| /* |
| * 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. |
| * |
| */ |
| package org.apache.tools.ant.types.resources; |
| |
| import java.util.Iterator; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| |
| import org.apache.tools.ant.BuildException; |
| import org.apache.tools.ant.Project; |
| 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. |
| */ |
| protected Collection getCollection() { |
| int count = getValidCount(); |
| ResourceCollection rc = getResourceCollection(); |
| int i = count; |
| Iterator iter = rc.iterator(); |
| int size = rc.size(); |
| for (; i < size; i++) { |
| iter.next(); |
| } |
| |
| ArrayList al = new ArrayList(count); |
| for (; iter.hasNext(); i++) { |
| al.add(iter.next()); |
| } |
| int found = al.size(); |
| if (found == count || (size < count && found == size)) { |
| return al; |
| } |
| |
| //mismatch: |
| String msg = "Resource collection " + rc + " reports size " + size |
| + " but returns " + i + " elements."; |
| |
| //size was understated -> too many results; warn and continue: |
| if (found > count) { |
| log(msg, Project.MSG_WARN); |
| return al.subList(found - count, found); |
| } |
| //size was overstated; we missed some and are now in error-land: |
| throw new BuildException(msg); |
| } |
| |
| } |