Three Methods to Obtain Spring Beans in Static Context: @PostConstruct, ApplicationContext, and ApplicationContextAware

In Spring Boot applications, static methods cannot directly access beans managed by the container. The article presents three viable approaches to bridge this gap.

Method 1: Using @PostConstruct Annotation

A component class injects the required service via @Autowired, then assigns it to a static field inside a method annotated with @PostConstruct, ensuring the assignment occurs after dependency injection.

import com.example.javautilsproject.service.AutoMethodDemoService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;

/**
 * springboot static method bean retrieval (1)
 */
@Component
public class StaticMethodGetBean_1 {
    @Autowired
    private AutoMethodDemoService autoMethodDemoService;

    @Autowired
    private static AutoMethodDemoService staticAutoMethodDemoService;

    @PostConstruct
    public void init() {
        staticAutoMethodDemoService = autoMethodDemoService;
    }

    public static String getAuthorizer() {
        return staticAutoMethodDemoService.test();
    }
}

The @PostConstruct method must have no parameters, return void, and cannot be static; it runs after all injections are completed.

Method 2: Defining a Static ApplicationContext in the Startup Class

The main Spring Boot class declares a static ConfigurableApplicationContext field and assigns the context returned by SpringApplication.run . Beans can then be fetched via ac.getBean(...) .

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class Application {
    public static ConfigurableApplicationContext ac;

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

@RestController
public class TestController {
    @GetMapping("test2")
    public void method_2() {
        AutoMethodDemoService service = Application.ac.getBean(AutoMethodDemoService.class);
        System.out.println(service.test2());
    }
}

Method 3: Manually Injecting ApplicationContext via ApplicationContextAware

A component implements ApplicationContextAware to capture the context in a static field, providing a generic getBean(Class ) method for later static access.

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class StaticMethodGetBean_3
implements ApplicationContextAware {
    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        StaticMethodGetBean_3.applicationContext = applicationContext;
    }

    public static
T getBean(Class
clazz) {
        return applicationContext != null ? applicationContext.getBean(clazz) : null;
    }
}

@Test
public void method_3() {
    AutoMethodDemoService service = StaticMethodGetBean_3.getBean(AutoMethodDemoService.class);
    System.out.println(service.test3());
}

All three approaches have been tested and work reliably for accessing beans in static contexts.