How to get a list of beans?

I have something like :

@Configuration
@EnableTransactionManagement
public class JdbcTemplateConfig{
 
   @Bean("JdbcTemplateOne")
   public NamedParameterJdbcTemplate (@Qualifier(firstDataSource final DataSource ds)){
       return new NamedParameterJdbcTemplate(ds); 
   }

   @Bean("JdbcTemplateTwo")
   public NamedParameterJdbcTemplate (@Qualifier(secondDataSource final DataSource ds)){
       return new NamedParameterJdbcTemplate(ds); 
   }

   @Bean("JdbcTemplateThree")
   public NamedParameterJdbcTemplate (@Qualifier(thirdDataSource final DataSource ds)){
       return new NamedParameterJdbcTemplate(ds); 
   }
}

and now I need a list of above templates. To get a one by one (for example in an IT-Test) I can make something like:

 @SpringBootTest
 public class SomeITCase{

      @Autowired
      @Qualifier("JdbcTemplateOne")
      private NamedParameterJdbcTemplate jdbcTemplate1;

      @Autowired
      @Qualifier("JdbcTemplateTwo")
      private NamedParameterJdbcTemplate jdbcTemplate2;

      @Autowired
      @Qualifier("JdbcTemplateThree")
      private NamedParameterJdbcTemplate jdbcTemplate3;

      ???
      List<NamedParameterJdbcTemplate> myList = ???
}

Question: How to get all templates in a list without to have declaring them one by one?

To get list of all the beans from the Application context, you can do:

public void beanNames(ApplicationContext ctx) {
      String[] beanNames = ctx.getBeanDefinitionNames();
      for (String beanName : beanNames) {
        System.out.println(beanName);
      }
}

You can also look into Spring boot acutator. It provides endpoints like /bean to get all the beans registered with Spring.

What you a re looking for is a straight forward @Autowired annotation.

Let's suppose we have several beans defined like in your above example.

Now, we create a test like below:

@SpringBootTest
@Slf4j
public class SomeITCase {
        
    @Autowired
    @Qualifier("JdbcTemplateTwo")
    private NamedParameterJdbcTemplate jdbcTemplate2;

    @Autowired
    List<NamedParameterJdbcTemplate> allTemplates;

    @Test
    public void testMyList() {
        assertThat(allTemplates)
                .hasSize(3)
                .contains(jdbcTemplate2);
    
        allTemplates.forEach(template -> {
            log.info(template.toString());
        });
    }
}

Executing this test should make it really obvious: Spring injects all beans of matching type in your list. The test ensures that the size is three and at least the one known bean reference is contained.

For further information on getting started with @Autowired, maybe take a look at Injecting collections - Injecting Bean references.

If you just want a list of all NamedParameterJdbcTemplate beans in your application, you could just ask spring to autowire it for you. It allows you to autowire a list of all beans of a specific type:

{
...
      @Autowired
      private List<NamedParameterJdbcTemplate> allJdbcTemplates;
...
}