package com.serverside.validation.test.controller;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.portlet.bind.annotation.ActionMapping;
import org.springframework.web.portlet.bind.annotation.RenderMapping;

import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.servlet.SessionErrors;
import com.liferay.portal.kernel.util.ParamUtil;

@Controller(value = "ServerSideValidationTestViewController")
@RequestMapping("VIEW")
public class ServerSideValidationTestViewController {
 private static Log log = LogFactoryUtil.getLog(ServerSideValidationTestViewController.class);
 /*
  * maps the incoming portlet request to this method
  * Since no request parameters are specified, therefore the default
  * render method will always be this method
  */
 @RenderMapping
 public String handleRenderRequest(RenderRequest request,RenderResponse response,Model model){
  
  return "profile";
 }
 
 @ActionMapping(params = "action=submitProfile") 
 public void submitProfileAction(ActionRequest request, ActionResponse response) {
  String name=ParamUtil.get(request, "name", "");
  String age=ParamUtil.get(request, "age", "");
  String email=ParamUtil.get(request, "email", "");
  
  if(name ==null || "".equalsIgnoreCase(name)){
   SessionErrors.add(request, "name-is-required");
  }
  if(age == null || "".equalsIgnoreCase(age)){
   SessionErrors.add(request, "age-is-required");
  }
  if(email == null || "".equalsIgnoreCase(email)){
   SessionErrors.add(request, "email-is-required");
  }
 }

}

• First we have defined log with the help of Liferay utility class LogFactoryUtil.
• Then we have defined default render method which simply return view (profile.jsp)
• Next to it, we have defined action method, which simply read the values that user entered as request parameter.
• Then we are validating for null or empty value. If the value is null or empty, we are calling SessionErrors.add(request,"name-is-required").
• This line of code will say that add the error with key "name-is-required" in SessionErrors object in request scope.
• To show the error message in jsp we are using liferay-ui tag and giving respective key and message. So if matching key is found then its message will be displayed otherwise no input. That is the reason on first time this jsp (profile.jsp) render, we are not getting any error message.
• This way we can set the error key in controller (Based on validation condition) and in JSP,if the matching key is found then respective error message will be displayed.

Now let us see the practical. Deploy the portlet and you will found the profile as per below screenshot.

We have keep the validation for null or empty string of all three (Name, Age and Email) value. So If we left blank any of these value and click on submit, then it will show error message as per below screenshot.

• First I have just click on Submit button without giving any value.
• Form has been submitted to controller's action method (submitProfileAction) without any value.
• In action method we are checking if these values are blank or null then we are adding error key into SessionErrors object.
• After Action method's execution finished, it will call default render method and from default render method, profile.jsp will be rendered.
• In jsp file we have defined tag <liferay-ui:error>  which will actually check whether the matched error key is present (which we have set in controller's action method in request scope) then it will show message (defined by message attribute of respective <liferay-ui:error> tag).

package com.serverside.validation.test.controller;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.portlet.bind.annotation.ActionMapping;
import org.springframework.web.portlet.bind.annotation.RenderMapping;

import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.servlet.SessionErrors;
import com.liferay.portal.kernel.servlet.SessionMessages;
import com.liferay.portal.kernel.util.ParamUtil;

@Controller(value = "ServerSideValidationTestViewController")
@RequestMapping("VIEW")
public class ServerSideValidationTestViewController {
 private static Log log = LogFactoryUtil.getLog(ServerSideValidationTestViewController.class);
 /*
  * maps the incoming portlet request to this method
  * Since no request parameters are specified, therefore the default
  * render method will always be this method
  */
 @RenderMapping
 public String handleRenderRequest(RenderRequest request,RenderResponse response,Model model){
  
  return "profile";
 }
 
 @ActionMapping(params = "action=submitProfile") 
 public void submitProfileAction(ActionRequest request, ActionResponse response) {
  String name=ParamUtil.get(request, "name", "");
  String age=ParamUtil.get(request, "age", "");
  String email=ParamUtil.get(request, "email", "");
  
