Mark fields as final where appropriate

Author: fmbenhassine

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

@@ -36,11 +36,11 @@
  */
 public class JobParameter<T> implements Serializable {
 
-	private T value;
+	private final T value;
 
-	private Class<T> type;
+	private final Class<T> type;
 
-	private boolean identifying;
+	private final boolean identifying;
 
 	/**
 	 * Create a new {@link JobParameter}.

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

@@ -44,7 +44,7 @@ public class StepContribution implements Serializable {
 
 	private ExitStatus exitStatus = ExitStatus.EXECUTING;
 
-	private volatile StepExecution stepExecution;
+	private final StepExecution stepExecution;
 
 	/**
 	 * @param execution {@link StepExecution} the stepExecution used to initialize

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

@@ -52,7 +52,7 @@ public abstract class AbstractApplicationContextFactory implements ApplicationCo
 
 	private static final Log logger = LogFactory.getLog(AbstractApplicationContextFactory.class);
 
-	private Object[] resources;
+	private final Object[] resources;
 
 	private ConfigurableApplicationContext parent;
 

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

@@ -45,7 +45,7 @@
  */
 public class AutomaticJobRegistrar implements Ordered, SmartLifecycle, ApplicationContextAware, InitializingBean {
 
-	private Collection<ApplicationContextFactory> applicationContextFactories = new ArrayList<>();
+	private final Collection<ApplicationContextFactory> applicationContextFactories = new ArrayList<>();
 
 	private JobLoader jobLoader;
 
@@ -57,7 +57,7 @@ public class AutomaticJobRegistrar implements Ordered, SmartLifecycle, Applicati
 
 	private boolean autoStartup = true;
 
-	private Object lifecycleMonitor = new Object();
+	private final Object lifecycleMonitor = new Object();
 
 	private int order = Ordered.LOWEST_PRECEDENCE;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -50,15 +50,15 @@
  */
 public class DefaultJobLoader implements JobLoader, InitializingBean {
 
-	private static Log logger = LogFactory.getLog(DefaultJobLoader.class);
+	private static final Log logger = LogFactory.getLog(DefaultJobLoader.class);
 
 	private JobRegistry jobRegistry;
 
 	private StepRegistry stepRegistry;
 
-	private Map<ApplicationContextFactory, ConfigurableApplicationContext> contexts = new ConcurrentHashMap<>();
+	private final Map<ApplicationContextFactory, ConfigurableApplicationContext> contexts = new ConcurrentHashMap<>();
 
-	private Map<ConfigurableApplicationContext, Collection<String>> contextToJobNames = new ConcurrentHashMap<>();
+	private final Map<ConfigurableApplicationContext, Collection<String>> contextToJobNames = new ConcurrentHashMap<>();
 
 	/**
 	 * Default constructor. Useful for declarative configuration.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -31,7 +31,7 @@
  */
 public class JobFactoryRegistrationListener {
 
-	private Log logger = LogFactory.getLog(getClass());
+	private final Log logger = LogFactory.getLog(getClass());
 
 	private JobRegistry jobRegistry;
 

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

@@ -48,12 +48,12 @@
 public class JobRegistryBeanPostProcessor
 		implements BeanPostProcessor, BeanFactoryAware, InitializingBean, DisposableBean {
 
-	private static Log logger = LogFactory.getLog(JobRegistryBeanPostProcessor.class);
+	private static final Log logger = LogFactory.getLog(JobRegistryBeanPostProcessor.class);
 
 	// It doesn't make sense for this to have a default value...
 	private JobRegistry jobRegistry = null;
 
-	private Collection<String> jobNames = new HashSet<>();
+	private final Collection<String> jobNames = new HashSet<>();
 
 	private String groupName = null;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -27,7 +27,7 @@
  */
 public class ReferenceJobFactory implements JobFactory {
 
-	private Job job;
+	private final Job job;
 
