java.lang.reflect.Array;

/**
 * Static utility methods pertaining to object arrays.
 *
 * @author Kevin Bourrillion
 */
public final class ObjectArrays {
  private ObjectArrays() {}

  /**
   * Returns a new array of the given length with the same type as a reference
   * array.
   *
   * @param reference any array of the desired type
   * @param length the length of the new array
   */
  public static <T> T[] newArray(T[] reference, int length) {
    Class<?> type = reference.getClass().getComponentType();

    // the cast is safe because result.getClass() == reference.getClass()
    @SuppressWarnings("unchecked")
    T[] result = (T[]) Array.newInstance(type, length);
    return result;
  }
}