hidden method filter

form 태그는 get과 post만 지원하기 때문에  form에 put, delete등을 쓰려면 

web.xml에 아래 필터 추가 

<filter>
    <filter-name>httpFilter</filter-name>
    <filter-class>
    	org.springframework.web.filter.HiddenHttpMethodFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>httpFilter</filter-name>
    <servlet-name>사용하는 servlet</servlet-name>
</filter-mapping>