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What are the types of cookies?

Cookies can be broadly classified into 2 types

1. Persistent cookies: Remain on the client computer, even after the browser is closed. You can configure how long the cookies remain using the expires property of the Http Cookie object.

2. Non-Persistent cookies: If you don't set the Expires property, then the cookie is called as a Non-Persistent cookie. Non-Persistent cookies only remain in memory until the browser is closed.

There two type of cookies ..
 Persistent cookies: cookies are stored on your computer hard disk. They stay on your hard disk and can be accessed by web servers until they are deleted or have expired. 
public void SetPersistentCookies(string name, string value){
 HttpCookie cookie = new HttpCookie(name);
 cookie.Value = value;
 cookie.Expires = Convert.ToDateTime(“12/12/2008”);
 Response.Cookies.Add(cookie);}

Non-persistent cookies: cookies are saved only while your web browser is running. They can be used by a web server only until you close your browser. They are not saved on your disk.
 public void SetNonPersistentCookies(string name, string value){
 HttpCookie cookie = new HttpCookie(name);
 cookie.Value = value;
 Response.Cookies.Add(cookie);}

What is a NullPointer Exception in asp.net and how to fix it

Null pointer exception means you are trying to access a member field or a function from an object which is null. for example you created a object of a class object name is "ClassAobj" and you want a variable value from class which is assign and initilize in that class now int a = ClassAobj.Number1; if "ClassAobj" is null then you can not access the value of Number1 . for fixing it ,either you have to initilize the class or you have to full if condition if(ClassAobj != null) { int a = ClassAobj.Number1; }

You are trying to use something that is null (or Nothing in VB.NET). This means you either set it to null, or you never set it to anything at all.

Like anything else, null gets passed around. If it is null in method "A", it could be that method "B" passed a null to method "A".

The rest of this article goes into more detail and shows mistakes that many programmers often make which can lead to a NullReferenceException.

How do you create a Persistent Cookie?

You create a persistent cookie the same way as session cookies except that you set the Expires property to a Date in the future which will store the Cookie to the client computer hard drive.

//Code to create a UserName Persistent Cookie that lives for 10 days
HttpCookie CookieObject = new HttpCookie("UserName", "David");
CookieObject.Expires = DateTime.Now.AddDays(10);
Response.Cookies.Add(CookieObject);

//Code to read the Cookie created above
Request.Cookies["UserName"].Value;

Cookies have an expiration date implicitly or explicitly set which controls how long they last (subject to the user agent actually enforcing it). A cookie may persist only for the duration of the session (or an even shorter period).

If a cookie is valid, it will be passed along with the HTTP request to the domain that it originated from. Only the domain that set the cookie can read the cookie (though there are ways to exploit this, such as cross-site scripting).

  • If you want a cookie to expire at a specific time, set an expiration date on it using the client or server-side language of your choice.

  • If you want the cookie to expire when the session ends, don't set an expiration date.

Why do we use jQuery?

  • Easy to use and learn.
  • Easily expandable.
  • Cross-browser support (IE 6.0+, FF 1.5+, Safari 2.0+, Opera 9.0+)
  • Easy to use for DOM manipulation and traversal.
  • Large pool of built in methods.
  • AJAX Capabilities.
  • Methods for changing or applying CSS, creating animations.
  • Event detection and handling.
  • Tons of plug-ins for all kind of needs.

These are just a few reasons. But the bottom line is the jQuery is becoming the standard for DOM manipulation, simple effects, and much more.

  • Well maintained - Documentation, examples, it's all there.
  • Browser compatible - You don't worry about it.
  • Easy to learn - Spend more time coding!
  • Large community - The answer is always on Stack Overflow.
  • It's correct - It does a lot of small things correctly so you don't have to.
  • Extendable - Tons of community plugins for value.

Why Constructor name is same as Class name

Constructor is called immediately after an object of a class is created. To reduce the number of keywords in Java, name of the constructor is defined same as the Class name. The Java developers don't want to include new keyword for constructor. They want to keep it simple and precise.
So that it can be unambigously identified as the constructor. and how its get invoked implicitly when we create object of that class. It is invoked by the compiler because it has already been unambiguously identified because of its naming sheme.

Its more of a convenient convention rather than a logical reason. Methods in a class which have the same name as the class name are constructors - the easiest and simplest way to identify a method as a constructor. This is much better than telling the compiler about the constructor methods using config files or using annotations over methods…

Rest API Authentication in Java

In token-based authentication, the client exchanges hard credentials (such as username and password) for a piece of data called token. Instead of sending the hard credentials in every request, the client will send the token to the server to perform authentication and authorization.

 in this RESTful services tutorial, we will see about how to do HTTP basic authentication. There are many ways to implement authentication in RESTful web services. HTTP basic authentication is the first step in learning security.

http://javapapers.com/web-service/restful-services-http-basic-authentication/

What is difference between config() and run() method in AngularJS? which runs first ?

