Spring中获取上下文的几种方式

• 通过加载配置文件方式获取

//不是根目录下
ApplicationContext context = new FileSystemXmlApplicationContext("WebContent/WEB-INF/config/base/applicationContext.xml");
//根目录下
ApplicationContext context1 = new ClassPathXmlApplicationContext("applicationContext.xml");

 

• 通过 WebApplicationContextUtils 的 getWebApplicationContext(servletContext) 获取，

使用该方法的必须依赖Servlet容器。

    public JsonResult edit(SysRoleEntity entity, HttpServletRequest request){
        ServletContext servletContext = request.getSession().getServletContext();
        ApplicationContext context =         WebApplicationContextUtils.getWebApplicationContext(servletContext);
        SysRoleService bean = context.getBean(SysRoleService.class);
        boolean modify = sysRoleService.modify(entity);
        return new JsonResult().ok(modify);
    }

 

• 通过实现 ApplicationContextAware 接口的方式

@Component
public class SpringUtil implements ApplicationContextAware {

    private static ApplicationContext context;


    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        if (SpringUtil.context == null){
            SpringUtil.context = applicationContext;
        }
    }

    /**
     * 获取ApplicationContext
     * @return
     */
    public static ApplicationContext getContext() {
        return context;
    }

    public static Object getBean(String name){
        return getContext().getBean(name);
    }

    public static <T> T getBean(Class<T> clazz){
        return getContext().getBean(clazz);
    }

}

重写 setApplicationContext(ApplicationContext applicationContext) 在 String 启动的时候 Spring 会帮我们装载

需要注意的是要把 SpringUtil 交给 Spring 管理 加个 @Component 注解 或者配置