Use Spring Framework's CollectionUtils to create HashSet/HashMap

It handles initial capacity correctly.

Signed-off-by: Yanming Zhou <[email protected]>

Author: quaff

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

@@ -24,6 +24,7 @@
 import org.springframework.batch.infrastructure.item.ExecutionContext;
 import org.springframework.core.io.Resource;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Implementation of {@link Partitioner} that locates multiple resources and associates
@@ -70,7 +71,7 @@ public void setKeyName(String keyName) {
 	 */
 	@Override
 	public Map<String, ExecutionContext> partition(int gridSize) {
-		Map<String, ExecutionContext> map = new HashMap<>(gridSize);
+		Map<String, ExecutionContext> map = CollectionUtils.newHashMap(gridSize);
 		int i = 0;
 		for (Resource resource : resources) {
 			ExecutionContext context = new ExecutionContext();

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

@@ -21,6 +21,7 @@
 
 import org.springframework.batch.core.partition.Partitioner;
 import org.springframework.batch.infrastructure.item.ExecutionContext;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Simplest possible implementation of {@link Partitioner}. Just creates a set of empty
@@ -37,7 +38,7 @@ public class SimplePartitioner implements Partitioner {
 
 	@Override
 	public Map<String, ExecutionContext> partition(int gridSize) {
-		Map<String, ExecutionContext> map = new HashMap<>(gridSize);
+		Map<String, ExecutionContext> map = CollectionUtils.newHashMap(gridSize);
 		for (int i = 0; i < gridSize; i++) {
 			map.put(PARTITION_KEY + i, new ExecutionContext());
 		}

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

@@ -33,6 +33,7 @@
 import org.springframework.batch.core.partition.StepExecutionSplitter;
 import org.springframework.batch.core.repository.JobRepository;
 import org.springframework.batch.infrastructure.item.ExecutionContext;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Generic implementation of {@link StepExecutionSplitter} that delegates to a
@@ -128,7 +129,7 @@ public Set<StepExecution> split(StepExecution stepExecution, int gridSize) throw
 		JobExecution jobExecution = stepExecution.getJobExecution();
 
 		Map<String, ExecutionContext> contexts = getContexts(stepExecution, gridSize);
-		Set<StepExecution> set = new HashSet<>(contexts.size());
+		Set<StepExecution> set = CollectionUtils.newHashSet(contexts.size());
 
 		for (Entry<String, ExecutionContext> context : contexts.entrySet()) {
 
@@ -153,7 +154,7 @@ && shouldStart(allowStartIfComplete, stepExecution, lastStepExecution)) {
 			}
 		}
 
-		Set<StepExecution> executions = new HashSet<>(set.size());
+		Set<StepExecution> executions = CollectionUtils.newHashSet(set.size());
 		executions.addAll(set);
 
 		return executions;

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

@@ -34,6 +34,7 @@
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.core.task.TaskRejectedException;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 
 /**
  * A {@link PartitionHandler} that uses a {@link TaskExecutor} to execute the partitioned
@@ -94,8 +95,8 @@ public Step getStep() {
 	protected Set<StepExecution> doHandle(StepExecution managerStepExecution,
 			Set<StepExecution> partitionStepExecutions) throws Exception {
 		Assert.notNull(step, "A Step must be provided.");
-		final Set<Future<StepExecution>> tasks = new HashSet<>(getGridSize());
-		final Set<StepExecution> result = new HashSet<>();
+		final Set<Future<StepExecution>> tasks = CollectionUtils.newHashSet(partitionStepExecutions.size());
+		final Set<StepExecution> result = CollectionUtils.newHashSet(partitionStepExecutions.size());
 
 		for (StepExecution stepExecution : partitionStepExecutions) {
 			final FutureTask<StepExecution> task = createTask(step, stepExecution);

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

@@ -45,6 +45,7 @@
 import org.springframework.jdbc.core.BatchPreparedStatementSetter;
 import org.springframework.jdbc.core.RowMapper;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 
 /**
  * JDBC DAO for {@link ExecutionContext}.
@@ -238,7 +239,7 @@ public void saveExecutionContext(StepExecution stepExecution) {
 	@Override
 	public void saveExecutionContexts(Collection<StepExecution> stepExecutions) {
 		Assert.notNull(stepExecutions, "Attempt to save an null collection of step executions");
-		Map<Long, String> serializedContexts = new HashMap<>(stepExecutions.size());
+		Map<Long, String> serializedContexts = CollectionUtils.newHashMap(stepExecutions.size());
 		for (StepExecution stepExecution : stepExecutions) {
 			Long executionId = stepExecution.getId();
 			ExecutionContext executionContext = stepExecution.getExecutionContext();

spring-batch-infrastructure/src/main/java/org/springframework/batch/infrastructure/item/file/builder/FlatFileItemReaderBuilder.java

@@ -52,6 +52,7 @@
 import org.springframework.core.io.ByteArrayResource;
 import org.springframework.core.io.Resource;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -691,7 +692,7 @@ public DelimitedLineTokenizer build() {
 			}
 
 			if (!this.includedFields.isEmpty()) {
-				Set<Integer> deDupedFields = new HashSet<>(this.includedFields.size());
+				Set<Integer> deDupedFields = CollectionUtils.newHashSet(this.includedFields.size());
 				deDupedFields.addAll(this.includedFields);
 				deDupedFields.remove(null);
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/infrastructure/item/file/transform/DefaultFieldSet.java

@@ -35,6 +35,7 @@
 
 import org.jspecify.annotations.NullUnmarked;
 import org.jspecify.annotations.Nullable;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -131,7 +132,7 @@ public DefaultFieldSet(@Nullable String[] tokens, String[] names, @Nullable Date
 		}
 		this.tokens = tokens.clone();
 		this.names = Arrays.asList(names);
-		this.nameIndexMap = new HashMap<>(names.length);
+		this.nameIndexMap = CollectionUtils.newHashMap(names.length);
 		for (int i = 0; i < names.length; i++) {
 			this.nameIndexMap.put(names[i], i);
 		}

spring-batch-samples/src/main/java/org/springframework/batch/samples/loom/JobConfigurationForRunningPartitionedStepsWithVirtualThreads.java

@@ -37,6 +37,7 @@
 import org.springframework.context.annotation.Import;
 import org.springframework.core.task.VirtualThreadTaskExecutor;
 import org.springframework.jdbc.support.JdbcTransactionManager;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Configuration class that defines a partitioned step based on a
@@ -76,7 +77,7 @@ public Tasklet tasklet(@Value("#{stepExecutionContext['data']}") String partitio
 	@Bean
 	public Partitioner partitioner() {
 		return gridSize -> {
-			Map<String, ExecutionContext> partitionMap = new HashMap<>(gridSize);
+			Map<String, ExecutionContext> partitionMap = CollectionUtils.newHashMap(gridSize);
 			for (int i = 0; i < gridSize; i++) {
 				ExecutionContext executionContext = new ExecutionContext();
 				executionContext.put("data", "data" + i);