\u00a0Spring Batch Job<\/b><\/h2>\n
Spring batch job reads input data, processes the input data, and writes the processed data to the configured output.<\/span><\/p>\n <\/p>\n Spring Batch job consists of the following components as shown in above image:<\/span><\/p>\n The following figure define a simple batch job<\/p>\n <\/p>\n Above image describe a job only, not a batch job. Let us try to visualize a batch job with following image:<\/span><\/p>\n <\/p>\n Now, the above diagram is a better description of a batch job which includes multiple jobs. When all jobs are done then the batch can be declared as done.<\/span><\/p>\n What we\u2019ll build<\/strong><\/p>\n We will build a job that will read a string value from an array, convert it into upper case and print on console.<\/span><\/p>\n This job will perform its task in one step and this step will have a reader that will read a string value from an array, a processor that will transform a string value in uppercase and a writer that will print transformed string on console.<\/span><\/p>\n What we\u2019ll need<\/b><\/p>\n 1. Required dependencies<\/b><\/p>\n Add these dependencies<\/span><\/p>\n <\/p>\n <\/p>\n Although we can make WAR file of batch processing ,but here we are making\u00a0 a standalone application, in this approach we package everything in a single, executable JAR file and run as a\u00a0standalone application.<\/p>\n In SprinpBatchApplication<\/em> class, @EnableBatchProcessing is used to include Spring Batch features and provide a configuration for setting up batch jobs in a @Configuration class.<\/span><\/p>\n<\/div>\n<\/div>\n Create a configuration file and enable Spring batch via annotations: <\/span>@Configuration<\/span><\/em><\/p>\n We will build a single executable JAR\u00a0 that contains all the required dependencies, classes, and resources.<\/p>\n\u00a0 Spring Batch Job processing<\/b><\/h4>\n
![\"\"](\"https:\/\/www.innovationm.com\/blog\/wp-content\/uploads\/2018\/03\/Image-3-Aakash.png\")
<\/p>\n\n
![\"\"](\"https:\/\/www.innovationm.com\/blog\/wp-content\/uploads\/2018\/03\/Image-1-Aakash.png\")
<\/p>\n![\"\"](\"https:\/\/www.innovationm.com\/blog\/wp-content\/uploads\/2018\/03\/Image-2-Aakash.png\")
<\/p>\n<\/h2>\n
Example Of\u00a0<\/span>Spring Batch<\/span><\/h2>\n
\n
<project xmlns=\"http:\/\/maven.apache.org\/POM\/4.0.0\" \r\nxmlns:xsi=\"http:\/\/www.w3.org\/2001\/XMLSchema-instance\" \r\n xsi:schemaLocation=\"http:\/\/maven.apache.org\/POM\/4.0.0 \r\nhttp:\/\/maven.apache.org\/xsd\/maven-4.0.0.xsd\">\r\n\r\n<project>\r\n<dependency>\r\n\t<groupId>org.springframework.boot<\/groupId>\r\n\t<artifactId>spring-boot-starter-web<\/artifactId>\r\n<\/dependency>\r\n<dependency>\r\n\t<groupId>org.springframework.boot<\/groupId>\r\n\t<artifactId>spring-boot-starter-test<\/artifactId>\r\n\t<scope>test<\/scope>\r\n<\/dependency>\r\n<dependency>\r\n <groupId>org.springframework.boot<\/groupId>\r\n <artifactId>spring-boot-starter-batch<\/artifactId>\r\n<\/dependency>\r\n\r\n<\/project><\/pre>\n
2.<\/strong>\u00a0Create Steps: Reader, Processor and Writer<\/b><\/h4>\n
\n
