Migrate to JSpecify annotations for nullability constraints

pom.xml

@@ -156,6 +156,7 @@
 		<maven-jar-plugin.version>3.4.2</maven-jar-plugin.version>
 		<spring-javaformat-maven-plugin.version>0.0.47</spring-javaformat-maven-plugin.version>
 		<error-prone.version>2.38.0</error-prone.version>
+		<nullaway.version>0.12.7</nullaway.version>
 	</properties>
 
 	<build>
@@ -187,45 +188,10 @@
 						<compilerArg>--should-stop=ifError=FLOW</compilerArg>
 						<compilerArg>
 							-Xplugin:ErrorProne
-							-Xep:AlmostJavadoc:OFF
-							-Xep:ByteBufferBackingArray:OFF
-							-Xep:ClassCanBeStatic:OFF
-							-Xep:CollectionUndefinedEquality:OFF
-							-Xep:DefaultCharset:OFF
-							-Xep:DirectInvocationOnMock:OFF
-							-Xep:DoNotCallSuggester:OFF
-							-Xep:EmptyCatch:OFF
-							-Xep:EqualsGetClass:OFF
-							-Xep:Finally:OFF
-							-Xep:FutureReturnValueIgnored:OFF
-							-Xep:HidingField:OFF
-							-Xep:ImmutableEnumChecker:OFF
-							-Xep:InlineMeSuggester:OFF
-							-Xep:InputStreamSlowMultibyteRead:OFF
-							-Xep:JavaTimeDefaultTimeZone:OFF
-							-Xep:JavaUtilDate:OFF
-							-Xep:JdkObsolete:OFF
-							-Xep:MissingSummary:OFF
-							-Xep:MixedMutabilityReturnType:OFF
-							-Xep:MutablePublicArray:OFF
-							-Xep:NonAtomicVolatileUpdate:OFF
-							-Xep:RedundantControlFlow:OFF
-							-Xep:ReferenceEquality:OFF
-							-Xep:StaticAssignmentInConstructor:OFF
-							-Xep:StaticAssignmentOfThrowable:OFF
-							-Xep:StaticMockMember:OFF
-							-Xep:StreamResourceLeak:OFF
-							-Xep:StringCaseLocaleUsage:OFF
-							-Xep:StringSplitter:OFF
-							-Xep:SynchronizeOnNonFinalField:OFF
-							-Xep:ThreadLocalUsage:OFF
-							-Xep:ThreadPriorityCheck:OFF
-							-Xep:TypeParameterUnusedInFormals:OFF
-							-Xep:UndefinedEquals:OFF
-							-Xep:UnnecessaryStringBuilder:OFF
-							-Xep:UnusedMethod:OFF
-							-Xep:UnusedVariable:OFF
-							-Xep:WaitNotInLoop:OFF
+							<!-- Check JSpecify annotations -->
+							-Xep:NullAway:ERROR
+							-XepOpt:NullAway:OnlyNullMarked
+							-XepOpt:NullAway:CustomContractAnnotations=org.springframework.lang.Contract
 						</compilerArg>
 					</compilerArgs>
 					<annotationProcessorPaths>
@@ -234,6 +200,11 @@
 							<artifactId>error_prone_core</artifactId>
 							<version>${error-prone.version}</version>
 						</path>
+						<path>
+							<groupId>com.uber.nullaway</groupId>
+							<artifactId>nullaway</artifactId>
+							<version>${nullaway.version}</version>
+						</path>
 					</annotationProcessorPaths>
 				</configuration>
 			</plugin>

spring-batch-core/src/main/java/org/springframework/batch/core/SpringBatchVersion.java

@@ -15,7 +15,7 @@
  */
 package org.springframework.batch.core;
 
-import org.springframework.lang.Nullable;
+import org.jspecify.annotations.Nullable;
 
 /**
  * Class that exposes the Spring Batch version. Fetches the "Implementation-Version"
@@ -43,8 +43,7 @@ private SpringBatchVersion() {
 	 * {@code "N/A"} if it cannot be determined.
 	 * @see Package#getImplementationVersion()
 	 */
-	@Nullable
-	public static String getVersion() {
+	public static @Nullable String getVersion() {
 		Package pkg = SpringBatchVersion.class.getPackage();
 		if (pkg != null && pkg.getImplementationVersion() != null) {
 			return pkg.getImplementationVersion();

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

@@ -15,9 +15,10 @@
  */
 package org.springframework.batch.core.configuration;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.batch.core.job.Job;
 import org.springframework.batch.core.launch.NoSuchJobException;
-import org.springframework.lang.Nullable;
 
 /**
  * A runtime service locator interface for retrieving job configurations by

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/annotation/package-info.java

@@ -4,7 +4,7 @@
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
  */
-@NonNullApi
+@NullMarked
 package org.springframework.batch.core.configuration.annotation;
 
