#11 spring batch: @JobScope, @StepScope

spring-batch/basic/src/main/java/io/springbatch/basic/flow/CustomJobListener.java

@@ -0,0 +1,17 @@
+package io.springbatch.basic.flow;
+
+import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobExecutionListener;
+
+public class CustomJobListener implements JobExecutionListener {
+
+    @Override
+    public void beforeJob(JobExecution jobExecution) {
+        jobExecution.getExecutionContext().putString("name", "user1");
+    }
+
+    @Override
+    public void afterJob(JobExecution jobExecution) {
+
+    }
+}

spring-batch/basic/src/main/java/io/springbatch/basic/flow/CustomStepListener.java

@@ -0,0 +1,18 @@
+package io.springbatch.basic.flow;
+
+import org.springframework.batch.core.ExitStatus;
+import org.springframework.batch.core.StepExecution;
+import org.springframework.batch.core.StepExecutionListener;
+
+public class CustomStepListener implements StepExecutionListener {
+
+    @Override
+    public void beforeStep(StepExecution stepExecution) {
+        stepExecution.getExecutionContext().putString("name2", "user2");
+    }
+
+    @Override
+    public ExitStatus afterStep(StepExecution stepExecution) {
+        return null;
+    }
+}

spring-batch/basic/src/main/java/io/springbatch/basic/flow/FlowStepConfiguration.java

@@ -12,7 +12,7 @@ import org.springframework.batch.repeat.RepeatStatus;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
-@Configuration
+//@Configuration
 @RequiredArgsConstructor
 public class FlowStepConfiguration {
 

spring-batch/basic/src/main/java/io/springbatch/basic/flow/ScopeConfiguration.java

@@ -0,0 +1,102 @@
+package io.springbatch.basic.flow;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.Step;
+import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
+import org.springframework.batch.core.configuration.annotation.JobScope;
+import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
+import org.springframework.batch.core.configuration.annotation.StepScope;
+import org.springframework.batch.core.launch.support.RunIdIncrementer;
+import org.springframework.batch.core.step.tasklet.Tasklet;
+import org.springframework.batch.repeat.RepeatStatus;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@RequiredArgsConstructor
+public class ScopeConfiguration {
+
+    private final JobBuilderFactory jobBuilderFactory;
+    private final StepBuilderFactory stepBuilderFactory;
+
+    /*
+        1. Scope
+            - 스프링 컨테이너 에서 빈이 관리되는 범위
+            - singleton, prototype, request, session, application 있으며 기본은 singleton
+
+        2. 스프링 배치 스코프
+            @JobScope, @StepScope
+            - Job 과 Step 의 빈 생성과 실행에 관여하는 스코프
+            - 프록시 모드를 기본값으로 하는 스코프 - @Scope(value = "job", proxyMode = ScopedProxyMode.TARGET_CLASS)
+            - 해당 스코프가 선언되면 빈의 생성이 어플리케이션 구동시점이 아닌 빈의 실행시점에 이루어진다.
+                - @Values 를 주입해서 빈의 실행 시점에 값을 참조할 수 있으며 일종의 Lazy Binding 이 가능해진다.
+                - @Value("#{jobParameters[파라미터명]}"),
+                  @Value("#{jobExecutionContext[파라미터명]}"),
+                  @Value("#{stepExecutionContext[파라미터명]}")
+            - 프록시 모드로 빈이 선언되기 때문에 어플리케이션 구동시점에는 빈의 프록시 객체가 생성되어 실행 시점에 실제 빈을 호출.
+            - 병렬처리 시 각 스레드마다 생성된 스코프 빈이 할당되기 때문에 스레드에 안전하게 실행 가능
+
+        3. @JopScope
+            - Step 선언문에 정의
+            - @Value: jobParameter, jobExecutionContext 만 사용가능
+
+        4. @StepScope
+            - Tasklet 이나 ItemReader, ItemWriter, ItemProcessor 선언문에 정의
+            - @Value: jobParameter, jobExecutionContext, stepExecutionContext 사용가능
+     */
+    @Bean
+    public Job batchJob() {
+        return jobBuilderFactory.get("batchJob")
+                .incrementer(new RunIdIncrementer())
+                .start(step1(null))
+                .next(step2())
+                .listener(new CustomJobListener())
+                .build();
+    }
+
+    @Bean
+    @JobScope
+    public Step step1(@Value("#{jobParameters['message']}") String message) {
+
+        System.out.println("message = " + message);
+
+        return stepBuilderFactory.get("step1")
+                .tasklet(tasklet1(null))
+                .build();
+    }
+
+    @Bean
+    public Step step2() {
+        return stepBuilderFactory.get("step2")
+                .tasklet(tasklet2(null))
+                .listener(new CustomStepListener())
+                .build();
+    }
+
+    @Bean
+    @StepScope
+    public Tasklet tasklet1(@Value("#{jobExecutionContext['name']}") String name) {
+
+        System.out.println("name = " + name);
+
+        return ((stepContribution, chunkContext) -> {
+            System.out.println("tasklet1 was executed");
+            return RepeatStatus.FINISHED;
+        });
+    }
+
+    @Bean
+    @StepScope
+    public Tasklet tasklet2(@Value("#{stepExecutionContext['name2']}") String name2) {
+
+        System.out.println("name2 = " + name2);
+
+        return ((stepContribution, chunkContext) -> {
+            System.out.println("tasklet2 was executed");
+            return RepeatStatus.FINISHED;
+        });
+    }
+
+}

spring-batch/basic/src/main/resources/application.yml

@@ -24,11 +24,10 @@ spring:
       on-profile: mysql
 
   datasource:
-    hikari:
-      jdbc-url: jdbc:mysql://localhost:3306/springbatch?useUnicode=true&characterEncoding=utf8
-      username: root
-      password: 1234
-      driver-class-name: com.mysql.cj.jdbc.Driver
+    url: jdbc:mysql://localhost:3306/springbatch?useUnicode=true&characterEncoding=utf8
+    username: root
+    password: 1234
+    driver-class-name: com.mysql.cj.jdbc.Driver
 
   batch:
     jdbc: