Including JSP page in Vm file

$theme.include($themeServletContext, "/elements.jsp")

make sure that elements.jsp page is available under root folder of theme

Adding Portlet in Control Panel

In liferay-portlet.xml .......write these two lines after <icon>/icon.png</icon> tag

       <control-panel-entry-category>configuration</control-panel-entry-category>

        <control-panel-entry-weight>1.0</control-panel-entry-weight>

 

 

Embedding Portlet in Layout

--------------------------for custom portlet--------------------

                      $processor.processPortlet("aluminilanding_WAR_ATS_Aluminiportlet")

 

--------------------------Out of Box Portlets--------------------
                      $processor.processPortlet("58")

 

-------------------------Syntax---------------------------------

                         $processor.processPortlet("Portlet ID")

Embedding Web Content into Portlet

In Jsp page

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

<liferay-ui:journal-article articleId="11550" groupId="10181"></liferay-ui:journal-article>

Embedding web content into theme

In portal-normal.vm file

#set ($articleId = '11550')

$theme.journalArticle($articleId, $themeDisplay.getSiteGroupId(), "")

Service Locator

#set ($journalArticleLocalService = $serviceLocator.findService("com.liferay.portlet.journal.service.JournalArticleLocalService"))

#set ($journalArticle = $journalArticleLocalService.getArticleByUrlTitle($group_id,"footer_webcontent"))






#set($userLocalService = $serviceLocator.findService('com.liferay.portal.service.UserLocalService'))
$user.getFirstName()



#set ($VOID = $velocityPortletPreferences.setValue('groupId', $themeDisplay.getScopeGroupId().toString()))
#set ($VOID = $velocityPortletPreferences.setValue('articleId', '11475'))
#set ($VOID = $velocityPortletPreferences.setValue('portletSetupShowBorders', 'false'))
#set ($portlet_id = '56')
#set ($my_portlet_id = "${portlet_id}_INSTANCE_75LVKxT6OlOQ")
$theme.runtime($my_portlet_id, "", $velocityPortletPreferences.toString())
#set ($VOID = $velocityPortletPreferences.reset())



#set ($articleId = '11519')
$theme.journalArticle($articleId, $themeDisplay.getSiteGroupId(), "")

Random Image Display using Web content in liferay

<script>
window.onload=function abc(){
   var description=[
                "$request.get("theme-display").path-theme-images/veteran/banner.jpg",
                "$request.get("theme-display").path-theme-images/veteran/1.jpg",
                "$request.get("theme-display").path-theme-images/veteran/2.jpg",
                "$request.get("theme-display").path-theme-images/veteran/3.jpg",
                "$request.get("theme-display").path-theme-images/veteran/4.jpg",
                "$request.get("theme-display").path-theme-images/veteran/5.jpg",
                "$request.get("theme-display").path-theme-images/veteran/6.jpg"
                ];
 var size = description.length

var x = Math.floor(size*Math.random())

var picture = $('.picture-tag');

var img = picture.next();

picture.attr('srcset',description[x]);

img.attr('src',description[x]);
}
</script>



<div class="banner_box ">
  <picture>
    <source srcset="$imageBannerSmall.getData()" media="(max-width: 766px)"                                  class="picture-tag">
         <img <img window.onload="abc()"/>
   </picture>
</div>

Liferay Custom field and Expando Tables

Creating Extra Field

If you want to add extra field in liferay default table ......
 In 6.2
Admin-------------->control panel--------->Custom Fields---------->User

select entity for ex..User

User-------->Add Custom Field -------->Enter Key &  Type and save it 




Saving The Custom field value

 
in jsp page
 <%
      User currentUser = themeDisplay.getUser();
          %>
          <div class="control-group">
            <label for="reportingManager" class="control-label">Reporting Manager</label>
            <div class="controls">
              <liferay-ui:custom-attribute-list
              className="<%= User.class.getName() %>"
              classPK="<%= currentUser != null ? currentUser.getUserId() : 0 %>"
              editable="<%= true %>" label="false"/>
            </div>
          </div>   
in controller
  ServiceContext serviceContext = ServiceContextFactory.getInstance(User.class.getName(),      actionRequest);
    user.setExpandoBridgeAttributes(serviceContext);
    UserLocalServiceUtil.addUser(user);


After creating custom field ,it is available in ExpandoTable and ExpandoColumn

After Saving You can check it in ExpandoValue Table



 

Fetching Last Primary Key From Table

1.     SELECT qualityId FROM `quality_quality`
        ORDER BY qualityId DESC
        LIMIT 1;

2.     select max(qualityId ) from quality_quality"


