#Value returning null - spring

Question

I have a couple #Value annotations within my Entity Class. I am not sure why but they are both returning null. I also have "ShaPasswordEncoder" Object Autowired, which too is throwing a NullPointer Exception. I have no idea why. Please advise.
#Repository
#Configurable
#Entity
#Table(name="user")
#NamedQueries({...})
public class User implements Serializable{
#Transient private static final Logger logger = Logger.getLogger(User.class);
#Transient private static final AppUtil appUtil = new AppUtil();
#Transient #Value("some value") private String extDir;
#Transient #Value("100x100") private String imageSize;
#Transient private static byte[] salt = "FBar".getBytes();
#Transient #Autowired private ShaPasswordEncoder passwordEncoder;
....
//Default Constructor
public User(){
logger.info("TEST IMAGE => "+imageSize);
}
public String passwordEncoder(String password) {
return passwordEncoder.encodePassword(password,salt);
}

Answer 1

Making a JPA entity as a Spring bean is a bad design.
You should keep your entity simple: only getters and setters.
// Only JPA annotations
#Entity
#Table(name="user")
#NamedQueries({...})
public class User {
// Getters & Setters
}
Then you should delegate the business logic to service classes:
#Service
public class UserService {
#Autowired
private ShaPasswordEncoder passwordEncoder;
#Value("${conf.extDir}")
private String dir;
// Some operations ...
public void createUser(User user) {
// ...
}
public void updateUser(User user) {
// ...
}
}

Answer 2

Are you passing valid value expressions? For properties placeholder you can use something like:
#Value("${directory.extDirectory}")
You can also use Spring EL and get all the goodness from it using the #{value} check the docs here
Is also possible to assign a default value in case the property is not found
#Value("${directory.extDirectory:defaultValue}")

Answer 3

Using Spring annotations on a POJO means you are delegating the creation and the configuration of this bean to the Spring IoC Container !!!
The Spring container will supply all the required dependencies.
For example:
#Component
public class MyBean {
#Value("${data}")
private String data;
#Autowired
private MyService service;
// ...
}
When you try to instantiate a bean using the new operator, you will get null values.
MyBean bean = new MyBean();
In order to have a fully-configured bean you MUST get it from the applicationContext. The Spring container will provide all the requested dependencies.
MyBean bean = (MyBean) applicationContext.getBean(MyBean.class);
Or
#Component
public class AnotherBean {
// You are sure that Spring will create and inject the bean for you.
#Autowired
private MyBean bean;
}

Answer 4

Although the bean is managed by Spring it is also possible that you make a new bean yourself instead of getting it from spring container.
So below code will make a new user but it is not get from Spring context.
User user = new User()
If you use above code the #value is not applied to your bean.
If you want you must get the User from Spring by #Autowired
public class SampleService{
#Autowired
private User user;
public void Sample(){
user.getExtDir(); //here user.extDir is not null
}
}