<!-- Property file located in the legacy application's folder -->
<context:property-placeholder location="file:///D:/config.properties" />

<!-- Shared data source properties are read from the config.properties file -->
<bean id="parentDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource" abstract="true">
    <property name="driverClassName" value="${db.driver}" />
    <property name="username" value="${db.user}" />
    <property name="password" value="${db.password}" />
</bean>

<!-- Database urls by year -->
<bean id="Year2012DataSource" parent="parentDataSource">
    <property name="url" value="jdbc:sqlserver://localhost;databaseName=DbName_v570_2012" />
</bean>
<bean id="Year2011DataSource" parent="parentDataSource">
    <property name="url" value="jdbc:sqlserver://localhost;databaseName=DbName_v570_2011" />
</bean>
<bean id="Year2010DataSource" parent="parentDataSource">
    <property name="url" value="jdbc:sqlserver://localhost;databaseName=DbName_v570_2010" />
</bean>
<!-- ... and so on, these should instead be populated dynamically ... -->

<!-- DbConnectionRoutingDataSource extends AbstractRoutingDataSource -->
<bean id="dataSource" class="someProject.DbConnectionRoutingDataSource">
    <property name="targetDataSources">
        <map key-type="int">
            <entry key="2011" value-ref="Year2011DataSource" />
            <entry key="2010" value-ref="Year2010DataSource" />
            <!-- ... and so on, these also should instead be populated dynamically ... -->
        </map>
    </property>
    <property name="defaultTargetDataSource" ref="Year2012DataSource" />
</bean>

class MyDatasourceRegisteringBeanFactoryPostProcessor implements BeanFactoryPostProcessor {

    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
        //Read in details from legacy properties.. build custom bean definitions and register with bean factory
        //for each legacy property...
            BeanDefinitionBuilder datasourceDefinitionBuilder = BeanDefinitionBuilder.rootBeanDefinition(BasicDataSource.class).addPropertyValue("url", "jdbc..");
            beanFactory.registerBeanDefinition(datasourceDefinitionBuilder.getBeanDefinition());
    }
}

@Bean(name="dataSourceMap")
public Map<String, DataSource> dataSourceMap(DataSource dataSource2011, DataSource dataSource2012) {
    // read properties from properties file and create map of datasource

    Map<DataSource> map = new HashMap<>();
    map.put("dataSource2011",dataSource2011);
    map.put("dataSource2012",dataSource2012);
    //map.put("dataSource2013",dataSource2013);
    return map;
}

@Bean(name="dataSource2011",destroyMethod="close")
public DataSource dataSource() {
    // read properties from properties file and create map of

    BasicDataSource dataSource = new BasicDataSource();
    dataSource.setDriverClassName(driverClassName);
    dataSource.setUrl(url2011);
    dataSource.setUsername(username2011);
    dataSource.setPassword(password2011);
    return dataSource;
}

@Bean(name="dataSource2012",destroyMethod="close")
public DataSource dataSource() {
    // read properties from properties file and create map of

    BasicDataSource dataSource = new BasicDataSource();
    dataSource.setDriverClassName(driverClassName);
    dataSource.setUrl(url2012);
    dataSource.setUsername(username2012);
    dataSource.setPassword(password2012);
    return dataSource;
}

<bean id="dataSource" class="someProject.DbConnectionRoutingDataSource">
    <property name="targetDataSources">
        <map key-type="int">
            <entry key="0" value-ref="placeholderDs" />
        </map>
    </property>
    <property name="defaultTargetDataSource" ref="placeholderDs" />
</bean>

@Component
class DatasourceRegisteringBeanFactoryPostProcessor implements BeanFactoryPostProcessor {
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {

        // example data, will be read from the legacy configuration
        HashMap<Integer, String> connectionsList = new HashMap<>();
        connectionsList.put(2011, "jdbc:sqlserver://localhost;databaseName=DbName_v570_2011");
        connectionsList.put(2012, "jdbc:sqlserver://localhost;databaseName=DbName_v570_2012");
        int endYear = 0;

        BeanDefinitionRegistry factory = (BeanDefinitionRegistry) beanFactory;
        BeanDefinitionBuilder datasourceDefinitionBuilder;

        // Create new beans
        for (Entry<Integer, String> e : connectionsList.entrySet()) {
            datasourceDefinitionBuilder = BeanDefinitionBuilder.childBeanDefinition("parentDataSource")
                    .addPropertyValue("url", e.getValue());

            factory.registerBeanDefinition(String.format("Year%sDataSource", e.getKey()),
                    datasourceDefinitionBuilder.getBeanDefinition());

            endYear = e.getKey();
        }

        if (endYear == 0)
            return;

        // Configure the dataSource bean properties
        MutablePropertyValues mpv = factory.getBeanDefinition("dataSource").getPropertyValues();

        // Set the default dataSource
        mpv.removePropertyValue("defaultTargetDataSource");
        mpv.addPropertyValue("defaultTargetDataSource", new RuntimeBeanReference(String.format("Year%sDataSource", endYear)));

        // Set the targetDataSource properties map
        ManagedMap<Integer, RuntimeBeanReference> mm = (ManagedMap<Integer, RuntimeBeanReference>) mpv
                .getPropertyValue("targetDataSources").getValue();
        mm.clear(); // clear the placeholder entry
        // Fill the map with bean references to the newly created beans
        for (Entry<Integer, String> e : connectionsList.entrySet()) {
            mm.put(e.getKey(), new RuntimeBeanReference(String.format("Godina%sDataSource", e.getKey())));
        }
    }
}