Liferay plugin JSON WS configuration for 6.1.20 / 6.1.1

web.xml

    <filter>
        <filter-name>Secure JSON Web Service Servlet Filter</filter-name>
        <filter-class>com.liferay.portal.kernel.servlet.PortalClassLoaderFilter</filter-class>
        <init-param>
            <param-name>filter-class</param-name>
            <param-value>com.liferay.portal.servlet.filters.secure.SecureFilter</param-value>
        </init-param>
        <init-param>
            <param-name>basic_auth</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>portal_property_prefix</param-name>
            <param-value>jsonws.servlet.</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>Secure JSON Web Service Servlet Filter</filter-name>
        <url-pattern>/api/jsonws/*</url-pattern>
    </filter-mapping>

    <servlet>
        <servlet-name>JSON Web Service Servlet</servlet-name>
        <servlet-class>com.liferay.portal.kernel.servlet.PortalClassLoaderServlet</servlet-class>
        <init-param>
            <param-name>servlet-class</param-name>
            <param-value>com.liferay.portal.jsonwebservice.JSONWebServiceServlet</param-value>
        </init-param>
        <load-on-startup>0</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>JSON Web Service Servlet</servlet-name>
        <url-pattern>/api/jsonws/*</url-pattern>
    </servlet-mapping>

please provide description of web.xml like PortalClassLoaderFilter,SecureFilter,basic_auth,portal_property_prefix and JSONWebServiceServlet