| 1 | /* |
| 2 | * Copyright 2002-2007 the original author or authors. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.springframework.batch.repeat.support; |
| 18 | |
| 19 | import org.springframework.core.JdkVersion; |
| 20 | import org.springframework.util.ClassUtils; |
| 21 | |
| 22 | /** |
| 23 | * A factory that properly determines which version of the {@link ResultQueue} to return based on the availability of |
| 24 | * Java 5 or Backport Concurrent. |
| 25 | * |
| 26 | * @author Ben Hale |
| 27 | */ |
| 28 | class ResultQueueFactory { |
| 29 | |
| 30 | /** Whether the backport-concurrent library is present on the classpath */ |
| 31 | private static final boolean backportConcurrentAvailable = ClassUtils.isPresent( |
| 32 | "edu.emory.mathcs.backport.java.util.concurrent.Semaphore", ResultQueueFactory.class.getClassLoader()); |
| 33 | |
| 34 | public RepeatInternalState getResultQueue(int throttleLimit) { |
| 35 | if (JdkVersion.isAtLeastJava15()) { |
| 36 | return new JdkConcurrentResultQueue(throttleLimit); |
| 37 | } else if (backportConcurrentAvailable) { |
| 38 | return new BackportConcurrentResultQueue(throttleLimit); |
| 39 | } else { |
| 40 | throw new IllegalStateException("Cannot create ResultQueue - " |
| 41 | + "neither JDK 1.5 nor backport-concurrent available on the classpath"); |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | } |