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
}