Allow a Locale to be set for formatting

spring-batch-excel/README.adoc

@@ -1,4 +1,4 @@
-# spring-batch-excel
+= spring-batch-excel
 
 Spring Batch extension containing an `ItemReader` implementation for Excel based on https://poi.apache.org[Apache POI]. It supports reading both XLS and XLSX files. For the latter, there is also (experimental) streaming support.
 
@@ -8,26 +8,28 @@ To reduce the memory footprint the `StreamingXlsxItemReader` can be used, this w
 
 NOTE: The `ItemReader` classess are **not threadsafe**. The API from https://poi.apache.org/help/faq.html#20[Apache POI] itself isn't threadsafe as well as the https://docs.spring.io/spring-batch/docs/current/api/org/springframework/batch/item/support/AbstractItemCountingItemStreamItemReader.html[`AbstractItemCountingItemStreamItemReader`] used as a base class for the `ItemReader` classes. Reading from multiple threads is therefore not supported. Using a multi-threaded processor/writer should work as long as you use a single thread for reading.
 
-## Configuration of `PoiItemReader`
+== Configuration of `PoiItemReader`
 
 Next to the https://docs.spring.io/spring-batch/reference/html/configureJob.html[configuration of Spring Batch] one needs to configure the `PoiItemReader`.
 
 Configuration of can be done in XML or Java Config.
 
-### XML
+=== XML
 
-```xml
+[source,xml]
+----
  <bean id="excelReader" class="org.springframework.batch.extensions.excel.poi.PoiItemReader" scope="step">
      <property name="resource" value="file:/path/to/your/excel/file" />
      <property name="rowMapper">
          <bean class="org.springframework.batch.extensions.excel.mapping.PassThroughRowMapper" />
      </property>
  </bean>
-```
+----
 
-### Java Config
+=== Java Config
 
-```java
+[source,java]
+----
 @Bean
 @StepScope
 public PoiItemReader excelReader() {
@@ -41,43 +43,45 @@ public PoiItemReader excelReader() {
 public RowMapper rowMapper() {
     return new PassThroughRowMapper();
 }
-```
+----
 
-## Configuration of `StreamingXlsxItemReader`
+== Configuration of `StreamingXlsxItemReader`
 
 Configuration can be done in XML or Java Config.
 
-### XML
+=== XML
 
-```xml
+[source,xml]
+----
  <bean id="excelReader" class="org.springframework.batch.extensions.excel.streaming.StreamingXlsxItemReader" scope="step">
      <property name="resource" value="file:/path/to/your/excel/file" />
      <property name="rowMapper">
          <bean class="org.springframework.batch.extensions.excel.mapping.PassThroughRowMapper" />
      </property>
  </bean>
-```
+----
 
-### Java Config
+=== Java Config
 
-```java
+[source,java]
+----
 @Bean
 @StepScope
-public StreamingXlsxItemReader excelReader() {
+public StreamingXlsxItemReader excelReader(RowMapper rowMapper) {
     StreamingXlsxItemReader reader = new StreamingXlsxItemReader();
     reader.setResource(new FileSystemResource("/path/to/your/excel/file"));
-    reader.setRowMapper(rowMapper());
+    reader.setRowMapper(rowMapper);
     return reader;
 }
 
 @Bean
 public RowMapper rowMapper() {
     return new PassThroughRowMapper();
 }
-```
+----
 
 
-## Configuration properties
+== Configuration properties
 [cols="1,1,1,4"]
 .Properties for item readers
 |===
@@ -91,28 +95,30 @@ public RowMapper rowMapper() {
 | `rowSetFactory` | no | `DefaultRowSetFactory` | For reading rows a `RowSet` abstraction is used. To construct a `RowSet` for the current `Sheet` a `RowSetFactory` is needed. The `DefaultRowSetFactory` constructs a `DefaultRowSet` and `DefaultRowSetMetaData`. For construction of the latter a `ColumnNameExtractor` is needed. At the moment there are 2 implementations
 | `skippedRowsCallback` | no | `null` | When rows are skipped an optional `RowCallbackHandler` is called with the skipped row. This comes in handy when one needs to write the skipped rows to another file or create some logging.
 | `strict` | no | `true` | This controls wether or not an exception is thrown if the file doesn't exists or isn't readable, by default an exception will be thrown.
-| `datesAsIso` | no | `false` | Controls if dates need to be parsed as ISO or to use the format as specified in the excel sheet. *NOTE:* Only for the `PoiItemReader` **not** the `StreamingXlsxReader`!
+| `datesAsIso` | no | `false` | Controls if dates need to be parsed as ISO or to use the format as specified in the excel sheet.
+| `userLocale` | no | `null` | Set the `java.util.Locale` to use when formatting dates when there is no explicit format set in the Excel document.
 |===
 
- - `StaticColumnNameExtractor` uses a preset list of column names.
+- `StaticColumnNameExtractor` uses a preset list of column names.
  - `RowNumberColumnNameExtractor` (**the default**) reads a given row (default 0) to determine the column names of the current sheet
 
-## RowMappers
+== RowMappers
 To map a read row a `RowMapper` is needed. Out-of-the-box there are 2 implementations. The `PassThroughRowMapper` and `BeanWrapperRowMapper`.
 
