It must be some miss-configuration:) Let me repeat the steps here.
After installing Liferay 6.1 CE GA1 try if JSONWS api is visible, by accessing following urls: http://localhost:8080/api/jsonws
and (for example): http://localhost:8080/knowledge-base-portlet/api/jsonws
Now, create your portlet using latest Liferay SDK. Create at least one service method in *ServiceImpl. Run service builder
Add the following code in portlets web.xml
:
<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>
<servlet-mapping>
<servlet-name>JSON Web Service Servlet</servlet-name>
<url-pattern>/api/secure/jsonws/*</url-pattern>
</servlet-mapping>
Build war and finally deploy portlet to Liferay. After few moments, portlet will be deployed and available. JSONWS will scan your classes and find all service methods. To test if everything went ok, visit: http://localhost:8080/*portlet-context*/api/jsonws
That's all:)