Is your pc working slow ... ?

Sometimes you get angry with your computerbecause if it slow. Now I'm going to tell you how to fix this problem. Here is the few tricks to do it.
01. Uninstall unwanted applications
If you installed more software's in your computer actually it's getting slow. so if have unwanted programs in your list uninstall all ofthem. To do it follow below steps.
• In Windows XP, go to Start -> Control Panel -> Add/Remove Programs
• In Windows 7 and Vista, go to Start -> Control Panel -> Programs -> Programs and Features
• In Windows 8 go to Settings -> Control Panel -> Programs and Features
02. Remove junk files
You don't even have to click a "Save" button once while using your computer to accumulate junk files. Simply checking emails, setting your computer to hibernate or surfingthe web will build up junk files on your computer. You can remove your PC junk files using Windows inbuilt "Disk Cleanup" utility.
• In Windows XP, Vista and 7 go to Start -> All Programs -> Accessories -> System Tools -> Disk Cleanup
• In Windows 8 Press Win+R and type Cleanmgr.exe on run. now press Enter
03. Disabling auto-start applications
Many programs will set themselves to auto-start when you boot your computer, even though you might only use them once a month. These background applications can take up a lot of RAM and they make your PC toslow. That's why disabling the auto-start option for programs you don’t need can do a lot to speed up your computer. Follow this steps to stop unwanted startup programmes.
• In Windows XP go to Start -> Run -> and type msconfig on run -> go to Startup tab. now you can uncheck unwanted startup programmes.
• In Windows Vista and 7 simply type msconfig in the search box in the Start menu
• In Windows 8 Press Win+R and type msconfig on run
04. Repair and defragment the registry
It is possible to repair registry errors yourself if you are a very experienced computer user or have a know the exact origin of your problem and step-by-step instructions to fix it. But many computer users can't repair registry errors themselves. So you can download third party software to do it. PC Tools Registry Mechanic is one of the best registry repair software.
05. Removing malware
Malware can also slow down your computer, running in the background and taking up system resources. To speed up your computer, install a good anti-malware product and set it to auto-update and run scheduled scans. There have many softwares to do it. I'm recommend Malwarebytes Anti-malware to do it.

Interfaces and Classes in Servlet

Interfaces in javax.servlet package:

• Servlet
• ServletRequest
• ServletResponse
• RequestDispatcher
• ServletConfig
• ServletContext
• SingleThreadModel
• Filter
• FilterConfig
• FilterChain
• ServletRequestListener
• ServletRequestAttributeListener
• ServletContextLitstener
• ServletContextAttributeListener

Classes in javax.servlet package:

• GenericServlet
• ServetInputStream
• ServletOutputStream
• ServletRequestWrapper
• ServletResponseWrapper
• ServletRequestEvent
• ServletContextEvent
• ServletRequestAttributeEvent
• ServletContextAttributeEvent
• ServletException
• UnavailableException

Interfaces in javax.servlet.http package:

• HttpServletRequest
• HttpServletResponse
• HttpSession
• HttpSessionListener
• HttpSessionAttributeListener
• HttpSessionBindingListener
• HttpSessionActivationListener
• HttpSessionContext (deprecated now)

Classes in javax.servlet.http package:

• HttpServlet
• Cookie
• HttpServletRequestWrapper
• HttpServletResponseWrapper
• HttpSessionEvent
• HttpSessionBindingEvent
• HttpUtils (depricated now)

History of Java

James Gosling, Mike Sheridan, and Patrick Naughton initiated the java language project in June 1991.
Originally designed for small. embedded systems in electronic appliances like set-top boxes. Initially called Oak was renamed as "Java". Java is just a name not an acronym.
Originally developed by james Gosling at SUN Microsystems( which is now a subsidiary of oracle Corporation) and released in 1995. JDK 1.0 released in (January 23,1996).

Servlet Interface

Servlet Interface provides common behavior to all the servlet  Servlet interface needs to be implemented for creating any servlet (either directly or indirectly). It provides 3 life cycle methods that are used to initialize the servlet, to service the requests and to destroy the servlet and 2 non-life cycle methods.

Methods of servlet Interface: There are 5 methods in servlet interface. The init, service and destroy are the life cycle method these are invoked by the web container.

• public void init(ServletConfig config) initializes the servlet. It is the life cycle method invoked by the web container only once.
• public void service(ServletRequest request, ServletResponse response) provides response for the incoming request. It is invoked at each request by the web container.
• public void destroy() is invoked only once and indicates that servlet is being destroyed.
• public ServletCofig getServletConfig() returns the object of ServletCofig.
• public String getServletInfo() returns information about servlet such as writer, copyright,version etc.

