spring-在静态类中从Spring容器中获取Bean

在静态方法中如果想要获取spring bean容器中的实例，则此静态类需要实现ApplicationContextAware接口且需要加 @Component 注解，否则ApplicationContext无法注入。

具体代码如下：

import com.nb.demo.entity.Demo;
import com.nb.demo.service.IDemoService;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
import java.util.Objects;
@Component
public class util implements ApplicationContextAware {
    private static ApplicationContext applicationContext;
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        if (Objects.isNull(util.applicationContext)) {
            util.applicationContext = applicationContext;
        }
    }
    public static void callDemoService(Demo demo) {
        // 使用applicationContext获取service实例
        IDemoService bean = util.applicationContext.getAutowireCapableBeanFactory().getBean(IDemoService.class);
        bean.save(demo);
    }
}