CODEWITHSUNDEEP
javaspring-boot
JayC
JayC

Reputation: 2292

How to load @Value annotation in the main class?

@SpringBootApplication
public class App {

    @Value("${Application}")
    private String application;
    @Value("${APP_SERVER_CPU_ENABLED}")
    private String APP_SERVER_CPU_ENABLED;
    @Value("${APP_SERVER_MEMORY_ENABLED}")
    private String APP_SERVER_MEMORY_ENABLED;

    @Autowired
    MonitoringItems mI;

    public static void main(String[] args) {
    SpringApplication.run(App.class, args);
    MonitoringItems mI=null;                    

    try {
        System.out.println(APP_SERVER_CPU_ENABLED);
        System.out.println(APP_SERVER_MEMORY_ENABLED);

if (APP_SERVER_MEMORY_ENABLED.equalsIgnoreCase("true") && APP_SERVER_CPU_ENABLED.equalsIgnoreCase("true")) {
  //do something 
  }

How come the main class cannot read the @Value annotations? In my other classes I have to put @Configuration, @ComponentScan, @EnableAutoConfiguration above the class and then @PostConstruct above the constructor. And I was able to retrieve the values from the application.properties. How would I be able to do that for the main class?

Upvotes: 0

Views: 6668

Answers (2)

Abdelmjid EL KIHEL
Abdelmjid EL KIHEL

Reputation: 126

So after 3 years i show you an astuce to do that.

  @SpringBootApplication
public class Demo1Application {

    public static void main(String[] args) {
        ApplicationContext context = SpringApplication.run(Demo1Application .class, args);
        Test test = context.getBean(Test.class);

        String password = test.getPassword();

        System.out.println(password);

    }

    @Component
    class Test {

        @Value("${password}")
        private String password;

        public String getPassword() {
            return password;
        }
    }
}

of course you create your property in a file properties like application.properties for example :

password = sxqdqdqdqdqdqd

Upvotes: 2

Roel Strolenberg
Roel Strolenberg

Reputation: 2950

The problem is that you cannot make your @Values static, because Spring may not have initialized them yet. You can however get the value you want BEFORE spring is initialized by retrieving them from the system/environment variables instead of via a properties file.

String value = System.getProperty("SOME_KEY");

Upvotes: 1

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