  boolean isErrorOccured=false;
  if(name ==null || "".equalsIgnoreCase(name)){
   isErrorOccured=true;
   SessionErrors.add(request, "name-is-required");
  }
  if(age == null || "".equalsIgnoreCase(age)){
   isErrorOccured=true;
   SessionErrors.add(request, "age-is-required");
  }
  if(email == null || "".equalsIgnoreCase(email)){
   isErrorOccured=true;
   SessionErrors.add(request, "email-is-required");
  }
  
  if(isErrorOccured==false){
   SessionMessages.add(request, "profile-saved-successfully");
   response.setRenderParameter("action", "showSuccess");
  }
 }

 @RenderMapping (params="action=showSuccess")
 public String showSuccessPage(RenderRequest request,RenderResponse response,Model model){
  
  return "success";
 }
}

• We have create one boolean variable isErrorOccured and setting its value true in case if we found null or empty value (of name,age and email) in 3 if conditions block.
• At the end we are checking if the value of isErrorOccured is false (mean no error occurred and all user inputs are validated correctly) then we are setting success message key by SessionMessages.add(request,"profile-saved-successfully").
• It means we are storing success message key "profile-saved-successfully" in SessionMessages object in request scope
• Note that we are using SessionErrors to store error message and SessionMessages for success messages.
• After that we are calling response.setRenderParameter("action","showSuccess").
• By default, once action method execute, the default render method will be called. But if we want to call specific render method then we have to set action key of that render method through response.setRenderParameter method.
• We have created one render method with action key "showSuccess" just below the action method.
• To call this render method from action method, we are setting the value of render parameter action same as action key of render method ("showSuccess").
• And this render method will render success.jsp.
• This way, if any error occurs then the default render method will be called and if all user inputs are validated successfully then the second render method (with the action key "showSuccess") will be called.

<%@ taglib uri="http://liferay.com/tld/ui" prefix="liferay-ui" %>

<liferay-ui:success key="profile-saved-successfully" message="Your profile saved successfully"></liferay-ui:success>

package com.serverside.validation.test.controller;

import java.util.Random;

import javax.portlet.ActionRequest;
import javax.portlet.ActionResponse;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.portlet.bind.annotation.ActionMapping;
import org.springframework.web.portlet.bind.annotation.RenderMapping;

import com.liferay.portal.kernel.log.Log;
import com.liferay.portal.kernel.log.LogFactoryUtil;
import com.liferay.portal.kernel.servlet.SessionErrors;
import com.liferay.portal.kernel.util.ParamUtil;
import com.serverside.validation.test.exception.Exception1;
import com.serverside.validation.test.exception.Exception2;

@Controller(value = "ServerSideValidationTestViewController")
@RequestMapping("VIEW")
public class ServerSideValidationTestViewController {
 private static Log log = LogFactoryUtil.getLog(ServerSideValidationTestViewController.class);
 /*
  * maps the incoming portlet request to this method
  * Since no request parameters are specified, therefore the default
  * render method will always be this method
  */
 @RenderMapping
 public String handleRenderRequest(RenderRequest request,RenderResponse response,Model model){
  
  return "profile";
 }
 
 @ActionMapping(params = "action=submitProfile") 
 public void submitProfileAction(ActionRequest request, ActionResponse response) {
  String name=ParamUtil.get(request, "name", "");
  String age=ParamUtil.get(request, "age", "");
  String email=ParamUtil.get(request, "email", "");
  
 /* boolean isErrorOccured=false;
  if(name ==null || "".equalsIgnoreCase(name)){
   isErrorOccured=true;
   SessionErrors.add(request, "name-is-required");
  }
  if(age == null || "".equalsIgnoreCase(age)){
   isErrorOccured=true;
   SessionErrors.add(request, "age-is-required");
  }
  if(email == null || "".equalsIgnoreCase(email)){
   isErrorOccured=true;
   SessionErrors.add(request, "email-is-required");
  }
  
  if(isErrorOccured==false){
   SessionMessages.add(request, "profile-saved-successfully");
   response.setRenderParameter("action", "showSuccess");
  }*/
  
