invoke a method in Liferay - liferay

Question

I use Liferay Tomcat bundle 6.2, and I work with Liferay IDE(eclipse)
How I can invoke a method in Liferay?
I create one Liferay Plugin Project and write in java class this following code. But I don't know, How I can invoke this method?
I can't create a main class in Liferay. But, I think, I can invoke this method in view.jsp with creating an action URL, it this right?
Can you give me a sample example?
Thank you
public class TestLoggerPortlet extends MVCPortlet {
private static final Log logger = LogFactoryUtil.getLog(TestLoggerPortlet.class);
public void addEntry() {
logger.info("This is my message.");
if (logger.isDebugEnabled()) logger.debug("Not always printed.");
}
}

Answer 1

I think you are confusing desktop/mobile application with web application.
In my mind you have to study Java EE basics (how a browser performs a request to an application server and, how to server proceed to understand the request and dispatch it to the right method of the righte class, etc... it is called "servlet lifecycle").
Then should be easy to understand the differences with a portlet lifeycle (and how Liferay MVC portlets work for managing what you need).
I can suggest some interesting reading (in order of learning path):
http://docs.oracle.com/javaee/6/tutorial/doc/bnafd.html (see lifecycle part); basics to have a global idea about what happens behind the stages;
http://www.opensource-techblog.com/2014/12/introduction-to-portlet-phases-and.html an easy comparation to portlet lifecycle;
https://www.liferay.com/it/documentation/liferay-portal/6.0/development/-/ai/portlet-development - Liferay official general introduction to development
https://dev.liferay.com/develop/tutorials/-/knowledge_base/6-2/creating-a-liferay-mvc-portlet-project - THE TUTORIAL YOU NEED to understand how to create a simple LR mvc portlet;
https://www.liferay.com/it/web/meera.success/blog/-/blogs/liferay-mvc-portlet-development-introduction another interesting tutorial.
Hope it helps

Answer 2

See the below code.
view.jsp
<portlet:defineObjects />
<portlet:actionURL var="myAction" name="myAction">
<portlet:param name="someTxt" value="Text Message" />
</portlet:actionURL>
<form action="<%= myAction %> method="post" name="fm">
<input name="<portlet:namespace/>txtName" type="text" />
<input type="submit" name="<portlet:namespace/>submit" value="submit"/> 
</form>
Controller Class. TestLoggerPortlet.java
package com.test;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.PortletException;
import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.upload.UploadPortletRequest;
import com.liferay.portal.kernel.util.FileUtil;
import com.liferay.portal.model.User;
import com.liferay.portal.service.UserServiceUtil;
import com.liferay.portal.util.PortalUtil;
import com.liferay.util.bridges.mvc.MVCPortlet;
/**
* Portlet implementation class TestLoggerPortlet
*/
public class TestLoggerPortlet extends MVCPortlet {
private static Log _log = LogFactoryUtil.getLog(TestLoggerPortlet.class);
#ProcessAction
public void myAction(ActionRequest actionRequest,
ActionResponse actionResponse) throws IOException, PortletException {
String var1 = actionRequest.getAttribute("someText");//output -> "Text Message"
String var2 = actionRequest.getAttribute("txtName");//output -> Value of Text field.
sendRedirect(actionRequest, actionResponse);
}
}