SpringBoot 中普通如何调用 Service 或 Dao 层

1. 首先新建一个通过上下文获取 bean 的工具类

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);
    }
}

2. 在启动主类中引入这个工具类

//让自定义的工具类自动导入
@Import(SpringUtil.class)
@SpringBootApplication
public class TestApplication {

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

}

3.在普通类中调用 service 层方法

// 获取 service 层的类
ApplicationContext applicationContext = SpringUtil.getApplicationContext();
TestService testService = applicationContext.getBean(TestService.class);