一、SpringBatch 介紹

Spring Batch 是一個(gè)輕量級、全面的批處理框架，旨在支持開發(fā)對企業(yè)系統(tǒng)的日常操作至關(guān)重要的健壯的批處理應(yīng)用程序。Spring Batch 建立在人們期望的 Spring Framework 特性（生產(chǎn)力、基于 POJO 的開發(fā)方法和一般易用性）的基礎(chǔ)上，同時(shí)使開發(fā)人員可以在必要時(shí)輕松訪問和使用更高級的企業(yè)服務(wù)。

Spring Batch 不是一個(gè)調(diào)度框架。在商業(yè)和開源領(lǐng)域都有許多優(yōu)秀的企業(yè)調(diào)度程序（例如 Quartz、Tivoli、Control-M 等）。Spring Batch 旨在與調(diào)度程序結(jié)合使用，而不是替代調(diào)度程序。

二、業(yè)務(wù)場景

我們在業(yè)務(wù)開發(fā)中經(jīng)常遇到這種情況：

Spring Batch 支持以下業(yè)務(wù)場景：

定期提交批處理。

并發(fā)批處理：并行處理作業(yè)。

分階段的企業(yè)消息驅(qū)動處理。

大規(guī)模并行批處理。

失敗后手動或計(jì)劃重啟。

相關(guān)步驟的順序處理（擴(kuò)展到工作流驅(qū)動的批次）。

部分處理：跳過記錄（例如，在回滾時(shí)）。

整批交易，適用于批量較小或已有存儲過程或腳本的情況。

三、基礎(chǔ)知識

3.1、整體架構(gòu)

3.2、核心接口

ItemReader: is an abstraction that represents the output of a Step, one batch or chunk of items at a time

ItemProcessor:an abstraction that represents the business processing of an item.

ItemWriter: is an abstraction that represents the output of a Step, one batch or chunk of items at a time.

大體即為 輸入→數(shù)據(jù)加工→輸出 ，一個(gè)Job定義多個(gè)Step及處理流程，一個(gè)Step通常涵蓋ItemReader、ItemProcessor、ItemWriter

四、基礎(chǔ)實(shí)操

4.0、引入 SpringBatch

pom 文件引入 springboot

??org.springframework.boot
??spring-boot-starter-parent
??2.2.5.RELEASE
??? 

pom 文件引入 spring-batch 及相關(guān)依賴

????
??????org.springframework.boot
??????spring-boot-starter-batch
????

????
??????org.springframework.boot
??????spring-boot-starter-validation
????

????
??????mysql
??????mysql-connector-java
????

????
??????org.springframework.boot
??????spring-boot-starter-jdbc
????
??

mysql 創(chuàng)建依賴的庫表

sql 腳本的 jar 包路徑：.....maven epositoryorgspringframeworkatchspring-batch-core4.2.1.RELEASEspring-batch-core-4.2.1.RELEASE.jar!orgspringframeworkatchcoreschema-mysql.sql

啟動類標(biāo)志@EnableBatchProcessing

@SpringBootApplication
@EnableBatchProcessing
public?class?SpringBatchStartApplication
{
????public?static?void?main(String[]?args)?{
????????SpringApplication.run(SpringBatchStartApplication.class,?args);
????}
}

FirstJobDemo

@Component
public?class?FirstJobDemo?{

????@Autowired
????private?JobBuilderFactory?jobBuilderFactory;
????@Autowired
????private?StepBuilderFactory?stepBuilderFactory;

????@Bean
????public?Job?firstJob()?{
????????return?jobBuilderFactory.get("firstJob")
????????????????.start(step())
????????????????.build();
????}

????private?Step?step()?{
????????return?stepBuilderFactory.get("step")
????????????????.tasklet((contribution,?chunkContext)?->?{
????????????????????System.out.println("執(zhí)行步驟....");
????????????????????return?RepeatStatus.FINISHED;
????????????????}).build();
????}
}