AngularJS   .Config() Method - configuration gets executed during the configuration phase. We can inject providers and constants into configuration block. This block is used to inject module wise configuration settings to prevent accidental instantiation of services before they have been fully configured.

AngularJS  .Run method – Run method is executed after the configuration method. we can inject instances and constants in run method. The run method is a great place to put event handlers that need to be executed at the root level for the application. For example, authentication handlers.

Configuration():  get executed during the provider registrations and configuration phase. Only providers and constants can be injected into configuration blocks. This is to prevent accidental instantiation of services before they have been fully configured.

Run(): get executed after the injector is created and are used to kickstart the application. Only instances and constants can be injected into run blocks. This is to prevent further system configuration during application run time.Run blocks are the closest thing in AngularJS to the main method. It is executed after all of the services have been configured and the injector has been created. Run blocks typically contain code which is hard to unit-test, and for this reason should be declared in isolated modules, so that they can be ignored in the unit-tests.

Advantages of Rational ClearCase over other SCM tool i.e Microsoft Visual Source Safe

1. In ClearCase Check-in's are atomic.
2. Directories are first-class controlled entities in 
Clearcase. Even supports controlling of symbolic/hard links.

As with the ClearCase Bridge, you are continuing to use ClearCase for versioning, and are using RTC for change request management, task management, and planning.   With the Clearcase importer (either the Version Importer or the Baseline Importer), you are using RTC for versioning as well, and only using Clearcase for occasional access to archived versioned information that was not imported into RTC. In Clearcase performance is better supports more data size.


VSS Performance is poor and supports less data size.Directories are first-class controlled entities in clearcase. Even supports controlling of symbolic/hard links and The multisite is the best part of clearcase than any other 
tool.

In CLearcase performance is better supports more data size..

VSS Performance is poor and supports less data size.....

Explain servlet life cycle.

A servlet life cycle can be defined as the entire process from its creation till the destruction. The following are the paths followed by a servlet.

  • The servlet is initialized by calling the init () method.
  • The servlet calls service() method to process a client's request.
  • The servlet is terminated by calling the destroy() method.
  • Finally, servlet is garbage collected by the garbage collector of the JVM.
The web container maintains the life cycle of a servlet instance. Let's see the life cycle of the servlet:
  1. Servlet class is loaded.
  2. Servlet instance is created.
  3. init method is invoked.
  4. service method is invoked.
  5. destroy method is invoked
there are three states of a servlet: new, ready and end. The servlet is in new state if servlet instance is created. After invoking the init() method, Servlet comes in the ready state. In the ready state, servlet performs all the tasks. When the web container invokes the destroy() method, it shifts to the end state.

1) Servlet class is loaded

The classloader is responsible to load the servlet class. The servlet class is loaded when the first request for the servlet is received by the web container.

2) Servlet instance is created

The web container creates the instance of a servlet after loading the servlet class. The servlet instance is created only once in the servlet life cycle.

3) init method is invoked
The web container calls the init method only once after creating the servlet instance. The init method is used to initialize the servlet. It is the life cycle method of the javax.servlet.Servlet interface. Syntax of the init method is given below:
  1. public void init(ServletConfig config) throws ServletException  
 

4) service method is invoked

The web container calls the service method each time when request for the servlet is received. If servlet is not initialized, it follows the first three steps as described above then calls the service method. If servlet is initialized, it calls the service method. Notice that servlet is initialized only once. The syntax of the service method of the Servlet interface is given below:
  1. public void service(ServletRequest request, ServletResponse response)   
  2.   throws ServletException, IOException  
 

5) destroy method is invoked

The web container calls the destroy method before removing the servlet instance from the service. It gives the servlet an opportunity to clean up any resource for example memory, thread etc. The syntax of the destroy method of the Servlet interface is given below:
  1. public void destroy()  
 
  1. Loading Servlet Class : A Servlet class is loaded when first request for the servlet is received by the Web Container.
  2. Servlet instance creation :After the Servlet class is loaded, Web Container creates the instance of it. Servlet instance is created only once in the life cycle.
  3. Call to the init() method : init() method is called by the Web Container on servlet instance to initialize the servlet.

    Signature of init() method :

    public void init(ServletConfig config) throws ServletException
    
  4. Call to the service() method : The containers call the service() method each time the request for servlet is received. The service() method will then call the doGet() or doPost() methos based ont eh type of the HTTP request, as explained in previous lessons.

    Signature of service() method :

    public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException
    
  5. Call to destroy() method: The Web Container call the destroy() method before removing servlet instance, giving it a chance for cleanup activity.

How to import CSS using system import in Angular JS 2.0?

you can call like following

@import 'MystleClass.css';

@Component({ templateUrl: 'card.html', styles: [` .card { height: 70px; width: 100px; } `], encapsulation: ViewEncapsulation.Native // encapsulation: ViewEncapsulation.None // encapsulation: ViewEncapsulation.Emulated is default })