使tomcat7支持put 、delete请求

<servlet>
        <servlet-name>default</servlet-name>
        <servlet-class>org.apache.catalina.servlets.DefaultServlet</servlet-class>
		<init-param>
            <param-name>debug</param-name>
            <param-value>0</param-value>
        </init-param>
        <init-param>
            <param-name>listings</param-name>
            <param-value>false</param-value>
        </init-param>
		<init-param>     
			<param-name>readonly</param-name>    
			<param-value>false</param-value>  
		</init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>


<security-constraint>
			<web-resource-collection>
				<url-pattern>/*</url-pattern>
				<!--
				<http-method>PUT</http-method>
				<http-method>DELETE</http-method>
				-->
				<http-method>HEAD</http-method>
				<http-method>OPTIONS</http-method>
				<http-method>TRACE</http-method>
			</web-resource-collection>
			<auth-constraint></auth-constraint>
		</security-constraint>