  Random randomGenerator = new Random();
  int number = randomGenerator.nextInt(10);
  try{
   if(number%2==0){
    throw new Exception1();
   }else{
    throw new Exception2();
   }
  }catch(Exception e){
   if(e instanceof Exception1){
    SessionErrors.add(request, Exception1.class.getName(), e);
   }else{
    SessionErrors.add(request, Exception2.class.getName(), e);
   }
  }
 }

 @RenderMapping (params="action=showSuccess")
 public String showSuccessPage(RenderRequest request,RenderResponse response,Model model){
  
  return "success";
 }
}

• In action method, I have commented out the validation logic and generating one random number between 0 to 10.
• Throwing the exception (either Exception1 or Exception2 ) based on the generated value is odd or even.
• In catch block, setting the error key by calling overloaded add  method. This method is taking 3 values as parameter, first is the actionRequest , second is the key (for which we are passing class name of exception) and third is the value of key as object (for which we are passing exception object).
• At the last, we are not setting any render parameter so that the default render method will be called and profile.jsp will be rendered.

<liferay-ui:error exception="<%=Exception1.class %>" message="Exception 1 have occured"></liferay-ui:error>
<liferay-ui:error exception="<%=Exception2.class %>" message="Exception 2 have occured"></liferay-ui:error>

Here instead of key,  we are passing the name of exception class (Exception1 and Exception2) in exception attribute of <liferay-ui:error> tag.

Let us see this in action. Deploy the portlet and it will show profile.jsp page. Now just click on Submit button and you will get message either for Exception1 or Exception 2 as per below screenshot.

If you keep clickin Submit button, it will show message for either Exception1 or Excepiotn 2. This behavior is random as we are checking whether the random number is odd or even.
And that all done. you may do some more testing by setting some more complex validation. Its also possible to pick the error or success message from language property file instead of hard code. 

I would recommend looking at index page 'A Complete Liferay Guide' to browse all topics about liferay.

Download Source

• We have to pass class reference in which we are defining logger in getLog method
• You can notice that, we not returning anything. I mean the return type of this method is void.
• So you may wonder, after this method get executed what is the output. And the answer is it will execute default Render method.

@RenderMapping(params = "action=renderAfterAction") 
 public String testRenderMethod(RenderRequest request, RenderResponse response){
  log.info("In renderAfterAction method");
  return "renderAfterAction";
 }

Explanation:-

• we created render method with its key action set to renderAfterAction. Also we are returning "renderAfterAction". Means it will search for renderAfterAction.jsp file under /WEB-INF/jsp folder.

Create new jsp file renderAfterAction under /WEB-INF/jsp folder and just enter one line content in it like "<h1>This is Render After Action JSP </h1>"

Next we will do modification in our action method so that it will looks like below snippet.

@ActionMapping(params = "action=actionOne") 
 public void actionOneMethod(ActionRequest request, ActionResponse response) {
  String userName=ParamUtil.get(request, "userName", "");
  log.info("userName is==>"+userName);
  response.setRenderParameter("action", "renderAfterAction");
 }

Explanation:-

• The only change we have done is added last line code response.setRenderParameter("action", "renderAfterAction");
• This will tell controller that after executing the action method, set render parameter action to "renderAfterAction".
• It means, the action method wants to execute specific render method with value of action key set to  renderAfterAction
• So after executing this action method it will execute testRenderMethod (who's value of action key is testRenderMethod)

Note:- setRenderParameter method is available only for object of type ActionResponse.

Deploy the folder and it will show defaultRender jsp. Give the name as "Nilang" and click on Submit button. You will see the render method renderAfterAction get execute as per below screen shot.

You also can notice the log to understand the flow as per below screenshot.

You can notice that after the action method get executed, control goes to renderAfterAction method.

Its done. you can try some more Actions and Render method combination to get more dipper knowledge.

I would recommend looking at index page 'A Complete Liferay Guide' to browse all topics about liferay.