如何自动连接实现接口

Question

I have been Googling the answer for a long time, but I am certain I am missing something that would bring this all together. I am just not sure what. It is failing on running the Spring server with error:

    org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'testController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.test.abc.sv.dao.TestDAO com.test.abc.sv.controller.TestController.testDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.test.abc.sv.dao.TestDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:293)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1186)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:706)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:109)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
    at com.test.abc.sv.SpringLaunch.main(SpringLaunch.java:26)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.test.abc.sv.dao.TestDAO com.test.abc.sv.controller.TestController.testDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.test.abc.sv.dao.TestDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:509)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:290)
    ... 16 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.test.abc.sv.dao.TestDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1118)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:967)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:862)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:481)
    ... 18 common frames omitted

Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'testController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.test.abc.sv.dao.TestDAO com.test.abc.sv.controller.TestController.testDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.test.abc.sv.dao.TestDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:293)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1186)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:537)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:475)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:302)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:298)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:706)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:762)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:482)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:109)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:691)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
    at com.test.abc.sv.SpringLaunch.main(SpringLaunch.java:26)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.test.abc.sv.dao.TestDAO com.test.abc.sv.controller.TestController.testDao; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.test.abc.sv.dao.TestDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:509)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:290)
    ... 16 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.test.abc.sv.dao.TestDAO] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1118)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:967)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:862)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:481)
    ... 18 more

So I am running the application from SpringLaunch.class - com.test.abc.sv

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class SpringLaunch extends SpringBootServletInitializer{

public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}

@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
    return application.sources(applicationClass);
}

private static Class<SpringLaunch> applicationClass = SpringLaunch.class;

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName("oracle.jdbc.driver.OracleDriver");
        dataSource.setUrl("jdbc:oracle:thin:@(DESCRIPTION ="
                                            +"(LOAD_BALANCE=on)"
                                            +"(FAILOVER=on)"
                                            +"(ADDRESS=(PROTOCOL=tcp)(HOST=56.276.152.217)(PORT=1521))"
                                            +"(ADDRESS=(PROTOCOL=tcp)(HOST=56.276.152.218)(PORT=1521))"
                                            +"(CONNECT_DATA=(SERVICE_NAME=test.abc.com)))");
        dataSource.setUsername("DevUser");
        dataSource.setPassword("Credential");

        return dataSource;
    }

    @Bean
    public TestDAO testDAO() {
        return new TestDAOImpl(dataSource());
    }

}

TestController.class - com.test.abc.sv.controller

    @RestController
@RequestMapping("/test")
public class TestController{


    @Autowired
    TestDAO testDao;

    final static Logger logger = Logger.getLogger(TestController.class);

    @RequestMapping(value="/setup", method = RequestMethod.GET)
    public Message setupTest(@RequestParam(value="id", required=true) String testNumber) {
        String testMsg = new String(); 

        try{
            testMsg = testDao.prepDatabase(testNumber);
        }
        catch(SQLException e)
        {
            //Log e.getMessage();
            logger.error(e.getMessage());
            System.out.println(e.getMessage());
            return new Message("-1");
        }

        return new Message(testMsg);
    }

    @RequestMapping(value="/teardown", method = RequestMethod.GET)
    public Message teardownTest(@RequestParam(value="id", required=true) String testNumber) {
        String testMsg = new String(); 

        try{
            testMsg = testDao.removeTestData(testNumber);
        }
        catch(SQLException e)
        {
            //Log e.getMessage();
            logger.error(e.getMessage());
            System.out.println(e.getMessage());
            return new Message("-1");
        }

        return new Message(testMsg);
    }

}

TestDAO.class - com.test.abc.sv.dao Interface

 public interface TestDAO {

    public String prepDatabase(String testNumber)
            throws SQLException;

    public String removeTestData(String testNumber)
            throws SQLException;

}

`TestDAOImpl.class - com.test.abc.sv.dao'

    @Component
public class TestDAOImpl implements TestDAO{

    private Log log = LogFactory.getLog(TestDAOImpl.class);

    private JdbcTemplate jdbcTemplate;

    public TestDAOImpl(DataSource dataSource) {
        jdbcTemplate = new JdbcTemplate(dataSource);
    }

    @Override
    public String prepDatabase(String testNumber)
            throws SQLException {

        //Impl Stuff

    }

    @Override
    public String removeTestData(String testNumber)
            throws SQLException {

        //Impl Stuff
    } 

}

Answer 1

From the documentation of @ComponentScan :

If specific packages are not defined scanning will occur from the package of the class with this annotation.

Your Application class is in com.test.abc.sv.controller package according to your question. So everything in com.test.abc.sv.controller and its subppackages will be scanned, but that doesn't include your custom configuration or services because they are not in supbackages of com.test.abc.sv.controller .

So the solution would be to move the Application class to for example com.test.abc package or explicitly define the package to scan as com.test.abc for instance.

Also I'm not really sure why are you using that custom configuration class. You can configure data source using Spring Boot properties .

And as for the DAO/service bean declarations in your configuration class, that's what the @Service or @Repository annotation for service and dao respectively are for. So I would suggest getting rid of those too. If you don't you will most likely get another exception, because your beans will be registered once by the component scan and second time from your configuration class, which will result in NoUniqueBeanDefinitionException .