public class ReaderImpl implements ItemReader<String>{\r\n\tprivate String[] msgArray= {\"Hi\",\"Welcome\",\"To\",\"Spring\",\"batch\",\"!!\"};\r\n\tprivate int count=0;\r\n\t@Override\r\n\tpublic String read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {\t\r\n\t\tif(count < msgArray.length){\r\n\t\t\treturn msgArray[count++];\r\n\t\t}else{\r\n\t\t\tcount=0;\r\n\t\t}\r\n\t\treturn null;\r\n\t}\r\n}\r\n<\/pre>\n\n
public class ProcessorImpl implements ItemProcessor<String, String>{\r\n\t@Override\r\n\tpublic String process(String message) throws Exception {\r\n\t\treturn message.toUpperCase();\r\n\t}\r\n}\r\n<\/pre>\n\n
public class WriterImpl implements ItemWriter<String> {\r\n\t@Override\r\n\tpublic void write(List<? extends String> msgArray) throws Exception {\r\n\t\tfor(String msg : msgArray){\r\n\t\t\tSystem.out.println(\"In writer: \" + msg);\r\n\t\t}\r\n\t}\r\n}\r\n<\/pre>\n3.\u00a0<\/b>Make the application executable<\/h4>\n
@SpringBootApplication\r\n@EnableBatchProcessing\r\npublic class SprinpBatchApplication {\r\n\tpublic static void main(String[] args) {\r\n\t\tSpringApplication.run(SprinpBatchApplication.class, args);\r\n\t}\r\n}\r\n<\/pre>\n4.<\/b>Spring Batch Configuration <\/b><\/h4>\n
@Configuration\r\npublic class BatchConfig {\r\n @Autowired\r\n public JobBuilderFactory jobBuilderFactory;\r\n @Autowired\r\n public StepBuilderFactory stepBuilderFactory;\r\n\r\n@Autowired\r\nprivate SimpleJobLauncher jobLauncher;\r\n \r\n@Scheduled(cron = \"0 0 8 1\/1 * ?\")\t\r\npublic void sendSmsForExpiringBookmark() throws Exception \r\n{\r\nSystem.out.println(\" Job Started at :\"+ new Date());\r\nJobParameters param = new JobParametersBuilder().addString(\"JobID\",\r\nString.valueOf(System.currentTimeMillis())).toJobParameters();\r\nJobExecution execution = jobLauncher.run(job(), param);\r\nSystem.out.println(\"Job finished with status :\" + execution.getStatus());\r\n} \r\n public Job job() {\r\n return jobBuilderFactory.get(\"job\")\r\n .incrementer(new RunIdIncrementer())\r\n .flow(step1())\r\n .end()\r\n .build();\r\n }\r\n\r\n \r\n public Step step1() {\r\n return stepBuilderFactory.get(\"step1\")\r\n .<String, String> chunk(1)\r\n .reader(new Reader())\r\n .processor(new Processor())\r\n .writer(new Writer())\r\n .build();\r\n }\r\n<\/pre>\n5. Spring Batch Job Configuration <\/strong><\/h4>\n
@Configuration\r\n@EnableScheduling\r\npublic class BatchScheduler {\r\n\r\n\t@Bean\r\n\tpublic ResourcelessTransactionManager transactionManager() {\r\n\t\treturn new ResourcelessTransactionManager();\r\n\t}\r\n\r\n\t@Bean\r\n\tpublic MapJobRepositoryFactoryBean mapJobRepositoryFactory(\r\n\tResourcelessTransactionManager txManager) throws Exception {\r\n\tMapJobRepositoryFactoryBean factory = new MapJobRepositoryFactoryBean(\r\n\t\t\t\ttxManager);\r\n\t\tfactory.afterPropertiesSet();\r\n\t\treturn factory;\r\n\t}\r\n\t\r\n @Bean\r\n\tpublic JobRepository jobRepository(MapJobRepositoryFactoryBean factory)\r\n\t\t\tthrows Exception {\r\n\t\treturn (JobRepository) factory.getObject();\r\n\t}\r\n\r\n\t@Bean\r\n\tpublic SimpleJobLauncher jobLauncher(JobRepository jobRepository) {\r\n\t\tSimpleJobLauncher launcher = new SimpleJobLauncher();\r\n\t\tlauncher.setJobRepository(jobRepository);\r\n\t\treturn launcher;\r\n\t}\r\n\r\n}\r\n<\/pre>\n6.Build an executable JAR file of Batch Job<\/h4>\n