3. In Liferay
         
          Quality qua = new QualityImpl();
           long siz1 = 0 ;
     try{
          long qualityId = ParamUtil.getLong(renderRequest, "qualityId");
         qua = QualityLocalServiceUtil.getQuality(qualityId);
      if(qualityId > 0)
        siz1 = qua.getQualityId();
}catch(Exception e){
    int size=l.size();
    if(size == 0){
         siz1 = 1;
         //out.print(siz1);
    }else{
          siz1 = ((l.get(size-1).getQualityId())+1) ;
          //out.print(siz1);
      }
}

How to create Folder in Java

import java.io.File;
 
public class CreateFolder
{
    public static void main(String[] args)
    { 
 File file = new File("C:\\Folder");
 if (!file.exists()) {
  if (file.mkdir()) {
   System.out.println("Folder is created!");
  } else {
   System.out.println("Failed to create Folder!");
  }
 }
 
 File files = new File("C:\\Folder1\\Sub1\\Sub-Sub1");
 if (files.exists()) {
  if (files.mkdirs()) {
   System.out.println("Multiple Folders are created!");
  } else {
   System.out.println("Failed to create multiple Folders!");
  }
 }
 
    }
}

Creating File in java

import java.io.File;
import java.io.IOException;

public class WriteInFile {

public static void main(String[] args) {
// TODO Auto-generated method stub
try {
File f = new File("d:\\newfile.txt");       // path to create file

if (f.createNewFile()){
System.out.println("file created");
}else{
System.out.println("file is their");
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}

Using custom properties file in jsp and java files for dynamic work(In Liferay 6.2)

 Properties prop = new Properties();
 FileInputStream inputStream = new FileInputStream("/path of the file");
 prop.load(inputStream);


U can keep properties file location src else tomcat bundle

Embedding One portlet in Another (Liferay 6.2)

Write Below Lines in Jsp Page

<%@ taglib uri="http://liferay.com/tld/portlet" prefix="liferay-portlet" %>
 <liferay-portlet:runtime portletName="82" />


Where 82 is portlet Id 

Possible Data Types In Liferay Service Layer

• String
• Boolean
• Date
• long
• Collection
• int
• double
• Blob

How to Increase the size of Column in Liferay?

By Default Size of Column(Data type String ) is 75..

If We Want Increase this size write the sentence like below in portlet-model-hints.xml under
docroot/WEB-INF/SRC/META-INF

                 <field name="description" type="String">

<hint name="max-length">500</hint>

</field>

and build service.xml once......

Sorting Column in Search Container

• Write orderable and orderableProperty for column like below

<liferay-ui:search-container-column-text name="Start Date" property="startDate" orderable="true" orderableProperty="startDate"/>

•  Write render Method in controller class

@Override

public void render(RenderRequest request, RenderResponse response)

throws IOException, PortletException {

//System.out.println("hello1");

setSortParams(request);

super.render(request, response);

}

private void setSortParams(RenderRequest request) {

String jspPage = ParamUtil.getString(request, "jspPage");

//System.out.println("hello"+jspPage);

if (jspPage.equalsIgnoreCase(ProjectConstants.PAGE_PROJECT)) {

String orderByCol = ParamUtil.getString(request, "orderByCol",

"projectId");

request.setAttribute("orderByCol", orderByCol);

String orderByType = ParamUtil.getString(request, "orderByType",

"asc");

request.setAttribute("orderByType", orderByType);

//System.out.println("hello"+orderByCol+"aa"+orderByType);

}

}

• In JSP Page

List<Projects> projects = ProjectsLocalServiceUtil.getProjectses(0, ProjectsLocalServiceUtil.getProjectsesCount());

String orderByCol = (String) request.getAttribute("orderByCol"); 

String orderByType = (String) request.getAttribute("orderByType"); 

BeanComparator comp = new BeanComparator(orderByCol); 

List<Projects> projectsResults = ListUtil.copy(projects);

Collections.sort(projectsResults, comp); 

//System.out.print("column:"+orderByCol);

//System.out.print("type:"+orderByType);

if (orderByType.equalsIgnoreCase("desc")) {

Collections.reverse(projectsResults); 

}

• At Last add this attributes

<liferay-ui:search-container orderByCol="<%= orderByCol %>" orderByType="<%= orderByType %>" >

</liferay-ui:search-container>

Interface Concept In java

INTERFACE

• A Java interface is a bit like a class, except a Java interface can only contain method signatures and fields
• An Java interface cannot contain an implementation of the methods, only the signature (name, parameters and exceptions) of the method.
• You can use interfaces in Java as a way to achieve polymorphism.

