CORS preventing access and data retrieval

I'm trying to setup a new project based on a working existing project. I haven't been able to get the database connection to work through JDBC. I'm not getting any errors, just an empty list result. I know there is something wonky with the setup of the database, because I was getting an error that the bean for the NamedParameterJdbcTemplate was not found. In the previous project, I had defined the database connection information in the application-default.properties, which was sufficient to allow spring to pick it up and use. However, to resolve the issue, I added a bean to the WebSecurity/Configuration file. This resolved that issue, allowing the database to at least connect. I know the connection is working, because if I intentionally mistype a table/column name then I get a SQL error that it can't find the table. Since it is finding the table, I can't fathom at this point what is preventing data from coming back.

I'll note that I know there are misconfigurations I have to figure out somewhere. Not only can I not define the database in the application.properties, but I also can't get cors to work either, and have been allowing all traffic for now because I've spent ages on trying to figure out cors and gotten nowhere.

Code:

Repository:

@Slf4j
@Repository
public class TestRepository {
    private final String FIND_ALL_QUERY = 
            "SELECT " + 
            "   test.ids AS id, " + 
            "   test.value AS value " + 
            "FROM test_table test ";

    @Autowired
    private NamedParameterJdbcTemplate namedParameterJdbcTemplate;
    
    @Autowired
    private DataSource dataSource;
    
    @Transactional
    public List<TestDto> findAll() {
        log.info("running query...");
        return this.namedParameterJdbcTemplate.query(FIND_ALL_QUERY, BeanPropertyRowMapper.newInstance(TestDto.class));
    }
}

Web Security:

@Slf4j
@PropertySource("classpath:application.properties")
@Configuration
@EnableWebSecurity
public class SecurityConfig {   
    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        log.info("In securityFilterChain"); 
        
        http.csrf().disable().authorizeHttpRequests().anyRequest().permitAll();
        
        return http.build();
    }

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource ds = new DriverManagerDataSource();
        ds.setDriverClassName("oracle.jdbc.OracleDriver");
        ds.setUrl("jdbc:oracle:thin:@localhost:1521");
        ds.setUsername("c##redacted");
        ds.setPassword("redacted");
        return ds;
    }
    
    @Bean
    public NamedParameterJdbcTemplate namedParameterJdbcTemplate() {
        return new NamedParameterJdbcTemplate(dataSource());
    }
}

application.properties:

spring.datasource.url=jdbc:oracle:thin:@localhost:1521
spring.datasource.username=c##redacted
spring.datasource.password=redacted
spring.datasource.driver-class-name=oracle.jdbc.OracleDriver

spring.datasource.hikari.maxLifetime=60000

Service Implementation:

@Slf4j
@RequiredArgsConstructor
@Service
public class TestServiceImpl implements TestService {
    @Autowired
    private TestRepository testRepository;

    public List<TestDto> findAll() {
        List<TestDto> test = testRepository.findAll();
        log.info("test.size(): ", test.size());
        log.info("test.get(0): ", test.get(0));
        return test;
    }
}

Database Table:

Output:

2025-05-24 13:16:05 INFO  campaign.controller.TestController - findingAll...
2025-05-24 13:16:05 INFO  campaign.repository.TestRepository - running query...
2025-05-24 13:16:05 INFO  c.serviceimpl.TestServiceImpl - test.size():
2025-05-24 13:16:05 INFO  c.serviceimpl.TestServiceImpl - test.get(0):

Edit: This may still be an issue with CORS. I don't know how given the reconfiguration I did to WebSecurity to remove everything related to authentication and cors. However, I'm getting this error in the web console:

Access to XMLHttpRequest at 'http://127.0.0.1:8080/archlands/api/test/value' from origin 'http://localhost:4200' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

TestDto (shared by request from comment):

@Data
@ToString
@RequiredArgsConstructor
@AllArgsConstructor
@Entity
public class TestDto {
    private Long id;
    private String value;
    
    @Override
    public boolean equals(Object checkObject) {
        Boolean usersAreEqual = false;
        if (this == checkObject) {
            usersAreEqual = true;
        } else if (checkObject == null || Hibernate.getClass(this) != Hibernate.getClass(checkObject)) {
            usersAreEqual = false;
        } else { // correct type, check values
            TestDto checkUser = (TestDto) checkObject;
            if (id != null) {
                usersAreEqual = Objects.equals(id, checkUser.id);
            }
        }
        return usersAreEqual;
    }

    @Override
    public int hashCode() {
        return getClass().hashCode();
    }
}

Fix CORS Policy Error as below

You mentioned:

"No 'Access-Control-Allow-Origin' header is present..."

Fix CORS in Spring Boot

Update your SecurityConfig to explicitly enable CORS:

@Configuration
@EnableWebSecurity
public class SecurityConfig {

    @Bean
    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
        http
            .cors(Customizer.withDefaults()) // Enable CORS
            .csrf().disable()
            .authorizeHttpRequests()
            .anyRequest().permitAll();
        return http.build();
    }

    @Bean
    public CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowedOrigins(List.of("http://localhost:4200")); // Your frontend
        config.setAllowedMethods(List.of("GET", "POST", "PUT", "DELETE", "OPTIONS"));
        config.setAllowedHeaders(List.of("*"));
        config.setAllowCredentials(true);

        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", config);
        return source;
    }
}

Other Problem : @RequiredArgsConstructor with fields not final

Your fields id and value are not final, but you have, Remove @RequiredArgsConstructor annotation.

This has no effect unless fields are final or annotated with @NonNull.