Open FlatFileItemReader#isComment for extension

Resolves #1134

Author: fmbenhassine

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2019 the original author or authors.
+ * Copyright 2006-2020 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.
@@ -61,7 +61,7 @@ public class FlatFileItemReader<T> extends AbstractItemCountingItemStreamItemRea
 
 	private int lineCount = 0;
 
-	private String[] comments = DEFAULT_COMMENT_PREFIXES;
+	protected String[] comments = DEFAULT_COMMENT_PREFIXES;
 
 	private boolean noInput = false;
 
@@ -229,7 +229,7 @@ private String readLine() {
 		return line;
 	}
 
-	private boolean isComment(String line) {
+	protected boolean isComment(String line) {
 		for (String prefix : comments) {
 			if (line.startsWith(prefix)) {
 				return true;

spring-batch-infrastructure/src/test/java/org/springframework/batch/item/file/FlatFileItemReaderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2019 the original author or authors.
+ * Copyright 2008-2020 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.
@@ -215,6 +215,25 @@ public String preProcess(String record) {
 
 	}
 
+	@Test
+	public void testCustomCommentDetectionLogic() throws Exception {
+		reader = new FlatFileItemReader<String>() {
+			@Override
+			protected boolean isComment(String line) {
+				return super.isComment(line) || line.endsWith("2");
+			}
+		};
+		reader.setResource(getInputResource("#testLine1\ntestLine2\n//testLine3\ntestLine4\n"));
+		reader.setComments(new String[] {"#", "//"});
+		reader.setLineMapper(new PassThroughLineMapper());
+		reader.open(executionContext);
+
+		assertEquals("testLine4", reader.read());
+		assertNull(reader.read());
+
+		reader.close();
+	}
+
 	@Test
 	public void testRestartWithSkippedLines() throws Exception {