How to create a top-level servlet in liferay

Question

I wanted to create a servlet in liferay that is listening to a URL such as

http://localhost:8080/my-servlet

I tried to add it to a portlet

Answer 1

If you want to access Liferay service API, you may consider using PortalDelegateServlet : adding the following to your web.xml:

<servlet>
    <servlet-name>myServlet</servlet-name>
    <servlet-class>com.liferay.portal.kernel.servlet.PortalDelegateServlet</servlet-class>
    <init-param>
        <param-name>servlet-class</param-name>
        <param-value>org.example.MyServlet</param-value>
    </init-param>
    <init-param>
        <param-name>sub-context</param-name>
        <param-value>myservlet</param-value>
    </init-param>
</servlet>

will make your servelt accessible through

http://example.org/delegate/myservlet

in your servlet class, you then do things like extract the logged-in user and check permissions:

package org.example;

public class MyServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    User user = PortalUtil.getUser(request);
    PermissionChecker permissionChecker = PermissionCheckerFactoryUtil.create(user);
    ...

Answer 2

Liferay is also "Servlet"-Application - but a very-very big one. And Liferay need some servlet container like tomcat, jetty, jboss etc.

However, you can simple create servlet project and deploy it direct to servlet container where liferay is running.

edit: and put to web.xml by servlet-mapping a direct access like "/*".