How to pass delimiter dynamically to spring DelimitedLineTokenizer

In spring batch, if the user wants to decide a Delimiter at run time based on the certain criteria. Built-in spring batch Tokenizer classes won’t support this feature. If we use our own customized class instead of using spring provided Tokenizer class, spring batch throws an error.

Actual Configuration:

<bean id="defaultTokenizer" class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">             <property name="delimiter" value="," /> </bean> <bean id="fieldSetMapper" class="com.mapper.CustomDataUploadFieldSetMapper" /> <bean id="defaultLineMapper" class="org.springframework.batch.item.file.mapping.DefaultLineMapper">             <property name="lineTokenizer" ref="defaultTokenizer"></property>             <property name="fieldSetMapper" ref="fieldSetMapper"></property> </bean> <bean id="customDataItemReader" class="com.reader.CustomDataLoadReader" scope="prototype">             <property name="lineMapper" ref="defaultLineMapper"></property> </bean>

Here, if we provide overridden Tokenizer instead of DelimitedLineTokenizer, spring container will throw an error while server starts up.

We can overcome this limitation by using anonymous inner bean configuration as follows.

<bean id="customDataItemReader" class="com.reader.customerDataItemReader" scope="prototype">       <property name="lineMapper">             <bean class="com.mapper.CustomLineMapper">                     <property name="lineTokenizer">                         <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">                                  <property name="delimiter" value="," />                         </bean>                     </property>                     <property name="fieldSetMapper">                         <bean class="com.mapper.SegmentFieldSetMapper" />                     </property>             </bean>        </property> </bean>

Write a CustomLineMapper by extending DefaultLineMapper and override 

mapLine(String line, int lineNumber) throws Exception method according to requirements.

Example: Now we need use pipe(|) symbol as delimiter if existed in the line, else need to use comma(,) as default delimiter.

public class CustomLineMapper<T> extends DefaultLineMapper<T> {     private LineTokenizer lineTokenizer;     private FieldSetMapper<CustomerInformationVO> fieldSetMapper;     public <T> mapLine(String line, int lineNumber) throws Exception {        try {            setLineTokenizer(new DelimitedLineTokenizer(StringUtils.contains(                   line, '|') ? '|' : ','));            return this.fieldSetMapper.mapFieldSet(this.lineTokenizer                   .tokenize(line));        } catch (Exception ex) {            throw new FlatFileParseException("Parsing error at line: "                   + lineNumber + ", input=[" + line + "]", ex, line,                   lineNumber);        }     }     public LineTokenizer getLineTokenizer() {        return lineTokenizer;     }     public void setLineTokenizer(LineTokenizer lineTokenizer) {        this.lineTokenizer = lineTokenizer;     }     public void afterPropertiesSet() {        Assert.notNull(this.lineTokenizer, "The LineTokenizer must be set");        Assert.notNull(this.fieldSetMapper, "The FieldSetMapper must be set");     }     public FieldSetMapper<CustomerInformationVO> getFieldSetMapper() {        return fieldSetMapper;     }     public void setFieldSetMapper(            FieldSetMapper<CustomerInformationVO> fieldSetMapper) {        this.fieldSetMapper = fieldSetMapper;     } }