| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| Limit |
|
| 1.8;1.8 |
| 1 | /* | |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
| 3 | * contributor license agreements. See the NOTICE file distributed with | |
| 4 | * this work for additional information regarding copyright ownership. | |
| 5 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
| 6 | * (the "License"); you may not use this file except in compliance with | |
| 7 | * the License. You may obtain a copy of the License at | |
| 8 | * | |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
| 10 | * | |
| 11 | * Unless required by applicable law or agreed to in writing, software | |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 14 | * See the License for the specific language governing permissions and | |
| 15 | * limitations under the License. | |
| 16 | */ | |
| 17 | package org.apache.commons.functor.core; | |
| 18 | ||
| 19 | import org.apache.commons.functor.BinaryPredicate; | |
| 20 | import org.apache.commons.functor.Predicate; | |
| 21 | import org.apache.commons.functor.UnaryPredicate; | |
| 22 | ||
| 23 | /** | |
| 24 | * A predicate that returns <code>true</code> | |
| 25 | * the first <i>n</i> times it is invoked. | |
| 26 | * | |
| 27 | * @since 1.0 | |
| 28 | * @version $Revision: 1160412 $ $Date: 2011-08-22 22:10:41 +0200 (Mon, 22 Aug 2011) $ | |
| 29 | * @author Jason Horman (jason@jhorman.org) | |
| 30 | * @author Rodney Waldhoff | |
| 31 | */ | |
| 32 | ||
| 33 | public final class Limit implements Predicate, UnaryPredicate<Object>, BinaryPredicate<Object, Object> { | |
| 34 | // instance variables | |
| 35 | //--------------------------------------------------------------- | |
| 36 | /** | |
| 37 | * The max number of times the predicate can be invoked. | |
| 38 | */ | |
| 39 | private final int max; | |
| 40 | /** | |
| 41 | * The current number of times the predicate has been invoked. | |
| 42 | */ | |
| 43 | private int current; | |
| 44 | ||
| 45 | /** | |
| 46 | * Create a new Limit. | |
| 47 | * @param count limit | |
| 48 | */ | |
| 49 | 34 | public Limit(int count) { |
| 50 | 34 | if (count < 0) { |
| 51 | 2 | throw new IllegalArgumentException("Argument must be a non-negative integer."); |
| 52 | } | |
| 53 | 32 | this.max = count; |
| 54 | 32 | } |
| 55 | ||
| 56 | /** | |
| 57 | * {@inheritDoc} | |
| 58 | */ | |
| 59 | public synchronized boolean test() { | |
| 60 | // stop incrementing when we've hit max, so we don't loop around | |
| 61 | 70 | if (current < max) { |
| 62 | 42 | current++; |
| 63 | 42 | return true; |
| 64 | } | |
| 65 | 28 | return false; |
| 66 | } | |
| 67 | ||
| 68 | /** | |
| 69 | * {@inheritDoc} | |
| 70 | */ | |
| 71 | public boolean test(Object obj) { | |
| 72 | 24 | return test(); |
| 73 | } | |
| 74 | ||
| 75 | /** | |
| 76 | * {@inheritDoc} | |
| 77 | */ | |
| 78 | public boolean test(Object a, Object b) { | |
| 79 | 8 | return test(); |
| 80 | } | |
| 81 | ||
| 82 | /** | |
| 83 | * {@inheritDoc} | |
| 84 | */ | |
| 85 | public String toString() { | |
| 86 | 6 | return "Limit<" + max + ">"; |
| 87 | } | |
| 88 | ||
| 89 | //default == equals/hashCode due to statefulness | |
| 90 | } |