-### PassThroughRowMapper
+=== PassThroughRowMapper
 Transforms the read row from excel into a `String[]`.
 
-### BeanWrapperRowMapper
+=== BeanWrapperRowMapper
 Uses a `BeanWrapper` to convert a given row into an object. Uses the column names of the given `RowSet` to map column to properties of the `targetType` or prototype bean.
 
-```java
+[source,xml]
+----
 <bean id="excelReader" class="org.springframework.batch.extensions.excel.poi.PoiItemReader" scope="step">
     <property name="resource" value="file:/path/to/your/excel/file" />
     <property name="rowMapper">
         <bean class="org.springframework.batch.extensions.excel.mapping.BeanWrapperRowMapper">
             <property name="targetType" value="com.your.package.Player" />
-        <bean>
+        </bean>
     </property>
 </bean>
-```
+----

spring-batch-excel/src/main/java/org/springframework/batch/extensions/excel/AbstractExcelItemReader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2021 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.
@@ -16,8 +16,11 @@
 
 package org.springframework.batch.extensions.excel;
 
+import java.util.Locale;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+import org.apache.poi.ss.usermodel.DataFormatter;
 
 import org.springframework.batch.extensions.excel.support.rowset.DefaultRowSetFactory;
 import org.springframework.batch.extensions.excel.support.rowset.RowSet;
@@ -65,6 +68,12 @@ public abstract class AbstractExcelItemReader<T> extends AbstractItemCountingIte
 
 	private String password;
 
+	private boolean datesAsIso = false;
+
+	private Locale userLocale;
+
+	private DataFormatter dataFormatter;
+
 	public AbstractExcelItemReader() {
 		super();
 		this.setName(ClassUtils.getShortName(this.getClass()));
@@ -213,6 +222,16 @@ public void setResource(final Resource resource) {
 
 	public void afterPropertiesSet() throws Exception {
 		Assert.notNull(this.rowMapper, "RowMapper must be set");
+		if (this.datesAsIso) {
+			this.dataFormatter = (this.userLocale != null) ? new IsoFormattingDateDataFormatter(this.userLocale) : new IsoFormattingDateDataFormatter();
+		}
+		else {
+			this.dataFormatter = (this.userLocale != null) ? new DataFormatter(this.userLocale) : new DataFormatter();
+		}
+	}
+
+	protected DataFormatter getDataFormatter() {
+		return this.dataFormatter;
 	}
 
 	/**
@@ -295,4 +314,20 @@ public void setPassword(String password) {
 		this.password = password;
 	}
 
+	/**
+	 * Instead of using the format defined in the Excel sheet, read the date/time fields as an ISO formatted
+	 * string instead. This is by default {@code false} to leave the original behavior.
+	 * @param datesAsIso default {@code false}
+	 */
+	public void setDatesAsIso(boolean datesAsIso) {
+		this.datesAsIso = datesAsIso;
+	}
+
+	/**
+	 * The {@code Locale} to use when reading sheets. Defaults to the platform default as set by Java.
+	 * @param userLocale the {@code Locale} to use, default {@code null}
+	 */
+	public void setUserLocale(Locale userLocale) {
+		this.userLocale = userLocale;
+	}
 }

spring-batch-excel/src/main/java/org/springframework/batch/extensions/excel/IsoFormattingDateDataFormatter.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2011-2022 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.extensions.excel;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.Locale;
+
+import org.apache.poi.ss.formula.ConditionalFormattingEvaluator;
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellType;
+import org.apache.poi.ss.usermodel.DataFormatter;
+import org.apache.poi.ss.usermodel.DateUtil;
+import org.apache.poi.ss.usermodel.FormulaEvaluator;
+
+/**
+ * Specialized subclass for additionally formatting the date into an ISO date/time.
+ *
+ * @author Marten Deinum
+ *
+ * @see DateTimeFormatter#ISO_OFFSET_DATE_TIME
+ */
+public class IsoFormattingDateDataFormatter extends DataFormatter {
+
+	public IsoFormattingDateDataFormatter() {
+		super();
+	}
+
+	public IsoFormattingDateDataFormatter(Locale locale) {
+		super(locale);
+	}
+
+	@Override
+	public String formatCellValue(Cell cell, FormulaEvaluator evaluator, ConditionalFormattingEvaluator cfEvaluator) {
+		if (cell == null) {
+			return "";
+		}
+
+		CellType cellType = cell.getCellType();
+		if (cellType == CellType.FORMULA) {
+			if (evaluator == null) {
+				return cell.getCellFormula();
+			}
+			cellType = evaluator.evaluateFormulaCell(cell);
+		}
+
+		if (cellType == CellType.NUMERIC && DateUtil.isCellDateFormatted(cell, cfEvaluator)) {
+			LocalDateTime value = cell.getLocalDateTimeCellValue();
+			return (value != null) ? value.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME) : "";
+		}
+		return super.formatCellValue(cell, evaluator, cfEvaluator);
+	}
+}

spring-batch-excel/src/main/java/org/springframework/batch/extensions/excel/poi/PoiItemReader.java

