spring-batch : load and use a property file - spring

Question

I am new on Spring batch so am here to ask some basic advice.
What is the best approach to load a config file in memory (or bean) and use its content while the spring Job/step are running ?
I am not sure but based on some google search I found the below scenario even if I dont quite understand why I should define a writer even if i dont need it :
step1 : load config file (the content is two field delimited by =)
step2 : perform some java code and use the previous config file
so for the step 1 :
<bean id="inputFile" class="org.springframework.core.io.FileSystemResource" scope="step">
<constructor-arg value="path_config_file"/>
</bean>
<bean id="readerConfigFile" class="org.springframework.batch.item.file.FlatFileItemReader" scope="step">
<property name="resource" ref="inputFile"/>
<property name="lineMapper">
<bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
<property name="lineTokenizer">
<bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
<property name="names" value="field,value"/>
<property name="delimiter" value="="/>
</bean>
</property>
<property name="fieldSetMapper">
<bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
<property name="prototypeBeanName" value="configProperties"/>
</bean>
</property>
</bean>
</property>
</bean>
<bean id="outputConfig" class="outputConfig"></bean>
<bean id="configProperties" class="configProperties" scope="prototype"/>
so my question are :
How can I use the information gathered in the file ? Should I put them in the Java bean ?
How can I pas this info between different step or make them persistent in the whole application life-cycle ?
Would you recommend to use a itemProcessor to achieve the above ?
Any advice are most than welcome

Answer 1

I'm a bit confused about your questions because I think you only need to load a properties file in spring context using a PropertiesFactoryBean:
<bean id="config" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
<property name="location">
<value>file:path_config_file</value>
</property>
</bean>
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="propertiesArray">
<list>
<ref bean="config"/>
</list>
</property>
</bean>
and you can refer to property values using ${} placeholder; but this solution is unrelated to spring-batch; I don't need it!
About your questions:
Using a POJO is a good way because spring-batch offers in-box mapping strategies (BeanWrapperFieldSetMapper in your case)
Objects used in a job are accessible only in job context, not in application context (this is why I think you need a PropertiesFactoryBean).To pass object between steps read How can we share data between the different steps of a Job in Spring Batch?
ItemProcessor is requested if you need to convert an object T read from a ItemReader<T> to an object of type S written by an ItemWriter<S>. So no, you don't need an ItemProcessor.
I hope I was clear, English is not my native language