4.1、流程控制

A、多步驟任務(wù)

@Bean
public?Job?multiStepJob()?{
????return?jobBuilderFactory.get("multiStepJob2")
????????????.start(step1())
????????????.on(ExitStatus.COMPLETED.getExitCode()).to(step2())
????????????.from(step2())
????????????.on(ExitStatus.COMPLETED.getExitCode()).to(step3())
????????????.from(step3()).end()
????????????.build();
}


private?Step?step1()?{
????return?stepBuilderFactory.get("step1")
????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????System.out.println("執(zhí)行步驟一操作。。。");
????????????????return?RepeatStatus.FINISHED;
????????????}).build();
}

private?Step?step2()?{
????return?stepBuilderFactory.get("step2")
????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????System.out.println("執(zhí)行步驟二操作。。。");
????????????????return?RepeatStatus.FINISHED;
????????????}).build();
}

private?Step?step3()?{
????return?stepBuilderFactory.get("step3")
????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????System.out.println("執(zhí)行步驟三操作。。。");
????????????????return?RepeatStatus.FINISHED;
????????????}).build();
}

B、并行執(zhí)行

創(chuàng)建了兩個(gè) Flow：flow1（包含 step1 和 step2）和 flow2（包含 step3）。然后通過JobBuilderFactory的split方法，指定一個(gè)異步執(zhí)行器，將 flow1 和 flow2 異步執(zhí)行（也就是并行）

@Component
public?class?SplitJobDemo?{

????@Autowired
????private?JobBuilderFactory?jobBuilderFactory;
????@Autowired
????private?StepBuilderFactory?stepBuilderFactory;

????@Bean
????public?Job?splitJob()?{
????????return?jobBuilderFactory.get("splitJob")
????????????????.start(flow1())
????????????????.split(new?SimpleAsyncTaskExecutor()).add(flow2())
????????????????.end()
????????????????.build();

????}

????private?Step?step1()?{
????????return?stepBuilderFactory.get("step1")
????????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????????System.out.println("執(zhí)行步驟一操作。。。");
????????????????????return?RepeatStatus.FINISHED;
????????????????}).build();
????}

????private?Step?step2()?{
????????return?stepBuilderFactory.get("step2")
????????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????????System.out.println("執(zhí)行步驟二操作。。。");
????????????????????return?RepeatStatus.FINISHED;
????????????????}).build();
????}

????private?Step?step3()?{
????????return?stepBuilderFactory.get("step3")
????????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????????System.out.println("執(zhí)行步驟三操作。。。");
????????????????????return?RepeatStatus.FINISHED;
????????????????}).build();
????}

????private?Flow?flow1()?{
????????return?new?FlowBuilder("flow1")
????????????????.start(step1())
????????????????.next(step2())
????????????????.build();
????}

????private?Flow?flow2()?{
????????return?new?FlowBuilder("flow2")
????????????????.start(step3())
????????????????.build();
????}
}

C、任務(wù)決策

決策器的作用就是可以指定程序在不同的情況下運(yùn)行不同的任務(wù)流程，比如今天是周末，則讓任務(wù)執(zhí)行 step1 和 step2，如果是工作日，則之心 step1 和 step3。

@Component
public?class?MyDecider?implements?JobExecutionDecider?{
????@Override
????public?FlowExecutionStatus?decide(JobExecution?jobExecution,?StepExecution?stepExecution)?{
????????LocalDate?now?=?LocalDate.now();
????????DayOfWeek?dayOfWeek?=?now.getDayOfWeek();

