Update 2022-05-29 with Spring Boot 1.5.8.RELEASE which should work with Spring Boot 2.x
Most answers do not provide how to use them (as datasource itself and as transaction), only how to config them.
Moreover you should know how to commit/rollback transactions of both datasources at the same time.
You can see the runnable example and some explanation in https://github.com/surasint/surasint-examples/tree/master/spring-boot-jdbi/10_spring-boot-two-databases (see what you can try in README.txt)
I copied some code here.
First you have to set application.properties like this
#Database
database1.datasource.url=jdbc:mysql://localhost/testdb
database1.datasource.username=root
database1.datasource.password=root
database1.datasource.driver-class-name=com.mysql.jdbc.Driver
database2.datasource.url=jdbc:mysql://localhost/testdb2
database2.datasource.username=root
database2.datasource.password=root
database2.datasource.driver-class-name=com.mysql.jdbc.Driver
Then define them as providers (@Bean) like this:
@Bean(name = "datasource1")
@ConfigurationProperties("database1.datasource")
@Primary
public DataSource dataSource(){
return DataSourceBuilder.create().build();
}
@Bean(name = "datasource2")
@ConfigurationProperties("database2.datasource")
public DataSource dataSource2(){
return DataSourceBuilder.create().build();
}
Note that I have @Bean(name="datasource1") and @Bean(name="datasource2"), then you can use it when we need datasource as @Qualifier("datasource1") and @Qualifier("datasource2") , for example
@Qualifier("datasource1")
@Autowired
private DataSource dataSource;
If you do care about transaction, you have to define DataSourceTransactionManager for both of them, like this:
@Bean(name="tm1")
@Autowired
@Primary
DataSourceTransactionManager tm1(@Qualifier ("datasource1") DataSource datasource) {
DataSourceTransactionManager txm = new DataSourceTransactionManager(datasource);
return txm;
}
@Bean(name="tm2")
@Autowired
DataSourceTransactionManager tm2(@Qualifier ("datasource2") DataSource datasource) {
DataSourceTransactionManager txm = new DataSourceTransactionManager(datasource);
return txm;
}
Then you can use it like
@Transactional //this will use the first datasource because it is @primary
or
@Transactional("tm2")
The most important part, which you will hardly find an example in anywhere: if you want a method to commit/rollback transactions of both databases, you need ChainedTransactionManager for tm1 and tm2 , like this:
@Bean(name = "chainedTransactionManager")
public ChainedTransactionManager getChainedTransactionManager(@Qualifier ("tm1") DataSourceTransactionManager tm1, @Qualifier ("tm2") DataSourceTransactionManager tm2){
return new ChainedTransactionManager(tm1, tm2);
}
To use it, add this annotation in a method @Transactional(value="chainedTransactionManager") for example
@Transactional(value="chainedTransactionManager")
public void insertAll() {
UserBean test = new UserBean();
test.setUsername("username" + new Date().getTime());
userDao.insert(test);
userDao2.insert(test);
}
This should be enough. See example and detail in the link above.
