1 /*
2 * (c) Copyright 2006-2020 by rapiddweller GmbH & Volker Bergmann. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, is permitted under the terms of the
6 * GNU General Public License.
7 *
8 * For redistributing this software or a derivative work under a license other
9 * than the GPL-compatible Free Software License as defined by the Free
10 * Software Foundation or approved by OSI, you must first obtain a commercial
11 * license to this software product from rapiddweller GmbH & Volker Bergmann.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
14 * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
15 * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
17 * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
18 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
20 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
21 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
22 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
23 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 * POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 package com.rapiddweller.task;
28
29 import com.rapiddweller.common.BeanUtil;
30 import com.rapiddweller.common.Context;
31 import com.rapiddweller.common.ErrorHandler;
32
33 /**
34 * Task proxy that remembers the result of the last execution step and provides it as
35 * property <code>available</code>.<br/><br/>
36 * Created: 05.02.2010 10:41:55
37 *
38 * @param <E> the type parameter
39 * @author Volker Bergmann
40 * @since 0.6
41 */
42 public class StateTrackingTaskProxy<E extends Task> extends TaskProxy<E> {
43
44 /**
45 * The State.
46 */
47 protected volatile TaskResult state;
48
49 /**
50 * Instantiates a new State tracking task proxy.
51 *
52 * @param realTask the real task
53 */
54 public StateTrackingTaskProxy(E realTask) {
55 super(realTask);
56 this.state = TaskResult.EXECUTING;
57 }
58
59 /**
60 * Is available boolean.
61 *
62 * @return the boolean
63 */
64 public boolean isAvailable() {
65 return (state != TaskResult.EXECUTING);
66 }
67
68 @Override
69 public TaskResult execute(Context context, ErrorHandler errorHandler) {
70 if (isAvailable()) {
71 return TaskResult.UNAVAILABLE;
72 }
73 TaskResult result = super.execute(context, errorHandler);
74 state = result;
75 return result; // avoiding synchronization issues using a local variable instead of 'state' attribute
76 }
77
78 @Override
79 public StateTrackingTaskProxy<E> clone() {
80 return new StateTrackingTaskProxy<>(BeanUtil.clone(realTask));
81 }
82
83 @Override
84 public String toString() {
85 return getClass().getSimpleName() + '[' + realTask.toString() + ']';
86 }
87
88 }