????????if?(dayOfWeek?==?DayOfWeek.SATURDAY?||?dayOfWeek?==?DayOfWeek.SUNDAY)?{
????????????return?new?FlowExecutionStatus("weekend");
????????}?else?{
????????????return?new?FlowExecutionStatus("workingDay");
????????}
????}
}
@Bean
public?Job?deciderJob()?{
?return?jobBuilderFactory.get("deciderJob")
???.start(step1())
???.next(myDecider)
???.from(myDecider).on("weekend").to(step2())
???.from(myDecider).on("workingDay").to(step3())
???.from(step3()).on("*").to(step4())
???.end()
???.build();
}
private?Step?step1()?{
?return?stepBuilderFactory.get("step1")
???.tasklet((stepContribution,?chunkContext)?->?{
????System.out.println("執(zhí)行步驟一操作。。。");
????return?RepeatStatus.FINISHED;
???}).build();
}

private?Step?step2()?{
?return?stepBuilderFactory.get("step2")
???.tasklet((stepContribution,?chunkContext)?->?{
????System.out.println("執(zhí)行步驟二操作。。。");
????return?RepeatStatus.FINISHED;
???}).build();
}

private?Step?step3()?{
?return?stepBuilderFactory.get("step3")
???.tasklet((stepContribution,?chunkContext)?->?{
????System.out.println("執(zhí)行步驟三操作。。。");
????return?RepeatStatus.FINISHED;
???}).build();
}


private?Step?step4()?{
?return?stepBuilderFactory.get("step4")
???.tasklet((stepContribution,?chunkContext)?->?{
????System.out.println("執(zhí)行步驟四操作。。。");
????return?RepeatStatus.FINISHED;
???}).build();
}
D、任務(wù)嵌套

任務(wù) Job 除了可以由 Step 或者 Flow 構(gòu)成外，我們還可以將多個(gè)任務(wù) Job 轉(zhuǎn)換為特殊的 Step，然后再賦給另一個(gè)任務(wù) Job，這就是任務(wù)的嵌套。

@Component
public?class?NestedJobDemo?{

????@Autowired
????private?JobBuilderFactory?jobBuilderFactory;
????@Autowired
????private?StepBuilderFactory?stepBuilderFactory;
????@Autowired
????private?JobLauncher?jobLauncher;
????@Autowired
????private?JobRepository?jobRepository;
????@Autowired
????private?PlatformTransactionManager?platformTransactionManager;

????//?父任務(wù)
????@Bean
????public?Job?parentJob()?{
????????return?jobBuilderFactory.get("parentJob")
????????????????.start(childJobOneStep())
????????????????.next(childJobTwoStep())
????????????????.build();
????}


????//?將任務(wù)轉(zhuǎn)換為特殊的步驟
????private?Step?childJobOneStep()?{
????????return?new?JobStepBuilder(new?StepBuilder("childJobOneStep"))
????????????????.job(childJobOne())
????????????????.launcher(jobLauncher)
????????????????.repository(jobRepository)
????????????????.transactionManager(platformTransactionManager)
????????????????.build();
????}

????//?將任務(wù)轉(zhuǎn)換為特殊的步驟
????private?Step?childJobTwoStep()?{
????????return?new?JobStepBuilder(new?StepBuilder("childJobTwoStep"))
????????????????.job(childJobTwo())
????????????????.launcher(jobLauncher)
????????????????.repository(jobRepository)
????????????????.transactionManager(platformTransactionManager)
????????????????.build();
????}

????//?子任務(wù)一
????private?Job?childJobOne()?{
????????return?jobBuilderFactory.get("childJobOne")
????????????????.start(
????????????????????stepBuilderFactory.get("childJobOneStep")
????????????????????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????????????????????System.out.println("子任務(wù)一執(zhí)行步驟。。。");
????????????????????????????????return?RepeatStatus.FINISHED;
????????????????????????????}).build()
????????????????).build();
????}

????//?子任務(wù)二
????private?Job?childJobTwo()?{
????????return?jobBuilderFactory.get("childJobTwo")
????????????????.start(
????????????????????stepBuilderFactory.get("childJobTwoStep")
????????????????????????????.tasklet((stepContribution,?chunkContext)?->?{
????????????????????????????????System.out.println("子任務(wù)二執(zhí)行步驟。。。");
????????????????????????????????return?RepeatStatus.FINISHED;
????????????????????????????}).build()
????????????????).build();
????}
}

