Spring Batch简单入门（二）- Job配置

朴灿烈づ我的快乐病毒、 2022-05-13 05:20 275阅读 0赞

[上一章][Link 1]，我们简单介绍了Spring Batch相关知识，今天我们进一步学习有关如何配置一个简单的Job。我们重新看下这张图。  
![这里写图片描述][70]

一个**Job**对应**N**个**Step**（N>=1）,一个**Step**包含一个**Reader**，一个**Processor**，一个**Writer**。我们的代码组织如下：  
![这里写图片描述][70 1]

*  定义**ItemReader**

@Bean
        @Qualifier("repositoryItemReader")
        public RepositoryItemReader<User> repositoryItemReader() {
            Map<String, Sort.Direction> map = new HashMap<>();
            map.put("id", Sort.Direction.DESC);
            RepositoryItemReader<User> repositoryItemReader = new RepositoryItemReader<>();
            repositoryItemReader.setRepository(userReaderRepository);
            repositoryItemReader.setPageSize(5);
            repositoryItemReader.setMethodName("findAll");
            repositoryItemReader.setSort(map);
            return repositoryItemReader;
        }

*  定义**ItemProcessor**

@Override
        public People process(User user) throws Exception {
            final String firstName = user.getFirstName().toUpperCase();
            final String lastName = user.getLastName().toUpperCase();
            final People transformedPeople = People.builder()
                    .firstName(firstName)
                    .lastName(lastName)
                    .personId(UUID.randomUUID().toString())
                    .build();
            log.info("converting (" + user + ") into (" + transformedPeople + ")");
            return transformedPeople;
        }

*  定义**ItemWriter**

@Bean
        @Qualifier("repositoryItemWriter")
        public RepositoryItemWriter<People> repositoryItemWriter() {
            RepositoryItemWriter<People> peopleRepositoryItemWriter = new RepositoryItemWriter<>();
            peopleRepositoryItemWriter.setRepository(peopleCrudRepository);
            peopleRepositoryItemWriter.setMethodName("save");
            return peopleRepositoryItemWriter;
        }

*  定义**Step**如下：

@Bean
        public Step stepWithRepository() {
            return stepBuilderFactory.get("stepWithRepository")
                    .<User, People>chunk(10)
                    .reader(repositoryItemReader)
                    .processor(userPeopleItemProcessor)
                    .writer(repositoryItemWriter)
                    .build();
        }

*  定义**Job**

@Configuration
    public class RepositoryJob { 
        @Autowired
        private JobBuilderFactory jobBuilderFactory;
    
        @Autowired
        private Step stepWithRepositoryReaderAndWriter;
    
        @Autowired
        private Step stepWithRepository;
    
        @Bean
        public Job jobWithRepositoryStep(@Autowired CommonJobListener commonJobListener) {
            return jobBuilderFactory.get("jobWithRepositoryStep")
                    .incrementer(new RunIdIncrementer())
                    .listener(commonJobListener)
                    .flow(stepWithRepository)
                    .end()
                    .build();
        }
    }

*  暴露**Rest**接口，以**JobLauncher**启动指定**Job**

@Autowired
        private JobLaunchService jobLaunchService;
    
        @Autowired
        private Job jobWithRepositoryStep;
    
        @GetMapping
        public JobResult launchJobWithRepositoryStep() {
            return jobLaunchService.launchJob(jobWithRepositoryStep);
        }

*  其中**JobLaunchService**定义如下：

@Service
    @Slf4j
    public class JobLaunchService { 
        @Autowired
        private JobLauncher jobLauncher;
    
        public JobResult launchJob(Job job) {
            try {
                JobParameters jobParameters = new JobParametersBuilder()
                        .addDate("timestamp", Calendar.getInstance().getTime())
                        .toJobParameters();
                JobExecution jobExecution = jobLauncher.run(job, jobParameters);
                return JobResult.builder()
                        .jobName(job.getName())
                        .jobId(jobExecution.getJobId())
                        .jobExitStatus(jobExecution.getExitStatus())
                        .timestamp(Calendar.getInstance().getTimeInMillis())
                        .build();
            } catch (Exception e) {
                log.error(e.getMessage());
                throw new RuntimeException("launch job exception ", e);
            }
        }
    }

这样，一个完整的**Job**就配置完成了，你可以通过简单的HTTP接口调用启动指定**Job**。更多源码请参考：**[https://github.com/ypmc/spring-cloud/tree/master/spring-batch][https_github.com_ypmc_spring-cloud_tree_master_spring-batch]**

[Link 1]: https://blog.csdn.net/kangkanglou/article/details/82595136
[70]: /images/20220513/949f28000e4b4922b405fab3d85d2ec3.png
[70 1]: /images/20220513/0976f513214847669be5fd614aeabd07.png
[https_github.com_ypmc_spring-cloud_tree_master_spring-batch]: https://github.com/ypmc/spring-cloud/tree/master/spring-batch