Change default encoding to UTF-8 in file-based readers and writers

This commit overrides the fix in #3910 by using UTF-8
as default encoding in file-based item readers and writers.

Issue #1154

Author: fmbenhassine

spring-batch-docs/src/main/asciidoc/readersAndWriters.adoc

@@ -285,7 +285,7 @@ interpreted, as described in the following table:
 |===============
 |Property|Type|Description
 |comments|String[]|Specifies line prefixes that indicate comment rows.
-|encoding|String|Specifies what text encoding to use. The default is the value of `Charset.defaultCharset()`.
+|encoding|String|Specifies what text encoding to use. The default value is `UTF-8`.
 |lineMapper|`LineMapper`|Converts a `String` to an `Object` representing the item.
 |linesToSkip|int|Number of lines to ignore at the top of the file.
 |recordSeparatorPolicy|RecordSeparatorPolicy|Used to determine where the line endings are

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2020 the original author or authors.
+ * Copyright 2006-2022 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.
@@ -19,6 +19,7 @@
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -48,8 +49,7 @@ public class FlatFileItemReader<T> extends AbstractItemCountingItemStreamItemRea
 
 	private static final Log logger = LogFactory.getLog(FlatFileItemReader.class);
 
-	// default encoding for input files
-	public static final String DEFAULT_CHARSET = Charset.defaultCharset().name();
+	public static final String DEFAULT_CHARSET = StandardCharsets.UTF_8.name();
 
 	public static final String[] DEFAULT_COMMENT_PREFIXES = new String[] { "#" };
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/support/AbstractFileItemWriter.java

@@ -24,6 +24,7 @@
 import java.nio.channels.Channels;
 import java.nio.channels.FileChannel;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.charset.UnsupportedCharsetException;
 import java.util.List;
 
@@ -74,8 +75,7 @@ public abstract class AbstractFileItemWriter<T> extends AbstractItemStreamItemWr
 
 	public static final String DEFAULT_LINE_SEPARATOR = System.getProperty("line.separator");
 
-	// default encoding for writing to flat files - set to charset of this Java virtual machine.
-	public static final String DEFAULT_CHARSET = Charset.defaultCharset().name();
+	public static final String DEFAULT_CHARSET = StandardCharsets.UTF_8.name();
 
 	private static final String WRITTEN_STATISTICS_NAME = "written";
 

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/xml/StaxEventItemReader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2020 the original author or authors.
+ * Copyright 2006-2022 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.
@@ -19,6 +19,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.NoSuchElementException;
@@ -64,7 +65,7 @@ public class StaxEventItemReader<T> extends AbstractItemCountingItemStreamItemRe
 
 	private static final Log logger = LogFactory.getLog(StaxEventItemReader.class);
 
-	public static final String DEFAULT_ENCODING = Charset.defaultCharset().name();
+	public static final String DEFAULT_ENCODING = StandardCharsets.UTF_8.name();
 
 	private FragmentEventReader fragmentReader;