Example:

 import java.io.*;

import javax.servlet.*;

public class First implements Servlet{

ServletConfig config=null;

public void init(ServletConfig config){

this.config=config;

System.out.println("servlet is initialized");

}

public void service(ServletRequest req, ServletResponse res)throws IOException, ServletException{

 res.setContentType("text/html");

PrintWriter out=res.getWriter();

out.print("<html>");<body>");

out.print("<b>Hai</b>");

out.print("</html></body>");

}

public void destroy(){ 

System.out.println("Servlet is destroyed");

}

pulbic ServletCofig getServletConfig(){ 

return config;

}

public String getServletInfo(){

return "copyrith @ futureimpact"

}

HTML 5 TAGS Browser support

HTML 5:
  The below tags which are comes with HTML5 and which are supported in All Major browsers and not supported with.

Tags/Attributes	Browser support
contenteditable	All Browsers
contextmenu	present not supported any browser
accessKey	Not supported by Opera
draggable	IE8 and earlier versions, safari 5.1.2 Not supported

Contenteditable in HTML

Contenteditable :  It is new in HTML 5. This Attribute is supported in all major browsers. The contenteditable attribute specifies whether the content of an element is editable or not.

Syntax: < element contenteditable="true|false|inherit">

The attribute values of this contenteditable are true, false, inherit ( inherit specifies that the element is editable if its parent is)

Access Key in HTML

Access Key: To specify a shortcut key to access/focus a specific element in your HTML page use <accessKey>

This accessKey attribute works in all major browsers except Opera.

In HTML 5 the accessKey attribute can be used to any HTML element (it will validate on any HTML element.).

In HTML 4 the accessKey attribute can be used with <a> , <area> , <button> , <input> <label> ,  <legend> , <textarea>

The syntax:     <element accessKey="character">

Cascading Order

Multiple Styles Will Cascade into One  
Styles can be specified:

• inside an HTML element
• inside the head section of an HTML page
• in an external CSS file

Even multiple external style sheets can be referenced inside a single HTML document.

Cascading order:

What style will be used when there is more than one style specified for an HTML element?

Generally speaking we can say that all the styles will "cascade" into a new "virtual" style sheet by the following rules, where number 4 has the highest priority:

1. Browser default
2. External style sheet
3. Internal style sheet (in the head section)
4. Inline style (inside an HTML element)

So, an inline style (inside an HTML element) has the highest priority, which means that it will override a style defined inside the tag, or in an external style sheet, or in a browser (a default value).

Design Patterns Intro

The Design Pattern is not a framework and is not directly deployed via code.

Design Pattern have two main usages:

• Common language for developers: they provide developer a common langauage for certain problems. for example if a developer tells another developer that he is using a singleton, the another developer (Should) know exactly what is singleton.
• Capture best practices: Design patterns capture solutions which have been applied to certain problems. By learning these patterns and the problem they are trying to solve a un experienced developer can learn a lot about software design.

Design pattern are based on the base principles of object orientated design.

• Program to an interface not an implementation
• Favor object composition over inheritance

Design Patterns can be divided into:

• Creational Patterns
• Structural Patterns
• Behavioral Patterns

These patterns can divided into below shown:

Creational Patterns:

1. Factory Pattern
2. Abstract Factory Pattern
3. Singleton Pattern
4. Builder Pattern
5. Prototype Pattern

Structural Patterns:

1. Adapter Pattern
2. Bridge pattern
3. Composite Pattern
4. Decorator Pattern
5. Facade Pattern
6. Flyweight Pattern
7. Proxy Pattern

Behavioral Patterns:

1. Chain of responsibility Pattern
2. Command Pattern
3. Interpreter Pattern
4. Iterator Pattern
5. Mediator Pattern
6. Momento Pattern
7. Observer Pattern
8. State Pattern
9. Template Pattern
10. Visitor Pattern

Factory Pattern

Factory of what? of classes. In simple words, if we have super class and n subclasses, and based on data provided, we have to return the object of one of the sub-classes, we use a factory pattern.
Let's take an example to understand this pattern.

Example: Let's suppose an application asks for entering the name and sex of a person. If the sex is male(M), it displays welcome message saying Hello Mr. and if the sex is Female (F), it displays message saying hello Ms.
The skeleton of the code can be given here.

public class Person{
    //name string
   public String name;
      private String gender;

      public String getName() {
        return name;
        }

     public String getGender(){
    return gender;
     }

}

This is a simple class person having methods for name and gender. Now we will have two sub-classes, Male and Female which will print the welcome message on screen.

public class Male extends Person{
     public Male(String fullName){
       System.out.println("Hello Mr."+fullName);
     }
}

Also the class Female

public class Female extends Person{
   public Female(String fullName){
       System.out.println("Hello Ms. "+fullName);
     }
}
Now, we have to create a client, or a salutationFactory which will return the welcome messgae depending on the data provided. 

public class SalutationFactory{
 public static void main(String args[]){
     SalutationFactory factory=new SalutationFactory();
     factory.getPerson(args[0],args[1]);
}
public Person getPerson(String name, String gender){
     if(gender.equals("M"))
        return new Male(name);
else if(gender.equals("F"))
       return new Female(name);
  else
      return null;
   }
}

This class accepts two arguments from the system at runtime and prints the names.