 	/**
 	 * @param job the {@link Job} to return from {@link #createJob()}.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021-2022 the original author or authors.
+ * Copyright 2021-2023 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.
@@ -29,9 +29,9 @@
 @Configuration(proxyBeanMethods = false)
 public class ScopeConfiguration {
 
-	private static StepScope stepScope;
+	private static final StepScope stepScope;
 
-	private static JobScope jobScope;
+	private static final JobScope jobScope;
 
 	static {
 		jobScope = new JobScope();

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -37,7 +37,7 @@
  */
 public class JobParserJobFactoryBean implements SmartFactoryBean<FlowJob> {
 
-	private String name;
+	private final String name;
 
 	private Boolean restartable;
 

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

@@ -114,7 +114,7 @@ public class StepParserStepFactoryBean<I, O> implements FactoryBean<Step>, BeanN
 
 	private PlatformTransactionManager transactionManager;
 
-	private Set<Object> stepExecutionListeners = new LinkedHashSet<>();
+	private final Set<Object> stepExecutionListeners = new LinkedHashSet<>();
 
 	//
 	// Flow Elements
@@ -154,7 +154,7 @@ public class StepParserStepFactoryBean<I, O> implements FactoryBean<Step>, BeanN
 
 	private Isolation isolation;
 
-	private Set<ChunkListener> chunkListeners = new LinkedHashSet<>();
+	private final Set<ChunkListener> chunkListeners = new LinkedHashSet<>();
 
 	//
 	// Chunk Attributes
@@ -204,13 +204,13 @@ public class StepParserStepFactoryBean<I, O> implements FactoryBean<Step>, BeanN
 
 	private ItemStream[] streams;
 
-	private Set<ItemReadListener<I>> readListeners = new LinkedHashSet<>();
+	private final Set<ItemReadListener<I>> readListeners = new LinkedHashSet<>();
 
-	private Set<ItemWriteListener<O>> writeListeners = new LinkedHashSet<>();
+	private final Set<ItemWriteListener<O>> writeListeners = new LinkedHashSet<>();
 
-	private Set<ItemProcessListener<I, O>> processListeners = new LinkedHashSet<>();
+	private final Set<ItemProcessListener<I, O>> processListeners = new LinkedHashSet<>();
 
-	private Set<SkipListener<I, O>> skipListeners = new LinkedHashSet<>();
+	private final Set<SkipListener<I, O>> skipListeners = new LinkedHashSet<>();
 
 	//
 	// Additional

spring-batch-core/src/main/java/org/springframework/batch/core/explore/support/AbstractJobExplorerFactoryBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -54,7 +54,7 @@ public abstract class AbstractJobExplorerFactoryBean implements FactoryBean<JobE
 
 	private TransactionAttributeSource transactionAttributeSource;
 
-	private ProxyFactory proxyFactory = new ProxyFactory();
+	private final ProxyFactory proxyFactory = new ProxyFactory();
 
 	/**
 	 * Creates a job instance data access object (DAO).

spring-batch-core/src/main/java/org/springframework/batch/core/explore/support/JobExplorerFactoryBean.java

@@ -70,7 +70,7 @@ public class JobExplorerFactoryBean extends AbstractJobExplorerFactoryBean imple
 
 	private String tablePrefix = AbstractJdbcBatchMetadataDao.DEFAULT_TABLE_PREFIX;
 
-	private DataFieldMaxValueIncrementer incrementer = new AbstractDataFieldMaxValueIncrementer() {
+	private final DataFieldMaxValueIncrementer incrementer = new AbstractDataFieldMaxValueIncrementer() {
 		@Override
 		protected long getNextKey() {
 			throw new IllegalStateException("JobExplorer is read only.");

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

@@ -82,7 +82,7 @@ public abstract class AbstractJob implements Job, StepLocator, BeanNameAware, In
 
 	private JobRepository jobRepository;
 
-	private CompositeJobExecutionListener listener = new CompositeJobExecutionListener();
+	private final CompositeJobExecutionListener listener = new CompositeJobExecutionListener();
 
 	private JobParametersIncrementer jobParametersIncrementer;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2019 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -43,7 +43,7 @@
  */
 public class SimpleJob extends AbstractJob {
 
