如何在另一个类中使用值注释？

Question

How can I get my value here and use it in another class? I wanted to create a class that handles all the @Value annotations then the other classes can get those values from this class. I will change from a main class to a new class once I learn how to get the values from another class

How can I get these variables

@Configuration
@ComponentScan
@EnableAutoConfiguration
public  class WebProperties {

       @Value("${Application}")
        private String app;      
        @Value("${APP_MEMORY_GREP_FOLDERS_APP}")
        private String appFolder;        
        @Value("${APP_MEMORY_GREP_FOLDERS_OPT}")
        private String optFolder;
      //getters and setters
}}

To print into the main class

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

    @Value("${Application}")
    private String app;

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @PostConstruct
    public void postConstruct() {
        System.out.print("SampleApplication started: " + app);
    }
}

Without having to call @Value all over again

Answer 1

You can create a new properties class annotated with @Configuration. There you annotate your Fields with @Value with all the properties you want. This class can be autowired in all other spring component Classes where the properties are needed.

This is the Configuration class where I map the properties of my application.properties file:

@Configuration
public class MyProperties{

    @Value("{my.property}")
    public String  myProperty;
}

It can be used as follows:

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

@Autowired
private MyProperties props;

public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}

@PostConstruct
public void postConstruct() {
    System.out.print("Print my property: " + props.myProperty);
}
}

This works for me. Hope it will help you.