Spring Boot - Configure Multiple DBs (In Progress)

 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")

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