README.adoc

spring-batch-excel

The code for this project is now part of the Spring Batch Extensions project and is thus no longer activily maintained here. Please redirect issues and likes to that repository.

Spring Batch extension which contains an ItemReader implementation for Excel based on Apache POI. It supports reading both XLS and XLSX files, for the latter there is also (experimental) streaming support.

The PoiItemReader has the most features but is also the most memory intensive and might lead to memory issues with large XLS(X) sheets.

To reduce the memory footprint the StreamingXlsxItemReader can be used, this will only keep the current row in memory and discard it afterwards. Not everything is supported while streaming the XLSX file, it can be that formulas don’t get evaluated or lead to an error.

Configuration of PoiItemReader

Next to the configuration of Spring Batch one needs to configure the PoiItemReader.

Configuration of can be done in XML or Java Config.

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

@Bean
@StepScope
public PoiItemReader excelReader() {
    PoiItemReader reader = new PoiItemReader();
    reader.setResource(new FileSystemResource("/path/to/your/excel/file"));
    reader.setRowMapper(rowMapper());
    return reader;
}

@Bean
public RowMapper rowMapper() {
    return new PassThroughRowMapper();
}

Configuration of StreamingXlsxItemReader

Configuration can be done in XML or Java Config.

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

@Bean
@StepScope
public StreamingXlsxItemReader excelReader() {
    StreamingXlsxItemReader reader = new StreamingXlsxItemReader();
    reader.setResource(new FileSystemResource("/path/to/your/excel/file"));
    reader.setRowMapper(rowMapper());
    return reader;
}

@Bean
public RowMapper rowMapper() {
    return new PassThroughRowMapper();
}

Configuration properties

Table 1. Properties for item readers

Property	Required	Default	Description
endAfterBlankLines	no	1	The number of blank lines before stopping to read.
linesToSkip	no	0	The number of lines to skip, this applies to each sheet in the Excel file, can be useful if the first couple of lines provide header information.
password	no	null	The password used to protect an XLS file. Only works for XLS files not XLSX files (not supported with streaming).
resource	yes	null	Location of the excel file to read, can be any resource supported by Spring.
rowMapper	yes	null	transforms the rows read from the sheet(s) to an object which you can use in the rest of the process.
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.

• 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

To map a read row a RowMapper is needed. Out-of-the-box there are 2 implementations. The PassThroughRowMapper and BeanWrapperRowMapper.

PassThroughRowMapper

Transforms the read row from excel into a String[].

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.

<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>
    </property>
</bean>