content: /*
   *  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
   *
   *      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 org.apache.tools.ant.types.resources;
  
  import java.util.Collection;
  import java.util.List;
  import java.util.stream.Collectors;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.Project;
  import org.apache.tools.ant.types.Resource;
  import org.apache.tools.ant.types.ResourceCollection;
  
  /**
   * ResourceCollection that contains the last <code>count</code> elements of
   * another ResourceCollection, a la the UNIX tail command.
   * @since Ant 1.7.1
   */
  public class Last extends SizeLimitCollection {
  
      /**
       * Take the last <code>count</code> elements.
       * @return a Collection of Resources.
       */
      @Override
      protected Collection<Resource> getCollection() {
          int count = getValidCount();
          ResourceCollection rc = getResourceCollection();
          int size = rc.size();
          int skip = Math.max(0, size - count);
  
          List<Resource> result =
              rc.stream().skip(skip).collect(Collectors.toList());
  
          int found = result.size();
          if (found == count || (size < count && found == size)) {
              return result;
          }
          //mismatch:
          String msg = String.format(
              "Resource collection %s reports size %d but returns %d elements.",
              rc, size, found + skip);
  
          //size was understated -> too many results; warn and continue:
          if (found > count) {
              log(msg, Project.MSG_WARN);
              return result.subList(found - count, found);
          }
          //size was overstated; we missed some and are now in error-land:
          throw new BuildException(msg);
      }
  
  }
  