如果使用@Value注释从属性文件注入参数，如何调用函数

Question

I am new to spring and saw this approach for resolving method parameter from properties file...

public void setUserDetails(@Value("${user.first.name}")String userName,
  @Value("${user.address}") String address) {
    this.userName = userName;
    this.address = address;
}

but whenever i call this function the values are replaced by what i pass to function. i want to know how to call the function so that the values are fetched from properties file.

I am calling the function like...

setUserDetails("abc","xyz")
setUserDetails("abc",null)
setUserDetails(null,"xyz")
setUserDetails(null,null)  
setUserDetails(null)       // invalid
setUserDetails()      // invalid

Everytime i get what i pass not from the data from properties. Please help to find me some solution or some reference link which may be helpful...

Answer 1

As mentioned on https://stackoverflow.com/a/21769581/679240 , that annotation won't interfere on a manual invocation of the method; instead, it will automatically invoke the method right after instantiating the bean.

As the manual states:

Fields are injected right after construction of a bean, before any config methods are invoked. [...] Bean property setter methods [as in this case] are effectively just a special case of such a general config method.

Answer 2

Spring annotation works on bean creation, not during methods invocation. Suppose your class is called UserDetails :

@Component
public class UserDetails{
 public @Value("${user.first.name}") String userName;
 public @Value("${user.address}") String address;
}