java - Spring 批处理 : How to catch exception message with skip method in spring batch?

Question

我是Spring Batch的新手。我的问题是如何使用 spring-batch 中的skip方法捕获异常？据我所知，当Spring Batch中发生一些异常时，我们可以使用skip方法来跳过它们。但是如何使用skip方法获取异常消息呢？有人建议我使用 SkipListener ，这个类有 onSkipInProcess() 等三个回调方法，但对我来说没有用。并且 ItemProcessListener 也不起作用。

代码如下:(我使用skip方法来忽略异常，并使用两个监听器来接收异常信息)

Step mainStep = stepBuilder.get("run")
        .<ItemProcessing, ItemProcessing>chunk(5)
        .faultTolerant()
        .skip(IOException.class).skip(SocketTimeoutException.class)//skip IOException here
        .skipLimit(2000)
        .reader(reader)
        .processor(processor)
        .writer(writer)
        .listener(stepExecListener)
        .listener(new ItemProcessorListener()) //add process listener
        .listener(new SkipExceptionListener()) //add skip exception listner
        .build();

ItemProcessorListener 如下所示:

//(this class implements ItemProcessListener )
{
    @Override
    public void beforeProcess(Object item) {
        // TODO Auto-generated method stub

    }
    @Override
    public void afterProcess(Object item, Object result) {
        logger.info("invoke remote finished, item={},result={}",item,result);

    }
    @Override
    public void onProcessError(Object item, Exception e) {
        logger.error("invoke remote error, item={},exception={},{}",item,e.getMessage(),e);
    }
}

SkipExceptionListener 如下所示:

//(implements SkipListener<Object, Object>)
{

    @Override
    public void onSkipInRead(Throwable t) {
        // TODO Auto-generated method stub      
    }

    @Override
    public void onSkipInWrite(Object item, Throwable t) {
        // TODO Auto-generated method stub      
    }

    @Override
    public void onSkipInProcess(Object item, Throwable t) {
        logger.info("invoke remote finished,item={},itemJsonStr={},errMsg={},e={}",
                    item,
                    JSONObject.toJSONString(item),
                    t.getMessage(),
                    t);
    }
}

问题是所有记录器都不起作用。实际上skip方法确实工作得很好，我可以在表batch_step_execution中获取skip计数。我不确定这两个监听器是否被回调。谁能告诉我我该怎么办？或者还有其他什么吗？非常感谢。

Answer 1

How to catch exception message with skip method in spring batch?

您可以通过实现 SkipListener 接口(interface)或扩展 SkipListenerSupport 类来实现这一点。 SkipListener 接口(interface)中的所有方法都有一个 Throwable 参数，该参数是引发的异常并导致项目被跳过。您可以在此处获取异常消息。这是一个例子:

import java.util.Arrays;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.SkipListener;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.support.ListItemReader;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableBatchProcessing
public class MyJob {

    @Autowired
    private JobBuilderFactory jobs;

    @Autowired
    private StepBuilderFactory steps;

    @Bean
    public ItemReader<Integer> itemReader() {
        return new ListItemReader<>(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
    }

    @Bean
    public ItemWriter<Integer> itemWriter() {
        return items -> {
            for (Integer item : items) {
                System.out.println("item = " + item);
            }
        };
    }

    @Bean
    public ItemProcessor<Integer, Integer> itemProcessor() {
        return item -> {
            if (item.equals(7)) {
                throw new IllegalArgumentException("Sevens are not accepted!!");
            }
            return item;
        };
    }

    @Bean
    public Step step() {
        return steps.get("step")
                .<Integer, Integer>chunk(5)
                .reader(itemReader())
                .processor(itemProcessor())
                .writer(itemWriter())
                .faultTolerant()
                .skip(IllegalArgumentException.class)
                .skipLimit(3)
                .listener(new MySkipListener())
                .build();
    }

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

    public static class MySkipListener implements SkipListener<Integer, Integer> {

        @Override
        public void onSkipInRead(Throwable t) {

        }

        @Override
        public void onSkipInWrite(Integer item, Throwable t) {

        }

        @Override
        public void onSkipInProcess(Integer item, Throwable t) {
            System.out.println("Item " + item + " was skipped due to: " + t.getMessage());
        }
    }

    public static void main(String[] args) throws Exception {
        ApplicationContext context = new AnnotationConfigApplicationContext(MyJob.class);
        JobLauncher jobLauncher = context.getBean(JobLauncher.class);
        Job job = context.getBean(Job.class);
        jobLauncher.run(job, new JobParameters());
    }

}

在此示例中，MySkipListener 实现 SkipListener 并按照您尝试执行的操作从异常中获取消息。该示例读取从 1 到 10 的数字并跳过数字 7。您可以运行 main 方法并应看到以下输出:

item = 1
item = 2
item = 3
item = 4
item = 5
item = 6
item = 8
item = 9
item = 10
Item 7 was skipped due to: Sevens are not accepted!!

我希望这会有所帮助。