Spring batch是用来处理大量数据操作的一个框架，主要用来读取大量数据，然后进行一定处理后输出成指定的形式。
Spring batch主要有以下部分组成：
- JobRepository 用来注册job的容器
- JobLauncher 用来启动Job的接口
- Job 实际执行的任务，包含一个或多个Step
- Step step包含ItemReader、ItemProcessor和ItemWriter
- ItemReader 用来读取数据的接口
- ItemProcessor 用来处理数据的接口
- ItemWriter 用来输出数据的接口
以上Spring Batch的主要组成部分只需要注册成Spring的Bean即可。若想开启批处理的支持还需在配置类上使用@EnableBatchProcessing，在Spring Batch中提供了大量的ItemReader和ItemWriter的实现，用来读取不同的数据来源，数据的处理和校验都要通过ItemProcessor接口实现来完成。
Spring Boot的支持
Spring Boot对Spring Batch支持的源码位于org.springframework.boot.autoconfigure.batch下。
Spring Boot为我们自动初始化了Spring Batch存储批处理记录的数据库。
spring batch会自动加载hsqldb驱动，根据需求选择去留。
下面是一个spring boot支持spring batch 的例子：
1. 实体类
1 public class Person {
2
3 @Size(max=4,min=2) //使用JSR-303注解来校验注解
4 private String name;
5
6 private int age;
7
8 private String nation;
9
10 private String address;
11
12 public String getName() {
13 return name;
14 }
15
16 public void setName(String name) {
17 this.name = name;
18 }
19
20 public int getAge() {
21 return age;
22 }
23
24 public void setAge(int age) {
25 this.age = age;
26 }
27
28 public String getNation() {
29 return nation;
30 }
31
32 public void setNation(String nation) {
33 this.nation = nation;
34 }
35
36 public String getAddress() {
37 return address;
38 }
39
40 public void setAddress(String address) {
41 this.address = address;
42 }
43 }
2. 校验器
1 public class CsvBeanValidator<T> implements Validator<T>,InitializingBean {
2 private javax.validation.Validator validator;
3 @Override
4 public void afterPropertiesSet() throws Exception { //使用JSR-303的Validator来校验我们的数据，在此处进行JSR-303的Validator的初始化
5 ValidatorFactory validatorFactory = Validation.buildDefaultValidatorFactory();
6 validator = validatorFactory.usingContext().getValidator();
7 }
8
9 @Override
10 public void validate(T value) throws ValidationException {
11 Set<ConstraintViolation<T>> constraintViolations = validator.validate(value); //使用Validator的validate方法校验数据
12 if(constraintViolations.size()>0){
13
14 StringBuilder message = new StringBuilder();
15 for (ConstraintViolation<T> constraintViolation : constraintViolations) {
16 message.append(constraintViolation.getMessage() + "\n");
17 }
18 throw new ValidationException(message.toString());
19
20 }
21
22 }
23
24 }
3. ItemProcessor
1 public class CsvItemProcessor extends ValidatingItemProcessor<Person>{
2
3 @Override
4 public Person process(Person item) throws ValidationException {
5 super.process(item); //需要执行super.process(item)才会调用自定义校验器
6
7 if(item.getNation().equals("汉族")){ //对数据做简单的处理，若民族为汉族，则数据转换成01，其余转换成02
8 item.setNation("01");
9 }else{
10 item.setNation("02");
11 }
12 return item;
13 }
14
15
16 }
4. Job监听（监听器要实现JobExecutionListener接口，并重写其beforeJob、afterJob方法即可）
1 public class CsvJobListener implements JobExecutionListener{
2
3 long startTime;
4 long endTime;
5 @Override
6 public void beforeJob(JobExecution jobExecution) {
7 startTime = System.currentTimeMillis();
8 System.out.println("任务处理开始");
9 }
10
11 @Override
12 public void afterJob(JobExecution jobExecution) {
13 endTime = System.currentTimeMillis();
14 System.out.println("任务处理结束");
15 System.out.println("耗时:" + (endTime - startTime) + "ms");
16 }
17
18 }
5. 配置
1 @Configuration
2 @EnableBatchProcessing
3 public class CsvBatchConfig {
4
5 @Bean
6 public ItemReader<Person> reader() throws Exception {
7 FlatFileItemReader<Person> reader = new FlatFileItemReader<Person>(); //使用FlatFileItemReader读取文件