4.2、讀取數(shù)據(jù)

定義 Model TestData，下面同一

@Data
public?class?TestData?{
????private?int?id;
????private?String?field1;
????private?String?field2;
????private?String?field3;
}

讀取數(shù)據(jù)包含：文本數(shù)據(jù)讀取、數(shù)據(jù)庫數(shù)據(jù)讀取、XML 數(shù)據(jù)讀取、JSON 數(shù)據(jù)讀取等，具體自己查資料。

文本數(shù)據(jù)讀取 Demo

@Component
public?class?FileItemReaderDemo?{

????//?任務(wù)創(chuàng)建工廠
????@Autowired
????private?JobBuilderFactory?jobBuilderFactory;
????//?步驟創(chuàng)建工廠
????@Autowired
????private?StepBuilderFactory?stepBuilderFactory;

????@Bean
????public?Job?fileItemReaderJob()?{
????????return?jobBuilderFactory.get("fileItemReaderJob2")
????????????????.start(step())
????????????????.build();
????}

????private?Step?step()?{
????????return?stepBuilderFactory.get("step")
????????????????.chunk(2)
????????????????.reader(fileItemReader())
????????????????.writer(list?->?list.forEach(System.out::println))
????????????????.build();
????}

????private?ItemReader?fileItemReader()?{
????????FlatFileItemReader?reader?=?new?FlatFileItemReader<>();
????????reader.setResource(new?ClassPathResource("reader/file"));?//?設(shè)置文件資源地址
????????reader.setLinesToSkip(1);?//?忽略第一行

????????//?AbstractLineTokenizer的三個(gè)實(shí)現(xiàn)類之一，以固定分隔符處理行數(shù)據(jù)讀取,
????????//?使用默認(rèn)構(gòu)造器的時(shí)候，使用逗號作為分隔符，也可以通過有參構(gòu)造器來指定分隔符
????????DelimitedLineTokenizer?tokenizer?=?new?DelimitedLineTokenizer();

????????//?設(shè)置屬性名，類似于表頭
????????tokenizer.setNames("id",?"field1",?"field2",?"field3");

????????//?將每行數(shù)據(jù)轉(zhuǎn)換為TestData對象
????????DefaultLineMapper?mapper?=?new?DefaultLineMapper<>();
????????//?設(shè)置LineTokenizer
????????mapper.setLineTokenizer(tokenizer);

????????//?設(shè)置映射方式，即讀取到的文本怎么轉(zhuǎn)換為對應(yīng)的POJO
????????mapper.setFieldSetMapper(fieldSet?->?{
????????????TestData?data?=?new?TestData();
????????????data.setId(fieldSet.readInt("id"));
????????????data.setField1(fieldSet.readString("field1"));
????????????data.setField2(fieldSet.readString("field2"));
????????????data.setField3(fieldSet.readString("field3"));
????????????return?data;
????????});
????????reader.setLineMapper(mapper);
????????return?reader;
????}

}

4.3、輸出數(shù)據(jù)

輸出數(shù)據(jù)也包含：文本數(shù)據(jù)讀取、數(shù)據(jù)庫數(shù)據(jù)讀取、XML 數(shù)據(jù)讀取、JSON 數(shù)據(jù)讀取等

Component
public?class?FileItemWriterDemo?{

????@Autowired
????private?JobBuilderFactory?jobBuilderFactory;
????@Autowired
????private?StepBuilderFactory?stepBuilderFactory;
????@Resource(name?=?"writerSimpleReader")
????private?ListItemReader?writerSimpleReader;

????@Bean
????public?Job?fileItemWriterJob()?throws?Exception?{
????????return?jobBuilderFactory.get("fileItemWriterJob")
????????????????.start(step())
????????????????.build();
????}

