I would like to use @Value on a property but I always get 0(on int).
But on a constructor parameter it works.
Example:
@Component
public class FtpServer {
@Value("${ftp.port}")
private int port;
public FtpServer(@Value("${ftp.port}") int port) {
System.out.println(port); // 21, loaded from the application.properties.
System.out.println(this.port); // 0???
}
}
The object is spring managed, else the constructor parameter wouldn't work.
Does anyone know what causes this weird behaviour?
Field injection is done after objects are constructed since obviously the container cannot set a property of something which doesn't exist. The field will be always unset in the constructor.
If you want to print the injected value (or do some real initialization :)), you can use a method annotated with @PostConstruct, which will be executed after the injection process.
@Component
public class FtpServer {
@Value("${ftp.port}")
private int port;
@PostConstruct
public void init() {
System.out.println(this.port);
}
}