Spring Batch ItemProcessor Example

Learn to use ItemProcessor to add business logic after reading the input and before passing it to writer for writing to the file/database. It should be noted that while it’s possible to return a different datatype than the one provided as input, it’s not necessary.

Returning null from ItemProcessor indicates that the item should not be continued to be processed.

How to write ItemProcessor

Below given ItemProcessor implementation does following tasks:

  • Validate if 'id' field is set.
  • Validate if 'id' field is parsable to integer.
  • Validate if 'id' field is positive integer greater than zero.
  • If validation fails then return null, which indicate that don’t process the record.
  • If validation succeeds then return the Employee object, as it is.
import org.springframework.batch.item.ItemProcessor;
import com.howtodoinjava.demo.model.Employee;

public class ValidationProcessor implements ItemProcessor<Employee,Employee> 
	public Employee process(Employee employee) throws Exception 
		if (employee.getId() == null){
			System.out.println("Missing employee id : " + employee.getId());
			return null;
			if(Integer.valueOf(employee.getId()) <= 0) {
				System.out.println("Invalid employee id : " + employee.getId());
				return null;
		catch (NumberFormatException e) {
			System.out.println("Invalid employee id : " + employee.getId());
			return null;
		return employee;

How to use ItemProcessor

You shall use SimpleStepBuilder.processor() to set processor instance during setting the tasklets in step.

package com.howtodoinjava.demo.config;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.launch.support.RunIdIncrementer;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.LineMapper;
import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
import org.springframework.batch.item.file.mapping.DefaultLineMapper;
import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;

import com.howtodoinjava.demo.model.Employee;

public class BatchConfig {
	private JobBuilderFactory jobBuilderFactory;

	private StepBuilderFactory stepBuilderFactory;

	private Resource inputResource;

	public Job readCSVFilesJob() {
		return jobBuilderFactory
				.incrementer(new RunIdIncrementer())

	public Step step1() {
		return stepBuilderFactory
				.<Employee, Employee>chunk(1)

	public ItemProcessor<Employee, Employee> processor() {
		return new ValidationProcessor();

	public FlatFileItemReader<Employee> reader() {
		FlatFileItemReader<Employee> itemReader = new FlatFileItemReader<Employee>();
		return itemReader;

	public LineMapper<Employee> lineMapper() {
		DefaultLineMapper<Employee> lineMapper = new DefaultLineMapper<Employee>();
		DelimitedLineTokenizer lineTokenizer = new DelimitedLineTokenizer();
		lineTokenizer.setNames(new String[] { "id", "firstName", "lastName" });
		lineTokenizer.setIncludedFields(new int[] { 0, 1, 2 });
		BeanWrapperFieldSetMapper<Employee> fieldSetMapper = new BeanWrapperFieldSetMapper<Employee>();
		return lineMapper;

	public ConsoleItemWriter<Employee> writer() {
		return new ConsoleItemWriter<Employee>();

ItemProcessor Demo

I am processing this CSV with above configuration.


Start the job and watch the console.

2018-07-11 14:59:00 INFO  - Job: [SimpleJob: [name=readCSVFilesJob]] launched with the following parameters: [{JobID=1531301340005}]

2018-07-11 14:59:00 INFO  - Executing step: [step1]
Employee [id=1, firstName=Lokesh, lastName=Gupta]
Employee [id=2, firstName=Amit, lastName=Mishra]
Employee [id=3, firstName=Pankaj, lastName=Kumar]

Invalid employee id : abc

Employee [id=4, firstName=David, lastName=Walsh]

2018-07-11 14:59:00 INFO  - Job: [SimpleJob: [name=readCSVFilesJob]] completed with the following parameters: [{JobID=1531301340005}] and the following status: [COMPLETED]

Drop me your questions in comments section.

Happy Learning !!

Ref: ItemProcessor Java Doc

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