SpringBoot中Rest映射

@RequestMapping(value = "/user",method = RequestMethod.GET)
    @ResponseBody
    public String getUser(){
        return "GET-张三";
    }

    @RequestMapping(value = "/user",method = RequestMethod.POST)
    @ResponseBody
    public String saveUser(){
        return "POST-张三";
    }


    @RequestMapping(value = "/user",method = RequestMethod.PUT)
    @ResponseBody
    public String putUser(){
        return "PUT-张三";
    }

    @RequestMapping(value = "/user",method = RequestMethod.DELETE)
    @ResponseBody
    public String deleteUser(){
        return "DELETE-张三";
    }

<form action="/user" method="get">
        <input value="REST-GET 提交" type="submit"/>
    </form>
    <form action="/user" method="post">
        <input value="REST-POST 提交" type="submit"/>
    </form>
    <form action="/user" method="post">
        <input type="hidden" name = "_method" value="PUT">
        <input value="REST-PUT 提交" type="submit"/>
    </form>
    <form action="/user" method="post">
        <input type="hidden" name = "_method" value="DELETE">
        <input value="REST-DELETE 提交" type="submit"/>
    </form>

spring:
  mvc:
    hiddenmethod:
      filter:
        enabled: true

	@Bean
    @ConditionalOnMissingBean(HiddenHttpMethodFilter.class)
    @ConditionalOnProperty(prefix = "spring.mvc.hiddenmethod.filter", name = "enabled", matchIfMissing = false)
    public OrderedHiddenHttpMethodFilter hiddenHttpMethodFilter() {
        return new OrderedHiddenHttpMethodFilter();
    }


    //自定义filter
    @Bean
    public HiddenHttpMethodFilter hiddenHttpMethodFilter(){
        HiddenHttpMethodFilter methodFilter = new HiddenHttpMethodFilter();
        methodFilter.setMethodParam("_m");
        return methodFilter;
    }

Rest原理（表单提交要使用REST的时候）

表单提交会带上_method=PUT

请求过来被HiddenHttpMethodFilter拦截

请求是否正常，并且是POST

获取到_method的值。

兼容以下请求；PUT.DELETE.PATCH

原生request（post），包装模式requesWrapper重写了getMethod方法，返回的是传入的值。

过滤器链放行的时候用wrapper。以后的方法调用getMethod是调用requesWrapper的。

Rest使用客户端工具，

如PostMan直接发送Put、delete等方式请求，无需Filter。