How use @Autowired with Annotation config?

Question

i create simple spring project and i need to use annotation @Autowired but when i run project, i get exception NullPointerException.

This is my classes:

Main.java

public class Main {
    @Autowired
    private static InjectClass injectClass;

    public static void setInjectClass(InjectClass injectClass) {
        Main.injectClass = injectClass;
    }
    public static void main(String[] args) {
        injectClass.hello();    //NullPointerException
    }
}

ConfigurationBean

@Configuration
public class ConfigurationBean {
    @Bean
    public InjectClass injectClass(){
        return new InjectClass();
    }
}

InjectClass

public class InjectClass {
    public void hello(){
        System.out.println("Autowired success!");
    }
}

You don't seem to understand how Spring works. Review some tutorials. Spring isn't magic. It also doesn't work well with anything static. — Sotirios Delimanolis, Sep 14 '15 at 13:43
pls put link to tutorial when show how work from annotation config. — Bohdan Olehovich, Sep 14 '15 at 13:45
You need to create application context. Please Follow this link. http://stackoverflow.com/questions/3659720/using-spring-3-autowire-in-a-standalone-java-application — Subbu, Sep 14 '15 at 14:00
@Subbu, thank you, this is work! but how use `@Autowiring` without `ApplicationContext` this is real? — Bohdan Olehovich, Sep 14 '15 at 14:09

score 0 · Answer 1 · answered Sep 14 '15 at 13:54

0

You need to initiate application contex before using any bean. You can do it by writing following code in starting of your main method. AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext( ConfigurationBean.class);

answered Sep 14 '15 at 13:54

Kuldeep Singh

199
1
11

i need use `@Autowired` ! – Bohdan Olehovich Sep 14 '15 at 13:59
@BohdanOlehovich which is why you need an **Annotation**ConfigApplicationContext. – zapl Sep 14 '15 at 14:04
Because AnnotationConfigApplicationContext is the one who is responsible to initialize all beans defined in configuration class. If you will not create inctance of AnnotationConfigApplicationContext, no bean will be initialized and you will always get null for all beans. – Kuldeep Singh Sep 15 '15 at 04:39

How use @Autowired with Annotation config?

1 Answers1