@@ -44,11 +44,9 @@ public class PoiItemReader<T> extends AbstractExcelItemReader<T> {
 
 	private InputStream inputStream;
 
-	private boolean datesAsIso = false;
-
 	@Override
 	protected Sheet getSheet(final int sheet) {
-		return new PoiSheet(this.workbook.getSheetAt(sheet), this.datesAsIso);
+		return new PoiSheet(this.workbook.getSheetAt(sheet), getDataFormatter());
 	}
 
 	@Override
@@ -92,12 +90,4 @@ protected void openExcelFile(final Resource resource, String password) throws Ex
 		this.workbook.setMissingCellPolicy(Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
 	}
 
-	/**
-	 * Instead of using the format defined in the Excel sheet, read the date/time fields as an ISO formatted
-	 * string instead. This is by default {@code false} to leave the original behavior.
-	 * @param datesAsIso default {@code false}
-	 */
-	public void setDatesAsIso(boolean datesAsIso) {
-		this.datesAsIso = datesAsIso;
-	}
 }

spring-batch-excel/src/main/java/org/springframework/batch/extensions/excel/poi/PoiSheet.java

@@ -16,17 +16,13 @@
 
 package org.springframework.batch.extensions.excel.poi;
 
-import java.time.LocalDateTime;
-import java.time.format.DateTimeFormatter;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 
-import org.apache.poi.ss.formula.ConditionalFormattingEvaluator;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.CellType;
 import org.apache.poi.ss.usermodel.DataFormatter;
-import org.apache.poi.ss.usermodel.DateUtil;
 import org.apache.poi.ss.usermodel.FormulaEvaluator;
 import org.apache.poi.ss.usermodel.Row;
 
@@ -42,28 +38,23 @@
 class PoiSheet implements Sheet {
 
 	private final DataFormatter dataFormatter;
-
 	private final org.apache.poi.ss.usermodel.Sheet delegate;
-	private final boolean datesAsIso;
-
 	private final int numberOfRows;
-
 	private final String name;
 
 	private FormulaEvaluator evaluator;
 
 	/**
 	 * Constructor which takes the delegate sheet.
 	 * @param delegate the apache POI sheet
-	 * @param datesAsIso should we format the dates as ISO or use the Excel formatting instead
+	 * @param dataFormatter the {@code DataFormatter} to use.
 	 */
-	PoiSheet(final org.apache.poi.ss.usermodel.Sheet delegate, boolean datesAsIso) {
+	PoiSheet(final org.apache.poi.ss.usermodel.Sheet delegate, DataFormatter dataFormatter) {
 		super();
 		this.delegate = delegate;
-		this.datesAsIso = datesAsIso;
 		this.numberOfRows = this.delegate.getLastRowNum() + 1;
 		this.name = this.delegate.getSheetName();
-		this.dataFormatter = this.datesAsIso ? new IsoFormattingDateDataFormatter() : new DataFormatter();
+		this.dataFormatter = dataFormatter;
 	}
 
 	/**
@@ -142,33 +133,4 @@ public String[] next() {
 		};
 	}
 
-	/**
-	 * Specialized subclass for additionally formatting the date into an ISO date/time.
-	 *
-	 * @author Marten Deinum
-	 * @see DateTimeFormatter#ISO_OFFSET_DATE_TIME
-	 */
-	private static class IsoFormattingDateDataFormatter extends DataFormatter {
-
-		@Override
-		public String formatCellValue(Cell cell, FormulaEvaluator evaluator, ConditionalFormattingEvaluator cfEvaluator) {
-			if (cell == null) {
-				return "";
-			}
-
-			CellType cellType = cell.getCellType();
-			if (cellType == CellType.FORMULA) {
-				if (evaluator == null) {
-					return cell.getCellFormula();
-				}
-				cellType = evaluator.evaluateFormulaCell(cell);
-			}
-
-			if (cellType == CellType.NUMERIC && DateUtil.isCellDateFormatted(cell, cfEvaluator)) {
-				LocalDateTime value = cell.getLocalDateTimeCellValue();
-				return (value != null) ? value.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME) : "";
-			}
-			return super.formatCellValue(cell, evaluator, cfEvaluator);
-		}
-	}
 }