Spring batch – using two data source in one step - spring

Question

Currently my spring-batch-app is configured to use only one data source (properties file). When running the app spring will pick the default configuration.
spring.datasource.url=jdbc:sqlserver ...
spring.datasource.driverClassName=com.microsoft.sqlserver.jdbc.SQLServerDriver
spring.jpa.show-sql=true
spring.jpa.generate-ddl=false
spring.jpa.hibernate.ddl-auto=none
spring.jpa.hibernate.naming.physical-
strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.SQLServer2012Dialect
I have a task to create a job which required some data from another database. Basically the step will retrieve data from one data source and write the data to another data source.
For the new data source I have created a bean:
#Bean
public DataSource melDataSource() {
DriverManagerDataSource melDataSource = new DriverManagerDataSource();
melDataSource.setDriverClassName("prestosql....");
melDataSource.setUrl("....");
melDataSource.setUsername("....");
melDataSource.setPassword("....");
return melDataSource;
}
And this is how I am calling the dataSource:
#Autowired
private DataSource dataSource;
#Autowired
private DataSource melDataSource;
When running the program I get the following error:
Error creating bean with name
'org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration': Unsatisfied
dependency expressed through field 'dataSource'; nested exception is
org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name
'melDataSource': Requested bean is currently in creation: Is there an unresolvable circular
reference?
How can I add another data source ?
Thank you

Answer 1

You need to move your data source bean declaration in a separate class and import that class in your batch configuration class. Something like:
class DataSourceConfiguration {
#Bean
public DataSource melDataSource() {
DriverManagerDataSource melDataSource = new DriverManagerDataSource();
melDataSource.setDriverClassName("prestosql....");
melDataSource.setUrl("....");
melDataSource.setUsername("....");
melDataSource.setPassword("....");
return melDataSource;
}
}
#Configuration
#Import(DataSourceConfiguration.class)
class BatchConfiguration {
// use datasource bean here
}