8 reader.setResource(new ClassPathResource("people.csv")); //使用FlatFileItemReader的setResource方法设置CSV文件的路径
9 reader.setLineMapper(new DefaultLineMapper<Person>() {{ //在此处对CVS文件的数据和领域模型类做对应映射
10 setLineTokenizer(new DelimitedLineTokenizer() {{
11 setNames(new String[] { "name","age", "nation" ,"address"});
12 }});
13 setFieldSetMapper(new BeanWrapperFieldSetMapper<Person>() {{
14 setTargetType(Person.class);
15 }});
16 }});
17 return reader;
18 }
19
20 @Bean
21 public ItemProcessor<Person, Person> processor() {
22 CsvItemProcessor processor = new CsvItemProcessor(); //使用自定义的ItemProcessor的实现
23 processor.setValidator(csvBeanValidator()); //为Processor指定校验器
24 return processor;
25 }
26
27
28
29 @Bean
30 public ItemWriter<Person> writer(DataSource dataSource) {//Spring能让容器中已有的Bean以参数的形式注入，Spring boot已经定义了DataSource
31 JdbcBatchItemWriter<Person> writer = new JdbcBatchItemWriter<Person>(); //使用JDBC批处理的JdbcBatchItemWriter来写数据到数据库
32 writer.setItemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<Person>());
33 String sql = "insert into person " + "(id,name,age,nation,address) "
34 + "values(hibernate_sequence.nextval, :name, :age, :nation,:address)";
35 writer.setSql(sql); //在此设置要执行批处理的sql语句
36 writer.setDataSource(dataSource);
37 return writer;
38 }
39
40 @Bean
41 public JobRepository jobRepository(DataSource dataSource, PlatformTransactionManager transactionManager)
42 throws Exception {
43 JobRepositoryFactoryBean jobRepositoryFactoryBean = new JobRepositoryFactoryBean();
44 jobRepositoryFactoryBean.setDataSource(dataSource);
45 jobRepositoryFactoryBean.setTransactionManager(transactionManager);
46 jobRepositoryFactoryBean.setDatabaseType("oracle");
47 return jobRepositoryFactoryBean.getObject();
48 }
49
50 @Bean
51 public SimpleJobLauncher jobLauncher(DataSource dataSource, PlatformTransactionManager transactionManager)
52 throws Exception {
53 SimpleJobLauncher jobLauncher = new SimpleJobLauncher();
54 jobLauncher.setJobRepository(jobRepository(dataSource, transactionManager));
55 return jobLauncher;
56 }
57
58 @Bean
59 public Job importJob(JobBuilderFactory jobs, Step s1) {
60 return jobs.get("importJob")
61 .incrementer(new RunIdIncrementer())
62 .flow(s1) //指定step
63 .end()
64 .listener(csvJobListener()) //绑定监听器
65 .build();
66 }
67
68 @Bean
69 public Step step1(StepBuilderFactory stepBuilderFactory, ItemReader<Person> reader, ItemWriter<Person> writer,
70 ItemProcessor<Person,Person> processor) {
71 return stepBuilderFactory
72 .get("step1")
73 .<Person, Person>chunk(65000) //批处理每次提交65000条数据
74 .reader(reader) //给step绑定reader
75 .processor(processor) //给step绑定Processor
76 .writer(writer) //给step绑定writer
77 .build();
78 }
79
80
81
82 @Bean
83 public CsvJobListener csvJobListener() {
84 return new CsvJobListener();
85 }
86
87 @Bean
88 public Validator<Person> csvBeanValidator() {
89 return new CsvBeanValidator<Person>();
90 }
91
92
93 }
6.application.xml
1 spring.datasource.driverClassName=oracle.jdbc.OracleDriver
2 spring.datasource.url=jdbc\:oracle\:thin\:@localhost\:1521\:xe
3 spring.datasource.username=boot
4 spring.datasource.password=boot
5
6 spring.batch.job.enabled=true
7
8 logging.level.org.springframework.web = DEBUG
上面的例子是自动触发批处理的，当我们需要手动触发批处理时，需要将CsvBatchConfig类的@Configuration注解注释掉，让此配置类不再起效，新建TriggerBatchConfig配置类，内容与CsvBatchConfig完全一致，除了修改定义ItemReader这个Bean;另外，还需要修改application.xml配置文件spring.batch.job.enable=false
1 @Configuration
