SpringBoot_BatchProcessing

SpringBoot_BatchProcessing /** *

• reader() -> creates ItemReader which looks for sample-data.csv file and parse each item to transform information into User object

• processer() -> creates instance of our UserProcessor

• writer() -> create itemWriter which is aimed to JDBC Destination and gets dataSource created by @EnableBatchProcessing it also includes SQL statement needed to insert User to db.

• csvToDbJob() -> defines Job. Jobs are built from Steps each job involve reader, processor and writer.

•    In this Job Defination we need incrementer because jobs use a database to maintain execution state.You then list each 			step, of which 	this job has only one step.
  

• The job ends, and the Java API produces a perfectly configured job.

• csvToDbStep() -> In the step definition, you define how much data to write at a time.

• In this case, it writes up to ten records at a time.

• Next, you configure the reader, processor, and writer using the injected bits from earlier.

• chunk() is prefixed <User,User> because it’s a generic method.

• This represents the input and output types of each "chunk" of processing, and lines up with ItemReader and ItemWriter.

  • JobCompletionNotificationListener -> listens for when a job is BatchStatus.COMPLETED, and then uses JdbcTemplate to inspect the results.
  • @Configuration tags the class as a source of bean definitions for the application context
  • @EnableAutoConfiguration tells Spring Boot to start adding beans based on classpath settings, other beans, and various property settings.
  • Normally you would add @EnableWebMvc for a Spring MVC app, but Spring Boot adds it automatically when it sees spring-webmvc on the classpath.
  • This flags the application as a web application and activates key behaviors such as setting up a DispatcherServlet
  • @ComponentScan tells Spring to look for other components, configurations, and services in the which package, allowing it to find the controllers. */