-import org.springframework.lang.NonNullApi;
+import org.jspecify.annotations.NullMarked;

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/package-info.java

@@ -4,7 +4,7 @@
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
  */
-@NonNullApi
+@NullMarked
 package org.springframework.batch.core.configuration;
 
-import org.springframework.lang.NonNullApi;
+import org.jspecify.annotations.NullMarked;

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

@@ -23,6 +23,7 @@
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.batch.core.job.Job;
 import org.springframework.batch.core.step.Step;
@@ -34,7 +35,6 @@
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -222,9 +222,9 @@ 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) {
-		final Collection<String> stepNames = stepLocator.getStepNames();
-		final Collection<Step> result = new ArrayList<>();
+	private Collection<Step> getSteps(StepLocator stepLocator, ApplicationContext jobApplicationContext) {
+		Collection<String> stepNames = stepLocator.getStepNames();
+		Collection<Step> result = new ArrayList<>();
 		for (String stepName : stepNames) {
 			result.add(stepLocator.getStep(stepName));
 		}
@@ -234,7 +234,7 @@ private Collection<Step> getSteps(final StepLocator stepLocator, final Applicati
 		// are more Step instances defined. Right now they are registered as being
 		// available in the
 		// context of the job but we have no idea if they are linked to that Job or not.
-		final Map<String, Step> allSteps = jobApplicationContext.getBeansOfType(Step.class);
+		Map<String, Step> allSteps = jobApplicationContext.getBeansOfType(Step.class);
 		for (Map.Entry<String, Step> entry : allSteps.entrySet()) {
 			if (!stepNames.contains(entry.getKey())) {
 				result.add(entry.getValue());

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

@@ -15,11 +15,12 @@
  */
 package org.springframework.batch.core.configuration.support;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.batch.core.job.Job;
 import org.springframework.batch.core.job.JobExecution;
 import org.springframework.batch.core.job.parameters.JobParametersIncrementer;
 import org.springframework.batch.core.job.parameters.JobParametersValidator;
-import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
 
 /**
@@ -87,8 +88,7 @@ public boolean isRestartable() {
 	}
 
 	@Override
-	@Nullable
-	public JobParametersIncrementer getJobParametersIncrementer() {
+	public @Nullable JobParametersIncrementer getJobParametersIncrementer() {
 		return delegate.getJobParametersIncrementer();
 	}
 

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

@@ -23,6 +23,8 @@
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.batch.core.job.Job;
 import org.springframework.batch.core.configuration.DuplicateJobException;
 import org.springframework.batch.core.configuration.JobRegistry;
@@ -31,7 +33,6 @@
 import org.springframework.beans.factory.SmartInitializingSingleton;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
-import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**

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

@@ -22,6 +22,8 @@
 import java.util.concurrent.ConcurrentMap;
 
 import org.springframework.batch.core.step.Step;
+
+import org.jspecify.annotations.Nullable;
 import org.springframework.batch.core.configuration.DuplicateJobException;
 import org.springframework.batch.core.configuration.StepRegistry;
 import org.springframework.batch.core.launch.NoSuchJobException;
@@ -62,7 +64,7 @@ public void unregisterStepsFromJob(String jobName) {
 	}
 
 	@Override
-	public Step getStep(String jobName, String stepName) throws NoSuchJobException {
+	public @Nullable Step getStep(String jobName, String stepName) throws NoSuchJobException {
 		Assert.notNull(jobName, "The job name cannot be null.");
 		Assert.notNull(stepName, "The step name cannot be null.");
 		if (!map.containsKey(jobName)) {

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

@@ -4,7 +4,7 @@
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
  */
-@NonNullApi
+@NullMarked
 package org.springframework.batch.core.configuration.support;
 
-import org.springframework.lang.NonNullApi;
+import org.jspecify.annotations.NullMarked;

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/xml/ExceptionElementParser.java

@@ -22,11 +22,13 @@
 import org.springframework.beans.factory.support.ManagedMap;
 import org.springframework.beans.factory.xml.ParserContext;
 import org.springframework.util.xml.DomUtils;
+
+import org.jspecify.annotations.Nullable;
 import org.w3c.dom.Element;
 
 public class ExceptionElementParser {
 
-	public ManagedMap<TypedStringValue, Boolean> parse(Element element, ParserContext parserContext,
+	public @Nullable ManagedMap<TypedStringValue, Boolean> parse(Element element, ParserContext parserContext,
 			String exceptionListName) {
 		List<Element> children = DomUtils.getChildElementsByTagName(element, exceptionListName);
 		if (children.size() == 1) {

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/xml/JobParser.java

@@ -30,6 +30,8 @@
 import org.springframework.beans.factory.xml.ParserContext;
 import org.springframework.util.StringUtils;
 import org.springframework.util.xml.DomUtils;
+
+import org.jspecify.annotations.Nullable;
 import org.w3c.dom.Element;
 
