Selects all elements from input collection which match the given predicate into an output collection. - Android java.util

Android examples for java.util:Collection Element

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Description

Selects all elements from input collection which match the given predicate into an output collection.

Demo Code

/*//from www .  j  av a 2s.  c om
 * 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.
 */
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.function.Predicate;

public class Main {
  /**
   * Selects all elements from input collection which match the given predicate
   * into an output collection.
   * <p>
   * A <code>null</code> predicate matches no elements.
   * 
   * @param inputCollection
   *          the collection to get the input from, may not be null
   * @param predicate
   *          the predicate to use, may be null
   * @return the elements matching the predicate (new list)
   * @throws NullPointerException
   *           if the input collection is null
   */
  public static <E> Collection<E> select(Collection<E> inputCollection, Predicate<E> predicate) {
    ArrayList<E> answer = new ArrayList<E>(inputCollection.size());
    select(inputCollection, predicate, answer);
    return answer;
  }

  /**
   * Selects all elements from input collection which match the given predicate
   * and adds them to outputCollection.
   * <p>
   * If the input collection or predicate is null, there is no change to the
   * output collection.
   * 
   * @param inputCollection
   *          the collection to get the input from, may be null
   * @param predicate
   *          the predicate to use, may be null
   * @param outputCollection
   *          the collection to output into, may not be null
   */
  public static <E> void select(Collection<E> inputCollection, Predicate<E> predicate, Collection<E> outputCollection) {
    if (inputCollection != null && predicate != null) {
      for (Iterator<E> iter = inputCollection.iterator(); iter.hasNext();) {
        E item = iter.next();
        if (predicate.test(item)) {
          outputCollection.add(item);
        }
      }
    }
  }
}

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