Add ability to override JSR-352 baseContext.xml

While existing functionality provided the ability to override the
components provided in the baseContext.xml (as required for JSR-352
functionality) at a job by job level, this commit allows a user to
specify a base context for all of the JSR-352 based jobs within a JVM.
To set the location of the custom base context, a JVM property
JSR-352-BASE-CONTEXT should be set.

BATCH-2290

spring-batch-core/src/main/java/org/springframework/batch/core/jsr/configuration/support/BaseContextListFactoryBean.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2014 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.batch.core.jsr.configuration.support;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.springframework.beans.factory.FactoryBean;
+
+/**
+ * A simple factory bean that consolidates the list of locations to look for the base context for the JSR-352
+ * functionality
+ *
+ * @author Michael Minella
+ * @since 3.0.3
+ */
+public class BaseContextListFactoryBean implements FactoryBean<List<String>>{
+
+	@Override
+	public List<String> getObject() throws Exception {
+		String overrideContextLocation = System.getProperty("JSR-352-BASE-CONTEXT");
+
+		List<String> contextLocations = new ArrayList<String>(2);
+
+		contextLocations.add("baseContext.xml");
+
+		if(overrideContextLocation != null) {
+			contextLocations.add(overrideContextLocation);
+		}
+
+		return contextLocations;
+	}
+
+	@Override
+	public Class<?> getObjectType() {
+		return List.class;
+	}
+
+	@Override
+	public boolean isSingleton() {
+		return true;
+	}
+}

spring-batch-core/src/main/java/org/springframework/batch/core/jsr/launch/JsrJobOperator.java

@@ -122,6 +122,9 @@ import org.springframework.util.Assert;
  * 	</bean>
  * </beans>
  *
+ * A custom configuration of the above components can be specified by providing a system property JSR-352-BASE-CONTEXT.
+ * The location that is provided by this system property will override any beans as defined in baseContext.xml.
+ *
  * Calls to {@link JobOperator#start(String, Properties)} will provide a child context to the above context
  * using the job definition and batch.xml if provided.
  *
@@ -200,6 +203,12 @@ public class JsrJobOperator implements JobOperator, InitializingBean {
 		this.jobRepository = jobRepository;
 	}
 
+	public void setTransactionManager(PlatformTransactionManager transactionManager) {
+		Assert.notNull(transactionManager, "A PlatformTransactionManager is required");
+
+		this.transactionManager = transactionManager;
+	}
+
 	public void setTaskExecutor(TaskExecutor taskExecutor) {
 		this.taskExecutor = taskExecutor;
 	}

spring-batch-core/src/main/resources/beanRefContext.xml

@@ -5,10 +5,9 @@
                     http://www.springframework.org/schema/beans/spring-beans.xsd">
 
  	<bean id="baseContext" class="org.springframework.context.support.GenericXmlApplicationContext">
- 		<constructor-arg>
- 			<list>
- 				<value>baseContext.xml</value>
- 			</list>
- 		</constructor-arg>
+ 		<constructor-arg ref="baseContextList"/>
  	</bean>
+
+	<bean id="baseContextList"
+		  class="org.springframework.batch.core.jsr.configuration.support.BaseContextListFactoryBean"/>
 </beans>

spring-batch-core/src/test/java/org/springframework/batch/core/jsr/launch/JsrJobOperatorTests.java

@@ -23,8 +23,11 @@ import static org.junit.Assert.fail;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
 import java.util.ArrayList;
 import java.util.Date;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Properties;
@@ -62,8 +65,10 @@ import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.core.step.JobRepositorySupport;
 import org.springframework.batch.support.transaction.ResourcelessTransactionManager;
 import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.context.access.ContextSingletonBeanFactoryLocator;
 import org.springframework.core.task.AsyncTaskExecutor;
 import org.springframework.core.task.SyncTaskExecutor;
+import org.springframework.test.util.ReflectionTestUtils;
 
 public class JsrJobOperatorTests extends AbstractJsrTestCase {
 
@@ -76,7 +81,9 @@ public class JsrJobOperatorTests extends AbstractJsrTestCase {
 	private static final long TIMEOUT = 10000L;
 
 	@Before
-	public void setup() {
+	public void setup() throws Exception {
+		resetBaseContext();
+
 		MockitoAnnotations.initMocks(this);
 		parameterConverter = new JobParametersConverterSupport();
 		jsrJobOperator = new JsrJobOperator(jobExplorer, jobRepository, parameterConverter, new ResourcelessTransactionManager());
@@ -117,6 +124,38 @@ public class JsrJobOperatorTests extends AbstractJsrTestCase {
 		new JsrJobOperator(new SimpleJobExplorer(null, null, null, null), new JobRepositorySupport(), parameterConverter, new ResourcelessTransactionManager());
 	}
 
+	@Test
+	public void testCustomBaseContext() throws Exception {
+		System.setProperty("JSR-352-BASE-CONTEXT", "META-INF/alternativeJsrBaseContext.xml");
+
+		JobOperator jobOperator = BatchRuntime.getJobOperator();
+
+		Object transactionManager = ReflectionTestUtils.getField(jobOperator, "transactionManager");
+		assertTrue(transactionManager instanceof ResourcelessTransactionManager);
+
+		long executionId = jobOperator.start("longRunningJob", null);
+		// Give the job a chance to get started
+		Thread.sleep(1000L);
+		jobOperator.stop(executionId);
+		// Give the job the chance to finish stopping
+		Thread.sleep(1000L);
+
+		assertEquals(BatchStatus.STOPPED, jobOperator.getJobExecution(executionId).getBatchStatus());
+
+		System.getProperties().remove("JSR-352-BASE-CONTEXT");
+	}
+
+	private void resetBaseContext() throws NoSuchFieldException, IllegalAccessException {
+		Field instancesField = ContextSingletonBeanFactoryLocator.class.getDeclaredField("instances");
+		instancesField.setAccessible(true);
+
+		Field instancesModifiers = Field.class.getDeclaredField("modifiers");
+		instancesModifiers.setAccessible(true);
+		instancesModifiers.setInt(instancesField, instancesField.getModifiers() & ~Modifier.FINAL);
+
+		instancesField.set(null, new HashMap());
+	}
+
 	@Test
 	public void testDefaultTaskExecutor() throws Exception {
 		JsrJobOperator jsrJobOperatorImpl = (JsrJobOperator) jsrJobOperator;

spring-batch-core/src/test/resources/META-INF/alternativeJsrBaseContext.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	   xsi:schemaLocation="http://www.springframework.org/schema/beans
+                    http://www.springframework.org/schema/beans/spring-beans.xsd">
+
+	<bean id="transactionManager"
+		  class="org.springframework.batch.support.transaction.ResourcelessTransactionManager"/>
+</beans>