????private?Step?step()?throws?Exception?{
????????return?stepBuilderFactory.get("step")
????????????????.chunk(2)
????????????????.reader(writerSimpleReader)
????????????????.writer(fileItemWriter())
????????????????.build();
????}

????private?FlatFileItemWriter?fileItemWriter()?throws?Exception?{
????????FlatFileItemWriter?writer?=?new?FlatFileItemWriter<>();

????????FileSystemResource?file?=?new?FileSystemResource("D:/code/spring-batch-demo/src/main/resources/writer/writer-file");
????????Path?path?=?Paths.get(file.getPath());
????????if?(!Files.exists(path))?{
????????????Files.createFile(path);
????????}
????????//?設(shè)置輸出文件路徑
????????writer.setResource(file);

????????//?把讀到的每個(gè)TestData對象轉(zhuǎn)換為JSON字符串
????????LineAggregator?aggregator?=?item?->?{
????????????try?{
????????????????ObjectMapper?mapper?=?new?ObjectMapper();
????????????????return?mapper.writeValueAsString(item);
????????????}?catch?(JsonProcessingException?e)?{
????????????????e.printStackTrace();
????????????}
????????????return?"";
????????};

????????writer.setLineAggregator(aggregator);
????????writer.afterPropertiesSet();
????????return?writer;
????}

}

4.5、處理數(shù)據(jù)

@Component

public?class?ValidatingItemProcessorDemo?{

????@Autowired
????private?JobBuilderFactory?jobBuilderFactory;
????@Autowired
????private?StepBuilderFactory?stepBuilderFactory;
????@Resource(name?=?"processorSimpleReader")
????private?ListItemReader?processorSimpleReader;

????@Bean
????public?Job?validatingItemProcessorJob()?throws?Exception?{
????????return?jobBuilderFactory.get("validatingItemProcessorJob3")
????????????????.start(step())
????????????????.build();
????}

????private?Step?step()?throws?Exception?{
????????return?stepBuilderFactory.get("step")
????????????????.chunk(2)
????????????????.reader(processorSimpleReader)
????????????????.processor(beanValidatingItemProcessor())
????????????????.writer(list?->?list.forEach(System.out::println))
????????????????.build();
????}

//????private?ValidatingItemProcessor?validatingItemProcessor()?{
//????????ValidatingItemProcessor?processor?=?new?ValidatingItemProcessor<>();
//????????processor.setValidator(value?->?{
//????????????//?對每一條數(shù)據(jù)進(jìn)行校驗(yàn)
//????????????if?("".equals(value.getField3()))?{
//????????????????//?如果field3的值為空串，則拋異常
//????????????????throw?new?ValidationException("field3的值不合法");
//????????????}
//????????});
//????????return?processor;
//????}

????private?BeanValidatingItemProcessor?beanValidatingItemProcessor()?throws?Exception?{
????????BeanValidatingItemProcessor?beanValidatingItemProcessor?=?new?BeanValidatingItemProcessor<>();
????????//?開啟過濾，不符合規(guī)則的數(shù)據(jù)被過濾掉；
//????????beanValidatingItemProcessor.setFilter(true);
????????beanValidatingItemProcessor.afterPropertiesSet();
????????return?beanValidatingItemProcessor;
????}

}

4.6、任務(wù)調(diào)度

可以配合 quartz 或者 xxljob 實(shí)現(xiàn)定時(shí)任務(wù)執(zhí)行

@RestController
@RequestMapping("job")
public?class?JobController?{

????@Autowired
????private?Job?job;
????@Autowired
????private?JobLauncher?jobLauncher;

????@GetMapping("launcher/{message}")
????public?String?launcher(@PathVariable?String?message)?throws?Exception?{
????????JobParameters?parameters?=?new?JobParametersBuilder()
????????????????.addString("message",?message)
????????????????.toJobParameters();
????????//?將參數(shù)傳遞給任務(wù)
????????jobLauncher.run(job,?parameters);
????????return?"success";
????}
}
編輯：黃飛