Spring batch 如何访问itermWriterListener Spring批处理中的stepExecution内容

我想访问org.springframework.batch.core.ItemWriteListener中的StepExecution，但无法访问，我已尝试定义局部变量：

private-StepExecution-StepExecution；

并添加以下代码：

@BeforeStep
预处理前的公共无效（步骤执行步骤执行）{
this.StepExecution=StepExecution；
}

似乎beforstep代码从未执行过。是否仍有访问上下文的权限

---

关于

如果您想使用基于注释的方法，您不需要实现侦听器接口，Spring Batch将基于注释方法为每个对应的侦听器接口创建一个代理。下面是一个简单的例子：

import java.util.Arrays;
import java.util.List;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.annotation.AfterWrite;
import org.springframework.batch.core.annotation.BeforeStep;
import org.springframework.batch.core.annotation.BeforeWrite;
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.support.ListItemReader;
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 MyJobConfiguration {

    @Bean
    public Job job(JobBuilderFactory jobs, StepBuilderFactory steps) {
        return jobs.get("myJob")
                .start(steps.get("myStep")
                        .<Integer, Integer>chunk(5)
                        .reader(new ListItemReader<>(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)))
                        .writer(items -> items.forEach(System.out::println))
                        .listener(new MyListener())
                        .build())
                .build();
    }
    
    static class MyListener {

        private StepExecution stepExecution;

        @BeforeStep
        public void beforeStep(StepExecution stepExecution) {
            this.stepExecution = stepExecution;
        }
        
        @BeforeWrite
        public void beforeWrite(List<? extends Integer> items) {
            System.out.println("About to write items " + items + " in step " + stepExecution.getStepName());
        }

        @AfterWrite
        public void afterWrite(List<? extends Integer> items) {
            System.out.println("Successfully wrote items " + items + " in step " + stepExecution.getStepName());
        }

    }

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

}

在本例中，Spring Batch将创建一个polymorph代理（它同时实现

ItemWriteListener

和

StepExecutionListener

），您只能在该步骤中注册一次

About to write items [1, 2, 3, 4, 5] in step myStep
1
2
3
4
5
Successfully wrote items [1, 2, 3, 4, 5] in step myStep
About to write items [6, 7, 8, 9, 10] in step myStep
6
7
8
9
10
Successfully wrote items [6, 7, 8, 9, 10] in step myStep