Running the program:

After compiling and running the code on my computer with the arguments Srinivas and M:

java Srinivas M

the result returned is : "Hello Mr. Srinivas".

when to use a Factory Pattern?

the factory patterns can be used in following cases:

•  when a class does not know which class of objects it must create.
• a class specifies its sub-classes to specify which objects to create.
• In programmers language( very raw form), you can use factory pattern where you have to create an object of any one of sub-classes depending on the data provided.

Error: Your content must have a ListView whose id attribute is android.R.id.list

When you are creating A ListVIew Item in Android and want to display your selected item on Toast message. When you are running that app and if you get an error like below.

"Your content must have a ListView whose id attribute is android.R.id.list"

For the above problem answer is.

If your are using ListActivity then you must have ListView in your xml of layout and must be id of 

ListView is android.R.id.list




So must add listview in your layout like below code

android:layout_height="wrap_content"

android:layout_width="fill_parent"

android:id="@+id/android:list" />

In The Java Code it’l be get like this.

lv = (ListView) findViewById(android.R.id.list);

The $() factory function: in JQuery

All type of selectors available in jQuery, always start with the dollar sign and parentheses: $().

The factory function $() makes use of following three building blocks while selecting elements in a given document:

jQuery	Description
Tag Name:	Represents a tag name available in the DOM. For example $('p')selects all paragraphs in the document.
Tag ID:	Represents a tag available with the given ID in the DOM. For example$('#some-id') selects the single element in the document that has an ID of some-id.
Tag Class:	Represents a tag available with the given class in the DOM. For example $('.some-class') selects all elements in the document that have a class of some-class.

All the above items can be used either on their own or in combination with other selectors. All the jQuery selectors are based on the same principle except some tweaking.

NOTE: The factory function $() is a synonym of jQuery() function. So in case you are using any other JavaScript library where $ sign is conflicting with some thing else then you can replace $sign by jQuery name and you can use function jQuery() instead of $().

The Document Ready Event in JQuery

You might have noticed that all jQuery methods in our examples, are inside a document ready event:

$(document).ready(function(){
// jQuery methods go here...
});
This is to prevent any jQuery code from running before the document is finished loading (is ready).

It is good practice to wait for the document to be fully loaded and ready before working with it. This also allows you to have your JavaScript code before the body of your document, in the head section.

Here are some examples of actions that can fail if methods are run before the document is fully loaded:
Trying to hide an element that is not created yet
Trying to get the size of an image that is not loaded yet

Tip: The jQuery team has also created an even shorter method for the document ready event:

$(function(){
// jQuery methods go here...
});
Use the syntax you prefer. We think that the document ready event is easier to understand when reading the code.

How to use JQuery library

Here we can see that how to use JQuery in our HTML Page. If you don't want to download and host jQuery yourself, you can include it from a CDN (Content Delivery Network). Both Google and Microsoft host jQuery. To use jQuery from Google or Microsoft, use one of the following in alternate downloading:

JQuery Introduction

jQuery is a fast and concise JavaScript Library created by John Resig in 2006 with a nice motto:Write less, do more.
jQuery simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development.
jQuery is a JavaScript toolkit designed to simplify various tasks by writing less code. Here is the list of important core features supported by jQuery:

• DOM manipulation: The jQuery made it easy to select DOM elements, traverse them and modifying their content by using cross-browser open source selector engine calledSizzle.
• Event handling: The jQuery offers an elegant way to capture a wide variety of events, such as a user clicking on a link, without the need to clutter the HTML code itself with event handlers.
• AJAX Support: The jQuery helps you a lot to develop a responsive and feature-rich site using AJAX technology.
• Animations: The jQuery comes with plenty of built-in animation effects which you can use in your websites.
• Lightweight: The jQuery is very lightweight library - about 19KB in size ( Minified and gzipped ).
• Cross Browser Support: The jQuery has cross-browser support, and works well in IE 6.0+, FF 2.0+, Safari 3.0+, Chrome and Opera 9.0+
• Latest Technology: The jQuery supports CSS3 selectors and basic XPath syntax.

How to install jQuery ?
This is very simple to do require setup to use jQuery library. You have to carry two simple steps:
Go to the download page to grab the latest version available. Now put downloaded jquery-1.3.2.min.js file in a directory of your website, e.g. /jquery. The downloaded file name jquery-1.3.2.min.js may vary for your version. Your minified version would be kind of unreadable which would not have any new line or unnecessary words in it. The jQuery does not require any special installation and very similar to JavaScript, we do not need any compilation or build phase to use jQuery.

SubQueries in SQL hand book

  Sub Queries

Strings Hand Book

  Strings

file streams hand book

  File Streams

Exceptions tutorial

  Exceptions

Android Interview Questions

  Android Interview Questions