| /* |
| * 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); |
| } |
| |
| } |