如果应用程序实现 CommandLineRunner，则 Spring Batch 重试在 Java 中不起作用

Question

作为参考Retry not working with Spring Batch with Java Config 我签入了以下春季批处理阅读器重试示例https://github.com/atulkulkarni18/spring-batch-reader-retry 的代码，并且重试功能按预期工作。 但是实现 CommandLineRunner（如下面的代码所示），重试功能不起作用......有人可以建议吗？

@SpringBootApplication
@EnableBatchProcessing
@Data
@NoArgsConstructor
@AllArgsConstructor
@EnableRetry
public class Stack56170179Application implements CommandLineRunner {

    @Autowired
    JobLauncher jobLauncher;

    @Autowired
    private JobBuilderFactory jobs;

    @Autowired
    private StepBuilderFactory steps;

    public static void main(String[] args) {
        SpringApplication.run(Stack56170179Application.class, args);
    }

    @Bean
    public Job job() {
        return jobs.get("myJob").start(step1()).build();
    }

    @Bean
    public Step step1() {
        return steps.get("step1").<String, String>chunk(1).reader(myReader())
                .processor(myProcessor())
                .writer(myWriter())
                .build();
    }

    @Override
    public void run(String... args) throws Exception {
        JobParameters params = new JobParametersBuilder()
                .addString("JobID", String.valueOf(System.currentTimeMillis()))
                .toJobParameters();
        jobLauncher.run(job(), params);
    }

    @Bean
    @StepScope
    public MyReader myReader() {
        return new MyReader();
    }

    @Bean
    @StepScope
    public MyProcessor myProcessor() {
        return new MyProcessor();
    }

    @Bean
    @StepScope
    public MyWriter myWriter() {
        return new MyWriter();
    }

}

public class MyReader implements ItemReader<String> {

    private long count;
    private long retryCount;

    @Override
    @Retryable(include = { MyException.class }, maxAttempts = 5)
    public String read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
        final long value = count;
        System.out.println("MyReader : " + value);

        if (value == 3 && retryCount <= 2) {
            retryCount++;
            System.out.println("****");
            Thread.sleep(500);
            throw new MyException();
        }

        if (value < 5) {
            count++;
            Thread.sleep(500);
            return String.valueOf(value);
        } else {
            return null;
        }
    }
}


public class MyProcessor implements ItemProcessor<String, String> {

    @Override
    public String process(final String arg0) throws Exception {
        System.out.println("MyProcessor : " + arg0);
        return arg0;
    }

}


public class MyWriter implements ItemWriter<String> {

    @Override
    public void write(final List<? extends String> arg0) throws Exception {
        System.out.println("MyWriter : " + arg0);
    }

}

public class MyException extends Exception {

    private static final long serialVersionUID = 1L;

}

预期输出：

MyReader : 0
MyProcessor : 0
MyWriter : [0]
MyReader : 1
MyProcessor : 1
MyWriter : [1]
MyReader : 2
MyProcessor : 2
MyWriter : [2]
MyReader : 3
****
MyReader : 3
****
MyReader : 3
****
MyReader : 3
MyProcessor : 3
MyWriter : [3]
MyReader : 4
MyProcessor : 4
MyWriter : [4]
MyReader : 5

Answer 1

问题不在于CommandLineRunner，而在于MyReader 对象。您已经创建了普通对象并且它不是 Spring 管理的。 尝试创建像

这样的 spring 托管 bean

 @Bean
 @StepScope
 public MyReader myReader() {
    return new MyReader();
 }

并在方法step1() 中使用myReader() 而不是new MyReader()。

希望对您有所帮助！