• https://chatgpt.com/c/6752bc19-2988-800d-a0b6-b2d118c74141

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Spring batch

• Architecture
• configure a jobRepository
• Job parameter
• Building job with multiple Steps

Job flow

• status control
• job flow
• conditional Flow
• parallel flow
• Listeners
• StepExecutionListener
• Restarting jobs
• Reusability - reuse same step among several job.
• nested jobs

job1
    .listener(listener)                                     # event - job start,end
    .next(step2())
    .next(job2Reference())                                          # nested
    .split(new SimpleAsyncTaskExecutor()).add(step3(), step4())     # parallel

Step1.
    .<InputType, OutputType>chunk(10)
    .listener(listener)                                     # event - step start,end

Reading

• chuck-oriented processing
• ItemReader
• configure chuck-oriented steps
• reading from DB (single thread)
• reading from DB (multiple thread)

   return new JdbcCursorItemReader<>()
  

Writing

• ItemWriter
• Writing flat files
• Writing to a database with PreparedStatements
• Writing to a database with named parameters
• Writing a JSON file

 return new JdbcBatchItemWriter<>();
 FlatFileItemWriter<OutputType> writer = new FlatFileItemWriter<>();

processing Items

• ItemProcessor
• ItemProcessor Bean Validation
• Implementing custom processor logic
• Chaining ItemProcessors
• Filtering batch data

Resilient jobs

• skip logic for jobs
• retry logic for steps
• multithreaded steps

Step1.
    .skip(Exception.class)
    .skipLimit(10)

Step1.
    .retry(Exception.class)
    .retryLimit(3) 

Step1.    
    .taskExecutor(new SimpleAsyncTaskExecutor())