在 spring 批次中重试 reader

Question

我写了一个 spring 批处理应用程序，但项目 reader 抛出异常。如何重试项目 reader？我已经添加了 @EnableRetry 申请 class，下面是 reader 代码

@Bean
  @Retryable(include = { RuntimeException.class }, maxAttempts = 1000, backoff = @Backoff(delay = 0))
  public ItemReader<Student> reader() {
    return new InMemoryStudentReader();
  }

下面是readerclass

public class InMemoryStudentReader implements ItemReader<Student> {

  @Autowired
  private JdbcTemplate jdbcTemplate;

  private int nextStudentIndex;
  private List<Student> studentData;

  public InMemoryStudentReader() {
    initialize();
  }


  private void initialize() {
    Student s1 = new Student(1, "ABC");
    Student s2 = new Student(2, "DEF");
    Student s3 = new Student(3, "GHI");

    studentData = Collections.unmodifiableList(Arrays.asList(s1, s2,s3));
    nextStudentIndex = 0;
  }

  @Override
  public Student read() throws Exception {
    Student nextStudent = null;

    if (nextStudentIndex < studentData.size()) {
      int a =jdbcTemplate.queryForObject("SELECT id FROM val LIMIT 1", Integer.class);
      if(a == 2) {
        throw new RuntimeException("Exception");
      }
      nextStudent = studentData.get(nextStudentIndex);
      nextStudentIndex++;
    } else {
      nextStudentIndex = 0;
    }

    return nextStudent;
  }
}

但即使在这之后 reader 也没有重试，作业失败了

Answer 1

您要在 bean 定义方法上添加 @Retryable。此方法仅在配置时由 Spring 调用以创建您的 bean 的实例并且不太可能失败。

您应该在 reader 的 read 方法上添加注释，当步骤为运行时在运行时调用该方法并可能引发异常：

@Override
@Retryable(include = { RuntimeException.class }, maxAttempts = 1000, backoff = @Backoff(delay = 0))
public Student read() throws Exception {
   ...
}

在 spring 批次中重试 reader

Retrying reader in spring Batch

java

spring

batch-processing

spring-batch