Spring batch Decider

In this example, we’ll see how to make the use of Spring batch decider with the various transitions.

MainApp.java

@SpringBootApplication
@EnableBatchProcessing
@RequiredArgsConstructor
public class DeciderApplication {

   private final JobBuilderFactory jobBuilderFactory;
   private final StepBuilderFactory stepBuilderFactory;

   @Bean
   public DeliveryDecider decider(){
      return new DeliveryDecider();
   }

   @Bean
   public Step leaveAtDoorStep() {
      return this.stepBuilderFactory.get("leaveAtDoorStep").tasklet((contribution, chunkContext) -> {
         System.out.println(">>>> Leaving the package at the door.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step storePackageStep() {
      return this.stepBuilderFactory.get("storePackageStep").tasklet((contribution, chunkContext) -> {
         System.out.println(">>>> Storing the package while the customer address is located.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step givePackageToCustomerStep() {
      return this.stepBuilderFactory.get("givePackageToCustomer").tasklet((contribution, chunkContext) -> {
         System.out.println(">>>> Given the package to the customer.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step driveToAddressStep() {
      boolean GOT_LOST = false;
      return this.stepBuilderFactory.get("driveToAddressStep").tasklet((contribution, chunkContext) -> {

         if(GOT_LOST) {
            throw new RuntimeException(">>>> Got lost driving to the address");
         }

         System.out.println(">>>> Successfully arrived at the address.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step packageItemStep() {
      return this.stepBuilderFactory.get("packageItemStep").tasklet((contribution, chunkContext) -> {
         String item = chunkContext.getStepContext().getJobParameters().get("item").toString();
         String date = chunkContext.getStepContext().getJobParameters().get("run.date").toString();

         System.out.println(String.format(">>>> The %s has been packaged on %s.", item, date));
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Job deliverPackageJob() {
      return this.jobBuilderFactory.get("deliverPackageJob")
            .incrementer(new RunIdIncrementer())
            .start(packageItemStep())
            .next(driveToAddressStep())
               .on("FAILED").to(storePackageStep())
            .from(driveToAddressStep())
               .on("*").to(decider()).on("PRESENT").to(givePackageToCustomerStep())
            .from(decider())
               .on("NOT_PRESENT").to(leaveAtDoorStep())
            .end()
            .build();
   }

   public static void main(String[] args) {
      SpringApplication.run(DeciderApplication.class, args);
   }
}

DeliveryDecider.java

public class DeliveryDecider implements JobExecutionDecider {
    @Override
    public FlowExecutionStatus decide(JobExecution jobExecution, StepExecution stepExecution) {
        // Based on timezone you're in, you need to tweak conditions to get different results
        String result = LocalDateTime.now().getHour() > 12 ? "PRESENT" : "NOT_PRESENT";
        System.out.println("Decider result is:  " + result);
        return new FlowExecutionStatus(result);
    }
}

application.properties

spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.platform=mysql

spring.batch.initialize-schema=always

console output —

If Decider, changing the condition

String result = LocalDateTime.now().getHour() < 12 ? "PRESENT" : "NOT_PRESENT";

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ReceiptDecider.java

public class ReceiptDecider implements JobExecutionDecider {

   @Override
   public FlowExecutionStatus decide(JobExecution jobExecution, StepExecution stepExecution) {
      
      String exitCode = new Random().nextFloat() < .70f ? "CORRECT":"INCORRECT";
      System.out.println("The item delivered is: " + exitCode);
      return new FlowExecutionStatus(exitCode);
   }
}

DeliveryDecider.java

public class DeliveryDecider implements JobExecutionDecider {
    @Override
    public FlowExecutionStatus decide(JobExecution jobExecution, StepExecution stepExecution) {
        // Based on timezone you're in, you need to tweak conditions to get different results
        String result = LocalDateTime.now().getHour() < 12 ? "PRESENT" : "NOT_PRESENT";
        System.out.println("Decider result is:  " + result);
        return new FlowExecutionStatus(result);
    }
}

DeciderApp.java

@SpringBootApplication
@EnableBatchProcessing
@RequiredArgsConstructor
public class DeciderApplication {

   private final JobBuilderFactory jobBuilderFactory;
   private final StepBuilderFactory stepBuilderFactory;

   @Bean
   public DeliveryDecider decider(){
      return new DeliveryDecider();
   }
   @Bean
   public JobExecutionDecider receiptDecider() {
      return new ReceiptDecider();
   }

   @Bean
   public Step thankCustomerStep() {
      return this.stepBuilderFactory.get("thankCustomerStep").tasklet((contribution, chunkContext) -> {
         System.out.println("Thanking the customer.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step refundStep() {
      return this.stepBuilderFactory.get("refundStep").tasklet((contribution, chunkContext) -> {
         System.out.println("Refunding customer money.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step leaveAtDoorStep() {
      return this.stepBuilderFactory.get("leaveAtDoorStep").tasklet((contribution, chunkContext) -> {
         System.out.println(">>>> Leaving the package at the door.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step storePackageStep() {
      return this.stepBuilderFactory.get("storePackageStep").tasklet((contribution, chunkContext) -> {
         System.out.println(">>>> Storing the package while the customer address is located.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step givePackageToCustomerStep() {
      return this.stepBuilderFactory.get("givePackageToCustomer").tasklet((contribution, chunkContext) -> {
         System.out.println(">>>> Given the package to the customer.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step driveToAddressStep() {
      boolean GOT_LOST = false;
      return this.stepBuilderFactory.get("driveToAddressStep").tasklet((contribution, chunkContext) -> {

         if(GOT_LOST) {
            throw new RuntimeException(">>>> Got lost driving to the address");
         }

         System.out.println(">>>> Successfully arrived at the address.");
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Step packageItemStep() {
      return this.stepBuilderFactory.get("packageItemStep").tasklet((contribution, chunkContext) -> {
         String item = chunkContext.getStepContext().getJobParameters().get("item").toString();
         String date = chunkContext.getStepContext().getJobParameters().get("run.date").toString();

         System.out.println(String.format(">>>> The %s has been packaged on %s.", item, date));
         return RepeatStatus.FINISHED;
      }).build();
   }

   @Bean
   public Job deliverPackageJob() {
      return this.jobBuilderFactory.get("deliverPackageJob")
            .start(packageItemStep())
            .next(driveToAddressStep())
            .on("FAILED").to(storePackageStep())
            .from(driveToAddressStep())
            .on("*").to(decider())
            .on("PRESENT").to(givePackageToCustomerStep())
            .next(receiptDecider()).on("CORRECT").to(thankCustomerStep())
            .from(receiptDecider()).on("INCORRECT").to(refundStep())
            .from(decider())
            .on("NOT_PRESENT").to(leaveAtDoorStep())
            .end()
            .build();
   }

   public static void main(String[] args) {
      SpringApplication.run(DeciderApplication.class, args);
   }
}

application.properties

spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.platform=mysql

spring.batch.initialize-schema=always

Tweak the conditions in DeliveryDecider —