Spring-batch @BeforeStep不适用于@StepScope

Question

我正在使用Spring Batch版本2.2.4.RELEASE我试着用有状态的ItemReader,ItemProcessor和ItemWriter bean编写一个简单的例子.

public class StatefulItemReader implements ItemReader<String> {

    private List<String> list;

    @BeforeStep
    public void initializeState(StepExecution stepExecution) {
        this.list = new ArrayList<>();
    }

    @AfterStep
    public ExitStatus exploitState(StepExecution stepExecution) {
        System.out.println("******************************");
        System.out.println(" READING RESULTS : " + list.size());

        return stepExecution.getExitStatus();
    }

    @Override
    public String read() throws Exception {
        this.list.add("some stateful reading information");
        if (list.size() < 10) {
            return "value " + list.size();
        }
        return null;
    }
}

在我的集成测试中,我在一个内部静态java配置类中声明我的bean,如下所示:

@ContextConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
public class SingletonScopedTest {

    @Configuration
    @EnableBatchProcessing
    static class TestConfig {
        @Autowired
        private JobBuilderFactory jobBuilder;
        @Autowired
        private StepBuilderFactory stepBuilder;

        @Bean
        JobLauncherTestUtils jobLauncherTestUtils() {
            return new JobLauncherTestUtils();
        }

        @Bean
        public DataSource dataSource() {
            EmbeddedDatabaseBuilder embeddedDatabaseBuilder = new EmbeddedDatabaseBuilder();
            return embeddedDatabaseBuilder.addScript("classpath:org/springframework/batch/core/schema-drop-hsqldb.sql")
                    .addScript("classpath:org/springframework/batch/core/schema-hsqldb.sql")
                    .setType(EmbeddedDatabaseType.HSQL)
                    .build();
        }

        @Bean
        public Job jobUnderTest() {
            return jobBuilder.get("job-under-test")
                    .start(stepUnderTest())
                    .build();
        }

        @Bean
        public Step stepUnderTest() {
            return stepBuilder.get("step-under-test")
                    .<String, String>chunk(1)
                    .reader(reader())
                    .processor(processor())
                    .writer(writer())
                    .build();
        }

        @Bean
        public ItemReader<String> reader() {
            return new StatefulItemReader();
        }

        @Bean
        public ItemProcessor<String, String> processor() {
            return new StatefulItemProcessor();
        }

        @Bean
        public ItemWriter<String> writer() {
            return new StatefulItemWriter();
        }
    }

    @Autowired
    JobLauncherTestUtils jobLauncherTestUtils;

    @Test
    public void testStepExecution() {
        JobExecution jobExecution = jobLauncherTestUtils.launchStep("step-under-test");

        assertEquals(ExitStatus.COMPLETED, jobExecution.getExitStatus());
    }
}

这个测试通过.

但是,只要我将StatefulItemReader定义为步骤范围的bean(对于有状态的读者更好),就不再执行"before step"代码.

...
    @Bean
    @StepScope
    public ItemReader<String> reader() {
        return new StatefulItemReader();
    }
...

我注意到处理器和我的编写器bean的相同问题.

我的代码出了什么问题？是否与此已解决的问题有关:https://jira.springsource.org/browse/BATCH-1230

我可以在GitHub上找到我的几个JUnit测试的整个Maven项目:https://github.com/galak75/spring-batch-step-scope

提前感谢您的回答.

Answer 1

配置bean时如下:

@Bean
@StepScope
public MyInterface myBean() {
    return new MyInterfaceImpl();
}

你告诉Spring使用代理模式ScopedProxyMode.TARGET_CLASS.但是,通过返回MyInterface代替MyInterfaceImpl,代理只能看到方法MyInterface.这可以防止Spring Batch能够找到MyInterfaceImpl已经使用监听器注释注释的方法@BeforeStep.配置它的正确方法是返回MyInterfaceImpl您的配置方法,如下所示:

@Bean
@StepScope
public MyInterfaceImpl myBean() {
    return new MyInterfaceImpl();
}

我们在启动时添加了一条警告日志消息指出,当我们查找带注释的侦听器方法时,如果对象被代理并且目标是一个接口,我们将无法在带有注释的实现类上找到方法他们.