don't understand ioc java behavior - spring

Question

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

Answer 1

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 "";
}
}