spring -- @RequestAttribute注解

Myth丶恋晨 2021-09-14 13:56 848阅读 0赞

注解`@RequestAttribute`可以被用于访问由过滤器或拦截器创建的、预先存在的请求属性

例1：请求预先存在的属性。

先用@ModelAttribute定义预先存在的属性

@ModelAttribute
    	void beforeInvokingHandlerMethod(HttpServletRequest request) {
    		request.setAttribute("foo", "hello world");
    	}

用 @RequestAttribute  去请求数据：

@ModelAttribute
    	void beforeInvokingHandlerMethod(HttpServletRequest request) {
    		request.setAttribute("foo", "hello world");
    	}
    	
    	@RequestMapping(value="/data/custom", method=RequestMethod.GET)
    	public @ResponseBody String custom(@RequestAttribute("foo") String foo) {
    		return "Got 'foo' request attribute value '" + foo + "'";
    	}

在HTML页面中请求数据：

<div id="customArgs">
    			<h3>Custom Resolvable Web Arguments</h3>	
    			<ul>
    				<li>
    					<a id="customArg" class="textLink" href="<c:url value="/data/custom" />">Custom</a>
    				</li>
    			</ul>
    		</div>

用ajax请求数据：

$("a.textLink").click(function() {
    		var link = $(this);
    		$.ajax({
    			url: link.attr("href"),
    			dataType: "text",
    			success: function (text) {
    				alert(text)
    			}
    		})
    	})

运行结果：

![SouthEast][]  
  
例2：请求拦截器创建的属性。

创建一个拦截器类 TestFilter

@WebFilter(filterName = "myFilter",description = "测试过滤器",urlPatterns = {"/*"})
    public class TestFilter implements Filter {
        @Override
        public void init(FilterConfig filterConfig) throws ServletException {
    
        }
    
        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
              System.out.println(" 我是过滤器类 ");
              servletRequest.setAttribute("test","you got it ");
              filterChain.doFilter(servletRequest,servletResponse);
        }
    
        @Override
        public void destroy() {
    
        }
    }

请求创建的属性：

@RequestMapping(value="/data/custom", method=RequestMethod.GET)
    	public @ResponseBody String custom(@RequestAttribute("foo") String foo,
    									   @RequestAttribute("test") String test) {
    		System.out.println("Got 'foo' request attribute value '" + foo + "'------"+test);
    		return "Got 'foo' request attribute value '" + foo + "'------"+test;
    	}

运行结果：

![SouthEast 1][]

[SouthEast]: /images/20210813/8710530fc020493c8bf73efdde440efc.png
[SouthEast 1]: /images/20210813/03099283b6264d1c80ca8f23102f84e6.png