Fix NullAway findings

Signed-off-by: Stefano Cordio <stefano.cordio@gmail.com>

Author: scordio

pom.xml

@@ -191,6 +191,7 @@
 							<!-- Check JSpecify annotations -->
 							-Xep:NullAway:ERROR
 							-XepOpt:NullAway:OnlyNullMarked
+							-XepOpt:NullAway:CustomContractAnnotations=org.springframework.lang.Contract
 						</compilerArg>
 					</compilerArgs>
 					<annotationProcessorPaths>

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

@@ -222,7 +222,7 @@ private Collection<Job> doLoad(ApplicationContextFactory factory, boolean unregi
 	 * @return all the {@link Step} defined by the given step locator and context
 	 * @see StepLocator
 	 */
-	private Collection<Step> getSteps(final StepLocator stepLocator, final ApplicationContext jobApplicationContext) {
+	private Collection<Step> getSteps(StepLocator stepLocator, final ApplicationContext jobApplicationContext) {
 		final Collection<String> stepNames = stepLocator.getStepNames();
 		final Collection<Step> result = new ArrayList<>();
 		for (String stepName : stepNames) {

spring-batch-core/src/main/java/org/springframework/batch/core/job/flow/FlowJob.java

@@ -127,7 +127,7 @@ public Collection<String> getStepNames() {
 	 * @see AbstractJob#doExecute(JobExecution)
 	 */
 	@Override
-	protected void doExecute(final JobExecution execution) throws JobExecutionException {
+	protected void doExecute(JobExecution execution) throws JobExecutionException {
 		try {
 			JobFlowExecutor executor = new JobFlowExecutor(getJobRepository(),
 					new SimpleStepHandler(getJobRepository()), execution);

spring-batch-core/src/main/java/org/springframework/batch/core/job/flow/support/state/SplitState.java

@@ -97,13 +97,13 @@ public Collection<Flow> getFlows() {
 	 * @see State#handle(FlowExecutor)
 	 */
 	@Override
-	public FlowExecutionStatus handle(final FlowExecutor executor) throws Exception {
+	public FlowExecutionStatus handle(FlowExecutor executor) throws Exception {
 
 		// TODO: collect the last StepExecution from the flows as well, so they
 		// can be abandoned if necessary
 		Collection<Future<FlowExecution>> tasks = new ArrayList<>();
 
-		for (final Flow flow : flows) {
+		for (Flow flow : flows) {
 
 			final FutureTask<FlowExecution> task = new FutureTask<>(() -> flow.start(executor));
 

spring-batch-core/src/main/java/org/springframework/batch/core/launch/support/TaskExecutorJobLauncher.java

@@ -98,9 +98,8 @@ public class TaskExecutorJobLauncher implements JobLauncher, InitializingBean {
 	 * @throws JobParametersInvalidException thrown if jobParameters is invalid.
 	 */
 	@Override
-	public JobExecution run(final Job job, final JobParameters jobParameters)
-			throws JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException,
-			JobParametersInvalidException {
+	public JobExecution run(Job job, final JobParameters jobParameters) throws JobExecutionAlreadyRunningException,
+			JobRestartException, JobInstanceAlreadyCompleteException, JobParametersInvalidException {
 
 		Assert.notNull(job, "The Job must not be null.");
 		Assert.notNull(jobParameters, "The JobParameters must not be null.");

spring-batch-core/src/main/java/org/springframework/batch/core/partition/support/AbstractPartitionHandler.java

@@ -52,7 +52,7 @@ protected abstract Set<StepExecution> doHandle(StepExecution managerStepExecutio
 	 * @see PartitionHandler#handle(StepExecutionSplitter, StepExecution)
 	 */
 	@Override
-	public Collection<StepExecution> handle(final StepExecutionSplitter stepSplitter,
+	public Collection<StepExecution> handle(StepExecutionSplitter stepSplitter,
 			final StepExecution managerStepExecution) throws Exception {
 		final Set<StepExecution> stepExecutions = stepSplitter.split(managerStepExecution, gridSize);
 

spring-batch-core/src/main/java/org/springframework/batch/core/partition/support/TaskExecutorPartitionHandler.java

@@ -93,7 +93,7 @@ protected Set<StepExecution> doHandle(StepExecution managerStepExecution,
 		final Set<Future<StepExecution>> tasks = new HashSet<>(getGridSize());
 		final Set<StepExecution> result = new HashSet<>();
 
