Spring Batch: datasource for Batch and datasource for step

Question

I need to get access to two datasources:

• Spring batch repository: in memory H2
• My step needs to get access to a mssql.

I've seen several example over there about how to create a custom batch configurer.

However, sometimes:

1. implements BatchConfigurer
2. extends DefaultBatchConfigurer

Currently, my configuration files are:

.
├── steps
│  └── MssqlBatchConfigurationStep.java
└── MainJobBatchConfiguration.java

My step configuration is:

@Configuration
public class MssqlBatchConfigurationStep {
 private DataSource dataSource;
 /**
 *
 * @param dataSource
 */
 public MssqlBatchConfigurationStep(DataSource dataSource) {
 this.dataSource = dataSource;
 }
 /**
 *
 * @return
 */
 public ItemReader<Unitat> reader() {
 String sql = "SELECT operation,update_time,table_name,rowid,user_login,user_name, user_ip,application_name,application_version,new_value,old_value FROM renovastorage.data_log";
 JdbcCursorItemReader<Unitat> jdbcCursorItemReader = new JdbcCursorItemReader<>();
 jdbcCursorItemReader.setDataSource(this.dataSource);
 jdbcCursorItemReader.setSql(sql);
 jdbcCursorItemReader.setVerifyCursorPosition(false);
 jdbcCursorItemReader.setRowMapper(new UnitatRowMapper());
 return jdbcCursorItemReader;
 }
 /**
 *
 * @return
 */
 public ItemWriter<UnitatDenormalized> writer() {
 // write to solr
 return null;
 }
}

The problem here is that, this step is getting default datasource. This datasource is the same that is got by Spring Batch.

In order to solve that, I want to create a "Batch Configurer" in order to get specific datasource instead of the default one.

Here you can see my job configuration:

@Configuration
@EnableBatchProcessing
// @EnableScheduling
public class MainJobBatchConfiguration {
 private JobBuilderFactory jobBuilderFactory;
 private StepBuilderFactory stepBuilderFactory;
 private MssqlBatchConfigurationStep unitatBatchStep;
 /**
 *
 * @param jobBuilderFactory
 * @param stepBuilderFactory
 */
 public MainJobBatchConfiguration(
 JobBuilderFactory jobBuilderFactory,
 StepBuilderFactory stepBuilderFactory,
 MssqlBatchConfigurationStep unitatBatchStep
 ) {
 this.jobBuilderFactory = jobBuilderFactory;
 this.stepBuilderFactory = stepBuilderFactory;
 this.unitatBatchStep = unitatBatchStep;
 }
 /**
 *
 * @return
 */
 @Bean
 public Step step() {
 return this.stepBuilderFactory
 .get("mssql")
 .<Unitat, UnitatDenormalized>chunk(10)
 .reader(this.unitatBatchStep.reader())
 .writer(this.unitatBatchStep.writer())
 .build();
 }
 /**
 *
 * @param step
 * @return
 */
 @Bean
 public Job job(Step step) {
 Job job = this.jobBuilderFactory.get("job1")
 .flow(step)
 .end()
 .build();
 return job;
 }
}

• Mahmoud Ben Hassine: If the answer here stackoverflow.com/a/64871325/5019386 helped, please accept it.

Answer 1

You need to add a secondary datasource bean and autowire that datasource.

application.properties

spring.second-datasource.url = [url]
spring.second-datasource.username = [username]
spring.second-datasource.password = [password]
spring.second-datasource.driverClassName= [driverClassName]

Datasource config

 @Primary
 @Bean(value = "defaultDataSource")
 @ConfigurationProperties(prefix = "spring.datasource")
 public DataSource datasource() {
 DriverManagerDataSource dataSource = new DriverManagerDataSource();
 return dataSource;
 }
 @Bean(value = "secondDataSource")
 @ConfigurationProperties(prefix = "spring.second-datasource")
 public DataSource ticketDataSource() {
 DriverManagerDataSource dataSource = new DriverManagerDataSource();
 return dataSource;
 }

Autowire secondDataSource in your reader.

 private DataSource dataSource;
 /**
 *
 * @param dataSource
 */
 public MssqlBatchConfigurationStep(@Qualifier("secondDataSource") DataSource dataSource) {
 this.dataSource = dataSource;
 }

Answer 2

My step needs to get access to a mssql.

In order to solve that, I want to create a "Batch Configurer" in order to get specific datasource instead of the default one.

In order to solve that, I would instead add a qualifier on the datasource to specify which one should be used in the step:

@Configuration
public class MssqlBatchConfigurationStep {
 private DataSource dataSource;
 /**
 *
 * @param dataSource
 */
 public MssqlBatchConfigurationStep(@Qualifier("YOUR_MSSQL_DATASOURCE_BEAN_NAME") DataSource dataSource) {
 this.dataSource = dataSource;
 }
}

With that, your reader should be pointing to the mssql datasource and read data from it.