Add AbstractTaskletStepBuilder copy constructor and testcode

This commit includes tests for the copy constructor of AbstractTaskletStepBuilder and for the faultTolerant method, specifically after taskExecutor has been set.

Author: ilpyoyang

spring-batch-core/src/main/java/org/springframework/batch/core/step/builder/AbstractTaskletStepBuilder.java

@@ -49,6 +49,7 @@
  * @author Dave Syer
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
+ * @author Ilpyo Yang
  * @since 2.2
  * @param <B> the type of builder represented
  */
@@ -74,6 +75,23 @@ public AbstractTaskletStepBuilder(StepBuilderHelper<?> parent) {
 		super(parent);
 	}
 
+	/**
+	 * Create a new builder initialized with any properties in the parent. The parent is
+	 * copied, so it can be re-used.
+	 * @param parent a parent helper containing common step properties
+	 */
+	protected AbstractTaskletStepBuilder(AbstractTaskletStepBuilder<?> parent) {
+		super(parent);
+		this.chunkListeners = parent.chunkListeners;
+		this.stepOperations = parent.stepOperations;
+		this.transactionManager = parent.transactionManager;
+		this.transactionAttribute = parent.transactionAttribute;
+		this.streams.addAll(parent.streams);
+		this.exceptionHandler = parent.exceptionHandler;
+		this.throttleLimit = parent.throttleLimit;
+		this.taskExecutor = parent.taskExecutor;
+	}
+
 	protected abstract Tasklet createTasklet();
 
 	/**

spring-batch-core/src/test/java/org/springframework/batch/core/step/builder/AbstractTaskletStepBuilderTests.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright 2020-2022 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
+ *
+ *       https://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.step.builder;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.mock;
+
+import org.junit.jupiter.api.Test;
+import org.junit.platform.commons.util.ReflectionUtils;
+import org.springframework.batch.core.repository.JobRepository;
+import org.springframework.batch.core.step.tasklet.TaskletStep;
+import org.springframework.batch.item.ItemProcessor;
+import org.springframework.batch.item.ItemReader;
+import org.springframework.batch.item.ItemWriter;
+import org.springframework.batch.repeat.support.RepeatTemplate;
+import org.springframework.core.task.SimpleAsyncTaskExecutor;
+import org.springframework.transaction.PlatformTransactionManager;
+
+/**
+ * Test cases for verifying the {@link AbstractTaskletStepBuilder} and faultTolerant() functionality.
+ *
+ * @author Jérôme Navez
+ * @author Ilpyo Yang
+ */
+
+class AbstractTaskletStepBuilderTests {
+	private final PlatformTransactionManager transactionManager = mock(PlatformTransactionManager.class);
+	private final JobRepository jobRepository =  mock(JobRepository.class);
+	private final ItemReader itemReader = mock(ItemReader.class);
+	private final ItemProcessor itemProcessor = mock(ItemProcessor.class);
+	private final ItemWriter itemWriter = mock(ItemWriter.class);
+
+	private final SimpleAsyncTaskExecutor taskExecutor  = new SimpleAsyncTaskExecutor();
+
+	@Test
+	void testCopyConstractorFaultTolerant() {
+		TaskletStep step1 = new StepBuilder("step-name", jobRepository)
+				.chunk(10, transactionManager)
+				.reader(itemReader)
+				.processor(itemProcessor)
+				.writer(itemWriter)
+				.faultTolerant()
+				.taskExecutor(taskExecutor)
+				.build();
+
+		TaskletStep step2 = new StepBuilder("step-name", jobRepository)
+				.chunk(10, transactionManager)
+				.taskExecutor(taskExecutor)
+				.reader(itemReader)
+				.processor(itemProcessor)
+				.writer(itemWriter)
+				.faultTolerant()
+				.build();
+
+		RepeatTemplate stepOperations1 = (RepeatTemplate) ReflectionUtils
+				.readFieldValue(TaskletStep.class, "stepOperations", step1).get();
+		RepeatTemplate stepOperations2 = (RepeatTemplate) ReflectionUtils
+				.readFieldValue(TaskletStep.class, "stepOperations", step2).get();
+
+		assertEquals(stepOperations1.getClass(), stepOperations2.getClass());
+	}
+}