-	private List<Step> steps = new ArrayList<>();
+	private final List<Step> steps = new ArrayList<>();
 
 	/**
 	 * Default constructor for job with null name

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -47,27 +47,28 @@
  *
  * @author Dave Syer
  * @author Michael Minella
+ * @author Mahmoud Ben Hassine
  * @since 2.2
  * @param <Q> the type of object returned by the builder (by default a Flow)
  *
  */
 public class FlowBuilder<Q> {
 
-	private String name;
+	private final String name;
 
-	private String prefix;
+	private final String prefix;
 
-	private List<StateTransition> transitions = new ArrayList<>();
+	private final List<StateTransition> transitions = new ArrayList<>();
 
-	private Map<String, State> tos = new HashMap<>();
+	private final Map<String, State> tos = new HashMap<>();
 
 	private State currentState;
 
-	private EndState failedState;
+	private final EndState failedState;
 
-	private EndState completedState;
+	private final EndState completedState;
 
-	private EndState stoppedState;
+	private final EndState stoppedState;
 
 	private int stepCounter = 0;
 
@@ -79,7 +80,7 @@ public class FlowBuilder<Q> {
 
 	private int endCounter = 0;
 
-	private Map<Object, State> states = new HashMap<>();
+	private final Map<Object, State> states = new HashMap<>();
 
 	private SimpleFlow flow;
 
@@ -606,7 +607,7 @@ public static class SplitBuilder<Q> {
 
 		private final FlowBuilder<Q> parent;
 
-		private TaskExecutor executor;
+		private final TaskExecutor executor;
 
 		/**
 		 * @param parent the parent builder

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -22,11 +22,12 @@
 
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  *
  */
 public class JobFlowBuilder extends FlowBuilder<FlowJobBuilder> {
 
-	private FlowJobBuilder parent;
+	private final FlowJobBuilder parent;
 
 	public JobFlowBuilder(FlowJobBuilder parent) {
 		super(parent.getName());

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2013 the original author or authors.
+ * Copyright 2012-2023 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.
@@ -27,12 +27,13 @@
 
 /**
  * @author Dave Syer
+ * @author Mahmoud Ben Hassine
  * @since 2.2
  *
  */
 public class SimpleJobBuilder extends JobBuilderHelper<SimpleJobBuilder> {
 
-	private List<Step> steps = new ArrayList<>();
+	private final List<Step> steps = new ArrayList<>();
 
 	private JobFlowBuilder builder;
 

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

@@ -42,7 +42,7 @@ public class FlowJob extends AbstractJob {
 
 	protected Flow flow;
 
-	private Map<String, Step> stepMap = new ConcurrentHashMap<>();
+	private final Map<String, Step> stepMap = new ConcurrentHashMap<>();
 
 	private volatile boolean initialized = false;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 the original author or authors.
+ * Copyright 2006-2023 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.
@@ -56,9 +56,9 @@ public class SimpleFlow implements Flow, InitializingBean {
 
 	private State startState;
 
-	private Map<String, Set<StateTransition>> transitionMap = new HashMap<>();
+	private final Map<String, Set<StateTransition>> transitionMap = new HashMap<>();
 
-	private Map<String, State> stateMap = new HashMap<>();
+	private final Map<String, State> stateMap = new HashMap<>();
 
 	private List<StateTransition> stateTransitions = new ArrayList<>();
 

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

@@ -46,7 +46,7 @@ public class SplitState extends AbstractState implements FlowHolder {
 
 	private TaskExecutor taskExecutor = new SyncTaskExecutor();
 
-	private FlowExecutionAggregator aggregator = new MaxValueFlowExecutionAggregator();
+	private final FlowExecutionAggregator aggregator = new MaxValueFlowExecutionAggregator();
 
 	/**
 	 * @param flows collection of {@link Flow} instances.