SpringBoot调用service层的三种方法

public interface MyService {  
    String doSomething();  
}

@Service  
public class MyServiceImpl implements MyService {  
    @Override  
    public String doSomething() {  
        return "Something done!";  
    }  
}

@RestController  
@RequestMapping("/api")  
public class MyController {  
 
    private final MyService myService;  
 
    @Autowired  
    public MyController(MyService myService) {  
        this.myService = myService;  
    }  
 
    @GetMapping("/dosomething")  
    public ResponseEntity<String> doSomething() {  
        String result = myService.doSomething();  
        return ResponseEntity.ok(result);  
    }  
}

@Component  
public class AnotherComponent {  
 
    private final MyService myService;  
 
    @Autowired  
    public AnotherComponent(MyService myService) {  
        this.myService = myService;  
    }  
 
    public void someMethod() {  
        String result = myService.doSomething();  
        // Do something with the result  
    }  
}

package com.example.iotdemo.util;
 
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
 
@Component
public class SpringUtil implements ApplicationContextAware {
    private static ApplicationContext applicationContext = null;
 
 
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        if(SpringUtil.applicationContext == null){
            SpringUtil.applicationContext  = applicationContext;
        }
 
    }
 
    //获取applicationContext
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }
 
    //通过name获取 Bean.
    public static Object getBean(String name){
        return getApplicationContext().getBean(name);
 
    }
 
    //通过class获取Bean.
    public static <T> T getBean(Class<T> clazz){
        return getApplicationContext().getBean(clazz);
    }
 
    //通过name,以及Clazz返回指定的Bean
    public static <T> T getBean(String name,Class<T> clazz){
        return getApplicationContext().getBean(name, clazz);
    }
}
 

    //注入service
    private static MyService myService;
 
    public static void main(String[] args) throws InterruptedException {
        SpringApplication.run(TestApplication.class, args);
        ApplicationContext context = SpringUtil.getApplicationContext();
        myService= context.getBean(MyService.class);
        //调用service方法
        myService.someMethod();            
    }