-		for (final StepExecution stepExecution : partitionStepExecutions) {
+		for (StepExecution stepExecution : partitionStepExecutions) {
 			final FutureTask<StepExecution> task = createTask(step, stepExecution);
 
 			try {
@@ -127,7 +127,7 @@ protected Set<StepExecution> doHandle(StepExecution managerStepExecution,
 	 * @param stepExecution the given execution
 	 * @return the task executing the given step
 	 */
-	protected FutureTask<StepExecution> createTask(final Step step, final StepExecution stepExecution) {
+	protected FutureTask<StepExecution> createTask(Step step, final StepExecution stepExecution) {
 		return new FutureTask<>(() -> {
 			step.execute(stepExecution);
 			return stepExecution;

spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/ExecutionContextDao.java

@@ -48,36 +48,36 @@ public interface ExecutionContextDao {
 	 * entry for the context should not exist yet.
 	 * @param jobExecution {@link JobExecution} instance that contains the context.
 	 */
-	void saveExecutionContext(final JobExecution jobExecution);
+	void saveExecutionContext(JobExecution jobExecution);
 
 	/**
 	 * Persist the execution context associated with the given stepExecution, persistent
 	 * entry for the context should not exist yet.
 	 * @param stepExecution {@link StepExecution} instance that contains the context.
 	 */
-	void saveExecutionContext(final StepExecution stepExecution);
+	void saveExecutionContext(StepExecution stepExecution);
 
 	/**
 	 * Persist the execution context associated with each stepExecution in a given
 	 * collection, persistent entry for the context should not exist yet.
 	 * @param stepExecutions a collection of {@link StepExecution}s that contain the
 	 * contexts.
 	 */
-	void saveExecutionContexts(final Collection<StepExecution> stepExecutions);
+	void saveExecutionContexts(Collection<StepExecution> stepExecutions);
 
 	/**
 	 * Persist the updates of execution context associated with the given jobExecution.
 	 * Persistent entry should already exist for this context.
 	 * @param jobExecution {@link JobExecution} instance that contains the context.
 	 */
-	void updateExecutionContext(final JobExecution jobExecution);
+	void updateExecutionContext(JobExecution jobExecution);
 
 	/**
 	 * Persist the updates of execution context associated with the given stepExecution.
 	 * Persistent entry should already exist for this context.
 	 * @param stepExecution {@link StepExecution} instance that contains the context.
 	 */
-	void updateExecutionContext(final StepExecution stepExecution);
+	void updateExecutionContext(StepExecution stepExecution);
 
 	/**
 	 * Delete the execution context of the given {@link JobExecution}.

spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/jdbc/JdbcExecutionContextDao.java

@@ -172,7 +172,7 @@ public ExecutionContext getExecutionContext(StepExecution stepExecution) {
 	}
 
 	@Override
-	public void updateExecutionContext(final JobExecution jobExecution) {
+	public void updateExecutionContext(JobExecution jobExecution) {
 		Long executionId = jobExecution.getId();
 		ExecutionContext executionContext = jobExecution.getExecutionContext();
 		Assert.notNull(executionId, "ExecutionId must not be null.");
@@ -184,7 +184,7 @@ public void updateExecutionContext(final JobExecution jobExecution) {
 	}
 
 	@Override
-	public void updateExecutionContext(final StepExecution stepExecution) {
+	public void updateExecutionContext(StepExecution stepExecution) {
 		// Attempt to prevent concurrent modification errors by blocking here if
 		// someone is already trying to do it.
 		this.lock.lock();
@@ -271,7 +271,7 @@ public void afterPropertiesSet() throws Exception {
 	 * @param serializedContext the serialized context to persist
 	 * @param sql with parameters (shortContext, longContext, executionId)
 	 */
-	private void persistSerializedContext(final Long executionId, String serializedContext, String sql) {
+	private void persistSerializedContext(Long executionId, String serializedContext, String sql) {
 
 		final String shortContext;
 		final String longContext;
@@ -302,7 +302,7 @@ private void persistSerializedContext(final Long executionId, String serializedC
 	 * @param serializedContexts the execution contexts to serialize
 	 * @param sql with parameters (shortContext, longContext, executionId)
 	 */
-	private void persistSerializedContexts(final Map<Long, String> serializedContexts, String sql) {
+	private void persistSerializedContexts(Map<Long, String> serializedContexts, String sql) {
 		if (!serializedContexts.isEmpty()) {
 			final Iterator<Long> executionIdIterator = serializedContexts.keySet().iterator();
 

spring-batch-core/src/main/java/org/springframework/batch/core/repository/dao/jdbc/JdbcJobExecutionDao.java

@@ -207,7 +207,7 @@ public void afterPropertiesSet() throws Exception {
 	}
 
 	@Override
-	public List<JobExecution> findJobExecutions(final JobInstance job) {
+	public List<JobExecution> findJobExecutions(JobInstance job) {
 
 		Assert.notNull(job, "Job cannot be null.");
 		Assert.notNull(job.getId(), "Job Id cannot be null.");