环境:Springboot2.4.12 + Spring Batch4.2.7
Spring Batch是一个轻量级的,完全面向Spring的批处理框架,可以应用于企业级大量的数据处理系统。Spring Batch以POJO和大家熟知的Spring框架为基础,使开发者更容易的访问和利用企业级服务。Spring Batch可以提供大量的,可重复的数据处理功能,包括日志记录/跟踪,事务管理,作业处理统计工作重新启动、跳过,和资源管理等重要功能。
业务场景:
技术目标:
Spring Batch的结构:
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此分层体系结构突出了三个主要的高级组件:应用程序、核心和基础架构。该应用程序包含开发人员使用SpringBatch编写的所有批处理作业和自定义代码。批处理核心包含启动和控制批处理作业所需的核心运行时类。它包括JobLauncher、Job和Step的实现。应用程序和核心都构建在公共基础架构之上。此基础结构包含公共读写器和服务(如RetryTemplate),应用程序开发人员(读写器,如ItemReader和ItemWriter)和核心框架本身(retry,它是自己的库)都使用这些服务。
下面介绍开发流程
本例完成 读取文件内容,经过处理后,将数据保存到数据库中
org.springframework.boot
spring-boot-starter-batch
org.springframework.boot
spring-boot-starter-web
org.springframework.boot
spring-boot-starter-data-jpa
mysql
mysql-connector-java
org.hibernate
hibernate-validator
6.0.7.Final
spring:
datasource:
driverClassName: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/batch?serverTimeznotallow=GMT%2B8
username: root
password: *******
type: com.zaxxer.hikari.HikariDataSource
hikari:
minimumIdle: 10
maximumPoolSize: 200
autoCommit: true
idleTimeout: 30000
poolName: MasterDatabookHikariCP
maxLifetime: 1800000
connectionTimeout: 30000
connectionTestQuery: SELECT 1
---
spring:
jpa:
generateDdl: false
hibernate:
ddlAuto: update
openInView: true
show-sql: true
---
spring:
batch:
job:
enabled: false #是否自动执行任务
initialize-schema: always #自动为我们创建数据库脚本@Configuration
@EnableBatchProcessing
public class BatchConfig extends DefaultBatchConfigurer{
}接着上一步的配置类BatchConfig重写对应方法
@Override
protected JobLauncher createJobLauncher() throws Exception {
SimpleJobLauncher jobLauncher = new SimpleJobLauncher();
jobLauncher.setJobRepository(createJobRepository());
jobLauncher.afterPropertiesSet();
return jobLauncher;
}接着上一步的配置类BatchConfig重写对应方法
@Resource
private PlatformTransactionManager transactionManager ;
@Override
protected JobRepository createJobRepository() throws Exception {
JobRepositoryFactoryBean factory = new JobRepositoryFactoryBean();
factory.setDatabaseType("mysql");
factory.setTransactionManager(transactionManager);
factory.setDataSource(dataSource);
factory.afterPropertiesSet();
return factory.getObject();
}@Bean
public Job myJob(JobBuilderFactory builder, @Qualifier("myStep")Step step){
return builder.get("myJob")
.incrementer(new RunIdIncrementer())
.flow(step)
.end()
.listener(jobExecutionListener)
.build();
}@Bean
public ItemReader reader(){
FlatFileItemReader reader = new FlatFileItemReader<>();
reader.setResource(new ClassPathResource("cvs/persons.cvs"));
reader.setLineMapper(new DefaultLineMapper() {
// 代码块
{
setLineTokenizer(new DelimitedLineTokenizer(",") {
{
setNames("id", "name");
}
}) ;
setFieldSetMapper(new BeanWrapperFieldSetMapper() {
{
setTargetType(Person.class) ;
}
});
}
});
return reader;
} @Bean
public ItemProcessor processorPerson(){
return new ItemProcessor() {
@Override
public Person2 process(Person item) throws Exception {
Person2 p = new Person2() ;
p.setId(item.getId()) ;
p.setName(item.getName() + ", pk");
return p ;
}
} ;
} @Resource
private Validator validator ;
@Resource
private EntityManagerFactory entityManagerFactory ;
@Bean
public ItemWriter writerPerson(){
JpaItemWriter writer = null ;
JpaItemWriterBuilder builder = new JpaItemWriterBuilder<>() ;
builder.entityManagerFactory(entityManagerFactory) ;
writer = builder.build() ;
return writer;
} @Bean
public Step myStep(StepBuilderFactory stepBuilderFactory, ItemReader reader, ItemWriter writer, ItemProcessor processor){
return stepBuilderFactory
.get("myStep")
.chunk(2) // Chunk的机制(即每次读取一条数据,再处理一条数据,累积到一定数量后再一次性交给writer进行写入操作)
.reader(reader).faultTolerant().retryLimit(3).retry(Exception.class).skip(Exception.class).skipLimit(2)
.listener(new MyReadListener())
.processor(processor)
.writer(writer).faultTolerant().skip(Exception.class).skipLimit(2)
.listener(new MyWriteListener())
.build();
} public class MyReadListener implements ItemReadListener {
private Logger logger = LoggerFactory.getLogger(MyReadListener.class);
@Override
public void beforeRead() {
}
@Override
public void afterRead(Person item) {
System.out.println("reader after: " + Thread.currentThread().getName()) ;
}
@Override
public void onReadError(Exception ex) {
logger.info("读取数据错误:{}", ex);
}
} @Component
public class MyWriteListener implements ItemWriteListener {
private Logger logger = LoggerFactory.getLogger(MyWriteListener.class);
@Override
public void beforeWrite(List extends Person> items) {
}
@Override
public void afterWrite(List extends Person> items) {
System.out.println("writer after: " + Thread.currentThread().getName()) ;
}
@Override
public void onWriteError(Exception exception, List extends Person> items) {
try {
logger.info(format("%s%n", exception.getMessage()));
for (Person item : items) {
logger.info(format("Failed writing BlogInfo : %s", item.toString()));
}
} catch (Exception e) {
e.printStackTrace();
}
}
} person.cvs文件内容
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实体类:
@Entity
@Table(name = "t_person")
public class Person {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id ;
private String name ;
}启动任务执行
@RestController
@RequestMapping("/demo")
public class DemoController {
@Resource
@Qualifier("myJob")
private Job job ;
@Resource
private JobLauncher launcher ;
@GetMapping("/index")
public Object index() {
JobParameters jobParameters = new JobParametersBuilder().toJobParameters() ;
try {
launcher.run(job, jobParameters) ;
} catch (JobExecutionAlreadyRunningException | JobRestartException | JobInstanceAlreadyCompleteException
| JobParametersInvalidException e) {
e.printStackTrace();
}
return "success" ;
}
}启动服务,自动为我们创建了表
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查看表情况
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