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1   /*
2    * Copyright 2012-2013 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  package org.springframework.batch.core.job.builder;
17  
18  import java.util.ArrayList;
19  import java.util.List;
20  
21  import org.springframework.batch.core.Job;
22  import org.springframework.batch.core.Step;
23  import org.springframework.batch.core.job.SimpleJob;
24  import org.springframework.batch.core.job.flow.JobExecutionDecider;
25  import org.springframework.core.task.TaskExecutor;
26  import org.springframework.util.Assert;
27  
28  /**
29   * @author Dave Syer
30   * 
31   * @since 2.2
32   * 
33   */
34  public class SimpleJobBuilder extends JobBuilderHelper<SimpleJobBuilder> {
35  
36  	private List<Step> steps = new ArrayList<Step>();
37  
38  	private JobFlowBuilder builder;
39  
40  	/**
41  	 * Create a new builder initialized with any properties in the parent. The parent is copied, so it can be re-used.
42  	 * 
43  	 * @param parent the parent to use
44  	 */
45  	public SimpleJobBuilder(JobBuilderHelper<?> parent) {
46  		super(parent);
47  	}
48  
49  	public Job build() {
50  		if (builder != null) {
51  			return builder.end().build();
52  		}
53  		SimpleJob job = new SimpleJob(getName());
54  		super.enhance(job);
55  		job.setSteps(steps);
56  		try {
57  			job.afterPropertiesSet();
58  		}
59  		catch (Exception e) {
60  			throw new JobBuilderException(e);
61  		}
62  		return job;
63  	}
64  
65  	/**
66  	 * Start the job with this step.
67  	 * 
68  	 * @param step a step to start with
69  	 * @return this for fluent chaining
70  	 */
71  	public SimpleJobBuilder start(Step step) {
72  		if (steps.isEmpty()) {
73  			steps.add(step);
74  		}
75  		else {
76  			steps.set(0, step);
77  		}
78  		return this;
79  	}
80  
81  	/**
82  	 * Branch into a flow conditional on the outcome of the current step.
83  	 * 
84  	 * @param pattern a pattern for the exit status of the current step
85  	 * @return a builder for fluent chaining
86  	 */
87  	public FlowBuilder.TransitionBuilder<FlowJobBuilder> on(String pattern) {
88  		Assert.state(steps.size() > 0, "You have to start a job with a step");
89  		for (Step step : steps) {
90  			if (builder == null) {
91  				builder = new JobFlowBuilder(new FlowJobBuilder(this), step);
92  			}
93  			else {
94  				builder.next(step);
95  			}
96  		}
97  		return builder.on(pattern);
98  	}
99  
100 	/**
101 	 * Start with this decider. Returns a flow builder and when the flow is ended a job builder will be returned to
102 	 * continue the job configuration if needed.
103 	 * 
104 	 * @param decider a decider to execute first
105 	 * @return builder for fluent chaining
106 	 */
107 	public JobFlowBuilder start(JobExecutionDecider decider) {
108 		if (builder == null) {
109 			builder = new JobFlowBuilder(new FlowJobBuilder(this), decider);
110 		}
111 		else {
112 			builder.start(decider);
113 		}
114 		if (!steps.isEmpty()) {
115 			steps.remove(0);
116 		}
117 		for (Step step : steps) {
118 			builder.next(step);
119 		}
120 		return builder;
121 	}
122 
123 	/**
124 	 * Continue with this decider if the previous step was successful. Returns a flow builder and when the flow is ended
125 	 * a job builder will be returned to continue the job configuration if needed.
126 	 * 
127 	 * @param decider a decider to execute next
128 	 * @return builder for fluent chaining
129 	 */
130 	public JobFlowBuilder next(JobExecutionDecider decider) {
131 		for (Step step : steps) {
132 			if (builder == null) {
133 				builder = new JobFlowBuilder(new FlowJobBuilder(this), step);
134 			}
135 			else {
136 				builder.next(step);
137 			}
138 		}
139 		if (builder == null) {
140 			builder = new JobFlowBuilder(new FlowJobBuilder(this), decider);
141 		}
142 		else {
143 			builder.next(decider);
144 		}
145 		return builder;
146 	}
147 
148 	/**
149 	 * Continue or end a job with this step if the previous step was successful.
150 	 * 
151 	 * @param step a step to execute next
152 	 * @return this for fluent chaining
153 	 */
154 	public SimpleJobBuilder next(Step step) {
155 		steps.add(step);
156 		return this;
157 	}
158 
159 	/**
160 	 * @param executor
161 	 * @return builder for fluent chaining
162 	 */
163 	public JobFlowBuilder.SplitBuilder<FlowJobBuilder> split(TaskExecutor executor) {
164 		for (Step step : steps) {
165 			if (builder == null) {
166 				builder = new JobFlowBuilder(new FlowJobBuilder(this), step);
167 			}
168 			else {
169 				builder.next(step);
170 			}
171 		}
172 		if (builder == null) {
173 			builder = new JobFlowBuilder(new FlowJobBuilder(this));
174 		}
175 		return builder.split(executor);
176 	}
177 
178 }