2 @EnableBatchProcessing
3 public class TriggerBatchConfig {
4
5 @Bean
6 @StepScope
7 public FlatFileItemReader<Person> reader(@Value("#{jobParameters['input.file.name']}") String pathToFile) throws Exception {
8 FlatFileItemReader<Person> reader = new FlatFileItemReader<Person>(); //
9 reader.setResource(new ClassPathResource(pathToFile)); //
10 reader.setLineMapper(new DefaultLineMapper<Person>() {{ //
11 setLineTokenizer(new DelimitedLineTokenizer() {{
12 setNames(new String[] { "name","age", "nation" ,"address"});
13 }});
14 setFieldSetMapper(new BeanWrapperFieldSetMapper<Person>() {{
15 setTargetType(Person.class);
16 }});
17 }});
18
19 return reader;
20 }
21
22 @Bean
23 public ItemProcessor<Person, Person> processor() {
24 CsvItemProcessor processor = new CsvItemProcessor();
25 processor.setValidator(csvBeanValidator());
26 return processor;
27 }
28
29
30
31 @Bean
32 public ItemWriter<Person> writer(DataSource dataSource) {
33 JdbcBatchItemWriter<Person> writer = new JdbcBatchItemWriter<Person>();
34 writer.setItemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<Person>());
35 String sql = "insert into person " + "(id,name,age,nation,address) "
36 + "values(hibernate_sequence.nextval, :name, :age, :nation,:address)";
37 writer.setSql(sql); //3
38 writer.setDataSource(dataSource);
39 return writer;
40 }
41
42 @Bean
43 public JobRepository jobRepository(DataSource dataSource, PlatformTransactionManager transactionManager)
44 throws Exception {
45 JobRepositoryFactoryBean jobRepositoryFactoryBean = new JobRepositoryFactoryBean();
46 jobRepositoryFactoryBean.setDataSource(dataSource);
47 jobRepositoryFactoryBean.setTransactionManager(transactionManager);
48 jobRepositoryFactoryBean.setDatabaseType("oracle");
49 return jobRepositoryFactoryBean.getObject();
50 }
51
52 @Bean
53 public SimpleJobLauncher jobLauncher(DataSource dataSource, PlatformTransactionManager transactionManager)
54 throws Exception {
55 SimpleJobLauncher jobLauncher = new SimpleJobLauncher();
56 jobLauncher.setJobRepository(jobRepository(dataSource, transactionManager));
57 return jobLauncher;
58 }
59
60 @Bean
61 public Job importJob(JobBuilderFactory jobs, Step s1) {
62 return jobs.get("importJob")
63 .incrementer(new RunIdIncrementer())
64 .flow(s1)
65 .end()
66 .listener(csvJobListener())
67 .build();
68 }
69
70 @Bean
71 public Step step1(StepBuilderFactory stepBuilderFactory, ItemReader<Person> reader, ItemWriter<Person> writer,
72 ItemProcessor<Person,Person> processor) {
73 return stepBuilderFactory
74 .get("step1")
75 .<Person, Person>chunk(65000)
76 .reader(reader)
77 .processor(processor)
78 .writer(writer)
79 .build();
80 }
81
82
83
84 @Bean
85 public CsvJobListener csvJobListener() {
86 return new CsvJobListener();
87 }
88
89 @Bean
90 public Validator<Person> csvBeanValidator() {
91 return new CsvBeanValidator<Person>();
92 }
93
94
95 }
控制层代码
1 @RestController
2 public class DemoController {
3
4 @Autowired
5 JobLauncher jobLauncher;
6
7 @Autowired
8 Job importJob;
9 public JobParameters jobParameters;
10
11 @RequestMapping("/read")
12 public String imp(String fileName) throws Exception{
13
14 String path = fileName+".csv";
15 jobParameters = new JobParametersBuilder()
16 .addLong("time", System.currentTimeMillis())
17 .addString("input.file.name", path)
18 .toJobParameters();
19 jobLauncher.run(importJob,jobParameters);
20 return "ok";
21 }
22
23 }
