4_SpringMVC_@RequestMapping注解

秒速五厘米 2023-09-27 13:23 149阅读 0赞

1@RequestMapping控制请求方式

method属性可以控制请求的方式,值为RequestMethod的枚举值

@RequestMapping( value = "/***" ,method = RequestMethod.GET)

2@RequestMapping控制请求参数params和请求头headers

param:表示请求中必须包含名为param的参数

!param:表示请求中不能包含名为param的参数

param = value 表示请求中包含名为param的参数,但是值必须是value

param != value 表示请求中包含名为param的参数,但是值不能是value

\{"param1","param2=value"\},可以将对于多个参数的要求写入数组

@RequestMapping( value = "/***" ,params = {"username!=root","password"})

@RequestMapping( value = "/***",headers = {"Accept-Encoding=gzip, deflate"})

3@PathVariable注解和RESTful风格的支持

普通形式的url

\*\*\*\*\*/contextPath/aaa.do

\*\*\*\*\*/contextPath/aaa.jsp

\*\*\*\*\*/contextPath/aaa.html

\*\*\*\*\*/contextPath/css/aaa.css

\*\*\*\*\*/contextPath/js/aaa.js

\*\*\*\*\*/contextPath/aaa.do?id=10&username=root

restFul风格的url

\*\*\*\*\*/contextPath/aaa/10/root

\*\*\*\*\*/contextPath/aaa

controller 处理单元

@Controller
    public class PathController {
        @RequestMapping("/testPathVariable/{id}/{username}")
        public String testPathVariable(@PathVariable("id") Integer id, @PathVariable("username") String username){
            System.out.println("id:"+id);
            System.out.println("username:"+username);
            System.out.println("testPathVariable1");
            return "success";
        }
    }

请求测试

![1b61c093c0d91e25f4c2fc1edd31acda.png][]

Http协议中,四个表示操作方式的动词"GET POST PUT DELETE",他们对应四种基本操作,GET用来获取资源,POST用来新建资源,PUT用来更新资源,DELETE用来删除资源

简单的说,就是我们在访问资源时,可以通过这四个状态来表示对于资源的不同操作,这四个状态表现为我们请求的四种方式

/controller/1 HTTP GET :得到id为1 的资源

/controller/1 HTTP DELETE :删除id为1的资源

/controller/1 HTTP PUT :更新id为1 的资源

/controller/1 HTTP POST :增加id为1 的资源

在访问同一个url的时候,通过不同的请求方式,对应到不同的controller处理单元

1 配置hiddenHttpMethodFilter

<filter>
            <filter-name>hiddenHttpMethodFilter</filter-name>
            <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
        </filter>
        <filter-mapping>
            <filter-name>hiddenHttpMethodFilter</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>

转换原理

protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
            HttpServletRequest requestToUse = request;
            if ("POST".equals(request.getMethod()) && request.getAttribute("javax.servlet.error.exception") == null) {
                String paramValue = request.getParameter(this.methodParam);// "_method"
                if (StringUtils.hasLength(paramValue)) {
                    String method = paramValue.toUpperCase(Locale.ENGLISH);
                    if (ALLOWED_METHODS.contains(method)) {
                        requestToUse = new HiddenHttpMethodFilter.HttpMethodRequestWrapper(request, method);
                    }
                }
            }
            filterChain.doFilter((ServletRequest)requestToUse, response);
        }

![03d22a4c66fbb135d3fdc0137d6da866.png][]

2 准备Controller层代码

package com.msb.controller;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    /**
     * @Author: Ma HaiYang
     * @Description: MircoMessage:Mark_7001
     */
    @RequestMapping(value = "/myController")
    @RestController
    public class MyController {
        @RequestMapping(value = "/testRest/{id}",method = RequestMethod.PUT)
        public String testPut(@PathVariable(value = "id") Integer id){
            System.out.println("testPut, id:"+id);
            return "show";
        }
        @RequestMapping(value = "/testRest/{id}",method = RequestMethod.DELETE)
        public String testDelete(@PathVariable(value = "id") Integer id){
            System.out.println("testDelete, id:"+id);
            return "show";
        }
        @RequestMapping(value = "/testRest/{id}",method = RequestMethod.POST)
        public String testPOST(@PathVariable(value = "id") Integer id){
            System.out.println("testPOST, id:"+id);
            return "show";
        }
        @RequestMapping(value = "/testRest/{id}",method = RequestMethod.GET)
        public String testGET(@PathVariable(value = "id") Integer id){
            System.out.println("testGET, id:"+id);
            return "show";
        }
    }

3 准备页面代码

[1b61c093c0d91e25f4c2fc1edd31acda.png]: https://img-blog.csdnimg.cn/img_convert/1b61c093c0d91e25f4c2fc1edd31acda.png
[03d22a4c66fbb135d3fdc0137d6da866.png]: https://img-blog.csdnimg.cn/img_convert/03d22a4c66fbb135d3fdc0137d6da866.png