import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;

@Component
public class SpringContextUtil implements ApplicationContextAware {

    /**
     * 上下文對象實例
     */
    private static ApplicationContext applicationContext;

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

    /**
     * 獲取applicationContext
     *
     * @return
     */
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    /**
     * 獲取HttpServletRequest
     */
    public static HttpServletRequest getHttpServletRequest() {
        return ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
    }

    public static String getDomain(){
        HttpServletRequest request = getHttpServletRequest();
        StringBuffer url = request.getRequestURL();
        return url.delete(url.length() - request.getRequestURI().length(), url.length()).toString();
    }

    public static String getOrigin(){
        HttpServletRequest request = getHttpServletRequest();
        return request.getHeader("Origin");
    }

    /**
     * 通過name獲取 Bean.
     *
     * @param name
     * @return
     */
    public static Object getBean(String name) {
        return getApplicationContext().getBean(name);
    }

    /**
     * 通過class獲取Bean.
     *
     * @param clazz
     * @param       <T>
     * @return
     */
    public static <T> T getBean(Class<T> clazz) {
        return getApplicationContext().getBean(clazz);
    }

    /**
     * 通過name,以及Clazz返回指定的Bean
     *
     * @param name
     * @param clazz
     * @param       <T>
     * @return
     */
    public static <T> T getBean(String name, Class<T> clazz) {
        return getApplicationContext().getBean(name, clazz);
    }
}

/**
 * @Project:
 * @Description:
 * @Auther: songwp
 * @Date: 2022/1/30 10:23
 **/
@Mapper
public interface EmployeeMapper {

    List<Employee> findAll();

    Employee selectById(Integer id);
}

   @Test
   public void contextLoads(){
        EmployeeMapper empService = SpringContextUtil.getBean(EmployeeMapper.class);
        System.out.println(empService.findAll());

    }