[bs-55] Add strategy for setting system exit code

* Added ExitCodeGenerator and SpringApplication.exit
convenience method
* User can add bean of type ExitCodeGenerator or supply
one in the call to exit()

[Fixes #48475971]

spring-bootstrap-samples/spring-bootstrap-batch-sample/src/main/java/org/springframework/bootstrap/sample/batch/BatchBootstrapApplication.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2012-2013 the original author or authors.
+ *
+ * Licensed 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.springframework.bootstrap.sample.batch;
+
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.Step;
+import org.springframework.batch.core.StepContribution;
+import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
+import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
+import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
+import org.springframework.batch.core.scope.context.ChunkContext;
+import org.springframework.batch.core.step.tasklet.Tasklet;
+import org.springframework.batch.repeat.RepeatStatus;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.bootstrap.SpringApplication;
+import org.springframework.bootstrap.context.annotation.EnableAutoConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@EnableAutoConfiguration
+@ComponentScan
+@EnableBatchProcessing
+public class BatchBootstrapApplication {
+
+	@Autowired
+	private JobBuilderFactory jobs;
+
+	@Autowired
+	private StepBuilderFactory steps;
+
+	@Bean
+	protected Tasklet tasklet() {
+		return new Tasklet() {
+			@Override
+			public RepeatStatus execute(StepContribution contribution,
+					ChunkContext context) {
+				return RepeatStatus.FINISHED;
+			}
+		};
+	}
+
+	@Bean
+	public Job job() throws Exception {
+		return this.jobs.get("job").start(step1()).build();
+	}
+
+	@Bean
+	protected Step step1() throws Exception {
+		return this.steps.get("step1").tasklet(tasklet()).build();
+	}
+
+	public static void main(String[] args) throws Exception {
+		// System.exit is common for Batch applications since the exit code can be used to
+		// drive a workflow
+		System.exit(SpringApplication.exit(SpringApplication.run(
+				BatchBootstrapApplication.class, args)));
+	}
+}

spring-bootstrap-samples/spring-bootstrap-batch-sample/src/test/java/org/springframework/bootstrap/sample/batch/BatchBootstrapApplicationTests.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2012-2013 the original author or authors.
+ *
+ * Licensed 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.springframework.bootstrap.sample.batch;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.bootstrap.SpringApplication;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class BatchBootstrapApplicationTests {
+
+	private PrintStream savedOutput;
+	private ByteArrayOutputStream output;
+
+	@Before
+	public void init() {
+		this.savedOutput = System.err;
+		this.output = new ByteArrayOutputStream();
+		// jdk logging goes to syserr by default
+		System.setErr(new PrintStream(this.output));
+	}
+
+	@After
+	public void after() {
+		System.setErr(this.savedOutput);
+	}
+
+	private String getOutput() {
+		return this.output.toString();
+	}
+
+	@Test
+	public void testDefaultSettings() throws Exception {
+		assertEquals(0, SpringApplication.exit(SpringApplication
+				.run(BatchBootstrapApplication.class)));
+		String output = getOutput();
+		assertTrue("Wrong output: " + output,
+				output.contains("completed with the following parameters"));
+	}
+
+}