CODEWITHSUNDEEP
springinversion-of-control
dzrkot
dzrkot

Reputation: 603

don't understand ioc java behavior

I try use IoC without xml. But I don't understand why @Autowired workin in the first case, and doesn't work in second case: I have 3 classes:

@Configuration 
public class DataSourceBean{
    @Bean
    public DataSource dataSource(){
        DataSource ds = new DataSource();
        ds.setDriverClassName("com.mysql.jdbc.Driver");
        ds.setUrl("jdbc:mysql://192.168.1.99:3306/somethink");
        ds.setUsername("devusr");
        ds.setPassword("root");
        ds.setInitialSize(5);
        ds.setMaxActive(10);
        ds.setMaxIdle(5);
        ds.setMinIdle(2);
        return ds;
    }
}


public class AbstractDao {
@Autowired
private DataSource dataSource;

    @Autowired
    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    public AbstractDao(){
        System.out.println("dataSource = " + dataSource);
    }
}

and

@RestController
public class PageController {
    @Autowired
    private DataSource dataSource;
    private AbstractDao dao;

    @RequestMapping(value = "/test" , method = RequestMethod.GET)
    public String homePage(){
//        System.out.println("$$ dataSource = " + dataSource);
        AbstractDao dao = new AbstractDao();
        return "";
    }
}

and in a PageControllers autowiring works properly, I see that it doesn't null. And when I create new AbstractDao autowired doesn't work and dataSourse == null . I try add some annotations to class AbstractDao, but it doesn't work. what am I doing wrong? and how I must do it properly? Thanks

Upvotes: 0

Views: 28

Answers (1)

Lutz Müller
Lutz Müller

Reputation: 584

In your PageController you have to inject AbstractDao. Autowiring does not work when instantiating Objects with new operator. Try this instead in your PageController:

@RestController
public class PageController {
    @Autowired
    private DataSource dataSource;
    @Autowired
    private AbstractDao dao;

    @RequestMapping(value = "/test" , method = RequestMethod.GET)
    public String homePage(){
//        System.out.println("$$ dataSource = " + dataSource);
        return "";
    }

}

Upvotes: 1

Related Questions