1.通过注解获取(很简单,推荐):

public class Hello {
@Autowired
HttpServletRequest request; //这里可以获取到request
}

2.在web.xml中配置一个监听:

<listener>  
<listener-class>
org.springframework.web.context.request.RequestContextListener
</listener-class>
</listener>

java代码:

HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();

直接在参数中传递(此方法不好用,不建议使用):

public String hello(HttpServletRequest request)

4.如果有Struts:

HttpServletRequest request = ServletActionContext.getRequest();