 /**
@@ -158,7 +160,7 @@ else if (listenersElements.size() > 1) {
 	 * @param parserContext The {@link ParserContext}.
 	 * @return the {@link BeanMetadataElement} extracted from the element parameter.
 	 */
-	public BeanMetadataElement parseBeanElement(Element element, ParserContext parserContext) {
+	public @Nullable BeanMetadataElement parseBeanElement(Element element, ParserContext parserContext) {
 		String refAttribute = element.getAttribute(REF_ATTR);
 		Element beanElement = DomUtils.getChildElementByTagName(element, BEAN_ELE);
 		Element refElement = DomUtils.getChildElementByTagName(element, REF_ELE);

spring-batch-core/src/main/java/org/springframework/batch/core/configuration/xml/package-info.java

@@ -4,7 +4,7 @@
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
  */
-@NonNullApi
+@NullMarked
 package org.springframework.batch.core.configuration.xml;
 
-import org.springframework.lang.NonNullApi;
+import org.jspecify.annotations.NullMarked;

spring-batch-core/src/main/java/org/springframework/batch/core/converter/DefaultJobParametersConverter.java

@@ -20,12 +20,12 @@
 import java.util.Properties;
 
 import org.springframework.batch.core.job.parameters.JobParameter;
+
+import org.jspecify.annotations.Nullable;
 import org.springframework.batch.core.job.parameters.JobParameters;
 import org.springframework.batch.core.job.parameters.JobParametersBuilder;
 import org.springframework.core.convert.support.ConfigurableConversionService;
 import org.springframework.core.convert.support.DefaultConversionService;
-import org.springframework.lang.NonNull;
-import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
@@ -131,7 +131,7 @@ public Properties getProperties(@Nullable JobParameters jobParameters) {
 	 * @param conversionService the conversion service to use. Must not be {@code null}.
 	 * @since 5.0
 	 */
-	public void setConversionService(@NonNull ConfigurableConversionService conversionService) {
+	public void setConversionService(ConfigurableConversionService conversionService) {
 		Assert.notNull(conversionService, "The conversionService must not be null");
 		this.conversionService = conversionService;
 	}

spring-batch-core/src/main/java/org/springframework/batch/core/converter/JobParametersConverter.java

@@ -21,6 +21,10 @@
 import org.springframework.batch.core.job.parameters.JobParameters;
 import org.springframework.batch.core.job.parameters.JobParametersBuilder;
 import org.springframework.lang.Nullable;
+import org.springframework.batch.core.JobParameters;
+
+import org.jspecify.annotations.Nullable;
+import org.springframework.batch.core.JobParametersBuilder;
 
 /**
  * A factory for {@link JobParameters} instances. A job can be executed with many possible

spring-batch-core/src/main/java/org/springframework/batch/core/converter/package-info.java

@@ -5,7 +5,7 @@
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
  */
-@NonNullApi
+@NullMarked
 package org.springframework.batch.core.converter;
 
-import org.springframework.lang.NonNullApi;
+import org.jspecify.annotations.NullMarked;

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

@@ -29,6 +29,7 @@
 import io.micrometer.observation.ObservationRegistry;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.batch.core.BatchStatus;
 import org.springframework.batch.core.ExitStatus;
@@ -54,7 +55,6 @@
 import org.springframework.batch.repeat.RepeatException;
 import org.springframework.beans.factory.BeanNameAware;
 import org.springframework.beans.factory.InitializingBean;
-import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -206,8 +206,7 @@ public void setJobParametersIncrementer(JobParametersIncrementer jobParametersIn
 	}
 
 	@Override
-	@Nullable
-	public JobParametersIncrementer getJobParametersIncrementer() {
+	public @Nullable JobParametersIncrementer getJobParametersIncrementer() {
 		return this.jobParametersIncrementer;
 	}
 

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

@@ -19,6 +19,9 @@
 import org.springframework.batch.core.job.parameters.JobParametersIncrementer;
 import org.springframework.batch.core.job.parameters.JobParametersValidator;
 import org.springframework.lang.Nullable;
+import org.jspecify.annotations.Nullable;
+
+import org.springframework.batch.core.job.DefaultJobParametersValidator;
 
 /**
  * Batch domain object representing a job. {@code Job} is an explicit abstraction
@@ -57,8 +60,7 @@ default boolean isRestartable() {
 	 * @return an incrementer to be used for creating new parameters. Defaults to
 	 * {@code null}.
 	 */
-	@Nullable
-	default JobParametersIncrementer getJobParametersIncrementer() {
+	default @Nullable JobParametersIncrementer getJobParametersIncrementer() {
 		return null;
 	}