#11 spring batch: @JobScope, @StepScope

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

@@ -14,7 +14,7 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
-@Configuration
+//@Configuration
 @RequiredArgsConstructor
 public class ScopeConfiguration {
 

spring-batch/basic/src/main/java/io/springbatch/basic/flow/ScopeConfiguration2.java

@@ -0,0 +1,95 @@
+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 ScopeConfiguration2 {
+
+    private final JobBuilderFactory jobBuilderFactory;
+    private final StepBuilderFactory stepBuilderFactory;
+
+    /*
+        1. Proxy 객체 생성
+            - @JobScope, @StepScope 어노테이션이 붙은 빈 선언은 내부적으로 빈의 Proxy 객체가 생성
+                - @JobScope
+                    - @Scope(value="job", proxyMode=ScopedProxyMode.TARGET_CLASS)
+                - @StepScope
+                    - @Scope(value="step", proxyMode=ScopedProxyMode.TARGET_CLASS)
+
+            - Job 실행 시 Proxy 객체가 실제 빈을 호출해서 해당 메소드를 실행 시키는 구조
+
+        2. JobScope, StepScope
+            - Proxy 객체의 실제 대상이 되는 Bean 을 등록, 해제하는 역할
+            - 실제 빈을 저장하고 있는 JobContext, StepContext 를 가지고 있다.
+
+        3. JobContext, StepContext
+            - 스프링 컨테이너에서 생성된 빈을 저장하는 컨텍스트 역할
+            - Job 의 실행 시점에서 프록시 객체가 실제 빈을 참조할 때 사용
+     */
+    @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;
+        });
+    }
+
+}