SpringBoot 获取 Bean 的优雅方式 - SpringContextUtil 类封装

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

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

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

    '/**
     * 获取 ApplicationContext
     */'
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    '/**
     * 根据 beanName 获取 Bean
     */'
    public static Object getBean(String beanName) {
        return applicationContext.getBean(beanName);
    }

    '/**
     * 根据 class 获取 Bean
     */'
    public static <T> T getBean(Class<T> clazz) {
        return applicationContext.getBean(clazz);
    }

    '/**
     * 根据 beanName 和 class 获取 Bean
     */'
    public static <T> T getBean(String beanName, Class<T> clazz) {
        return applicationContext.getBean(beanName, clazz);
    }
}

使用方法：

@Service
public class UserServiceImpl implements UserService {

    @Override
    public User getUserById(Long userId) {
        UserDao userDao = SpringContextUtil.getBean(UserDao.class);
        return userDao.getUserById(userId);
    }
}