SpringMVC獲取request的方式有哪些？小編來告訴大家。

1.最簡單的方式(注解法)

@Autowired
private  HttpServletRequest request;

2.最麻煩的方法

(1)在web.xml中配置一個(gè)監(jiān)聽

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

(2)之后在程序里可以用

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

原理

RequestContextListener實(shí)現(xiàn)了 ServletRequestListener ,在其覆蓋的requestInitialized(ServletRequestEvent requestEvent)方法中,將request最終設(shè)置到了RequestContextHolder中.

public class RequestContextListener implements ServletRequestListener {
    private static final String REQUEST_ATTRIBUTES_ATTRIBUTE =
            RequestContextListener.class.getName() + ".REQUEST_ATTRIBUTES";
    @Override
    public void requestInitialized(ServletRequestEvent requestEvent) {
        if (!(requestEvent.getServletRequest() instanceof HttpServletRequest)) {
            throw new IllegalArgumentException(
                    "Request is not an HttpServletRequest: " + requestEvent.getServletRequest());
        }
        HttpServletRequest request = (HttpServletRequest) requestEvent.getServletRequest();//從事件對象中獲取request對象
        ServletRequestAttributes attributes = new ServletRequestAttributes(request);//將request設(shè)置到servletRequestAttributes中
        request.setAttribute(REQUEST_ATTRIBUTES_ATTRIBUTE, attributes);//反過來將servletRequestAttributes設(shè)置到request中
        LocaleContextHolder.setLocale(request.getLocale());
        RequestContextHolder.setRequestAttributes(attributes);//再將servletRequestAttributes設(shè)置到requestContextHolder中
    }

3.最直接的方法

public String hello(HttpServletRequest request,HttpServletResponse response) 

通過以上介紹相信大家對SpringMVC獲取request的方式已經(jīng)有所了解，大家如果想了解更多相關(guān)知識(shí)，不妨來關(guān)注一下動(dòng)力節(jié)點(diǎn)的Java在線學(xué)習(xí)，里面的課程內(nèi)容豐富，從入門到精通，很適合零基礎(chǔ)的小伙伴學(xué)習(xí)，希望對大家能夠有所幫助。