Add AbstractTaskletStepBuilder copy constructor

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
+	 */
+	public 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();
 
 	/**