For Exa.

public interface MyInterface {

    public String hello = "Hello";   //parameter
 
    public void sayHello();          // method signature
}

Loops in Java

• FOR LOOP

public class ForLoopExample {

public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("working");
for(int i=1; i<=50 ; i++){
int n = 2 * i;
System.out.println("2 * "+ i + " = " + n);
}
}

}

• WHILE LOOP

public static void main(String[] args) {

// TODO Auto-generated method stub

System.out.println("working");

int i = 0;

while (i < 50) {

 i++;

 int m = i*2;

        System.out.println("2 * "+ i + " = " + m);

        }

}

}

• DO WHILE LOOP

public static void main(String[] args) {

// TODO Auto-generated method stub

System.out.println("working");

int i = 0;

do {

 i++;

 int m = i*2;

        System.out.println("2 * "+ i + " = " + m);

        } while (i < 50);

}

}

OUTPUT:-
2 * 1 = 2
2 * 2 = 4
2 * 3 = 6
2 * 4 = 8
2 * 5 = 10
2 * 6 = 12
2 * 7 = 14
2 * 8 = 16
2 * 9 = 18
2 * 10 = 20
2 * 11 = 22
2 * 12 = 24
2 * 13 = 26
2 * 14 = 28
2 * 15 = 30
2 * 16 = 32
2 * 17 = 34
2 * 18 = 36
2 * 19 = 38
2 * 20 = 40
2 * 21 = 42
2 * 22 = 44
2 * 23 = 46
2 * 24 = 48
2 * 25 = 50
2 * 26 = 52
2 * 27 = 54
2 * 28 = 56
2 * 29 = 58
2 * 30 = 60
2 * 31 = 62
2 * 32 = 64
2 * 33 = 66
2 * 34 = 68
2 * 35 = 70
2 * 36 = 72
2 * 37 = 74
2 * 38 = 76
2 * 39 = 78
2 * 40 = 80
2 * 41 = 82
2 * 42 = 84
2 * 43 = 86
2 * 44 = 88
2 * 45 = 90
2 * 46 = 92
2 * 47 = 94
2 * 48 = 96
2 * 49 = 98
2 * 50 = 100

Liferay Interview Questions.....

1>Diff Between Hook And Ext?
2>what are the types of hooks?
3>mention the types of plugins in liferay?
4>explain service builder?
5>what is web content?
6>How to increase the size of column in liferay?
7>what are the possible DataTypes in Liferay?
8>How can you store image in Liferay Technology?
9>How To Embed One Portlet In another Portlet?
10>What is Liferay?
11>Diff Between 286 and 168 JSR Complaint?
12>What are users and usergroups?
13>explain IPC?
14>diff between dynamic query and custom query>
15>diff between liferay and other frameworks?
16>portal instance in liferay?
17>how to add portlet in control panel?

portal-ext.properties entries and Explanation

Place portal-ext.properties file below location or
liferay-portal-6.2-ce-ga2/tomcat-7.0.25
or

liferay-portal-6.2-ce-ga2/tomcat-7.0.25/webapps/ROOT/WEB-INF/classes


portal-ext.properties is used to override portal.properties file
and location of portal.properties file is

liferay-portal-6.2-ce-ga2\tomcat-7.0.42\webapps\ROOT\WEB-INF\lib\portal-impl.jar


This is used to override portal.properties file
1>passwords.encryption.algorithm = NONE
----------->This is used to Save password in normal form..By default Liferay Save passwords in encrypted format.

2>auto.deploy.enabled = true
--------------->This helps for autodeploy the plugin.

3>company.security.auth.type = emailAddress
------------>Default Authentication

4>company.security.auth.type = screenName
------------>This helps  the users to authenticate using Screen Name

5>company.security.auth.type = userId
------------->This helps the users to authenticate using user Id

6>theme.portlet.decorate.default = false
------------------> It will hide portlet border.

7>live.users.enabled = true
-------------->  to know number of live users 

8>openoffice.server.enabled = true
-------------->  To enable open office ,It will help to convert content into doc like pdf,doc etc 

9>terms.of.use.required = false
-------------> to disable the terms of use page

difference between string, string buffer and string builder in java.

String is an immutable class, so you cannot make changes on a String after creating it. All methods that do an operation on String returns a new one, subString(), toLowercase() etc. You can reinitialize it though, but this creates a new String in memory (as it should do).

This helps in many cases, most of the times you do not want to alter a String (in methods etc.). Unless you need to build a long text by appending new strings to a String. In this situation, you need to use StringBuilder or StringBuffer for memory's sake. These classes are mutable so a new String is not created on every append.

The main difference between StringBuilder and StringBuffer is thread safety. 
StringBuffer is synchronized, StringBuilder is not.
StringBuilder is faster than StringBuffer.

Liferay Plugins

There are different types of plugins available,

1. Portlet
2. Layout Template
3. Theme
4. Hook
5. Ext(Extension)
6. Web Content
7. Service Builder

Theme                 :- It helps to maintain Look & feel of  Liferay portal. 

Hook                  :- Is Used to customise core functionality of liferay.
Service Builder    :- A tool which is generally used to generate code to interact with database
Ext                 :-This is also used to customize core functionalitly.Hooks having some                 limitation beyond that we haveto use ext.if we use ext                                                   restart  would  be required.