JAVA/J2EE interview Questions

Core Java Interview Questions

1. Can we call finalize() method?
2. Can we declare an anonymous class as both extending a class and implementing an interface?
3. How Observer and Observable are used?
4. What are the differences between boolean & operator and  & operator
5. What are transient variables in java?
6. What are Wrapper Classes?
7. What is an abstract method?
8. What is List interface?
9. What is synchronization
10. What is the difference between yield() and sleep()?
11. What is the difference between  time slicing and  preemptive scheduling ?
12. What is the initial state of a thread when it is created and started?
13. What is the use of the finally block?

JSP Servlets

1. Difference between GET and POST
2. What are the different ways for session tracking?
3. What is difference between custom JSP tags and beans?
4. What is servlet context?
5. What is servlet mapping?
6. What is session?
7. What is the difference between JSP and Servlets?
8. What mechanisms are used by a Servlet Container to maintain session information?

EJB (Enterprise Java Bean) Interview Questions

1. What is EJB?
2. What are different types of entity beans?
3. What are different types of session bean?
4. What are the different type of Enterprise JavaBeans?
5. What is a Stateful Session bean?
6. What is abstract schema?
7. What is an Entity Bean?
8. What is BMP (Bean managed persistence)?
9. What is CMP (Container Managed Persistence)?
10. What is Session Bean?
11. What is stateless session bean ?
12. When to use a stateless session bean?
13. When to Use Session Beans?
14. When to use Stateful session bean?
15. When we should use Entity Bean ?

JMS interview questions

1. What are the advantages of JMS?
2. What are the different parts of a JMS message?
3. What is asynchronous messaging?
4. What is Byte Message?
5. What is JMS?
6. What is Map message?
7. What is messaging?
8. What is object message?
9. What is Stream Message?
10. What is synchronous messaging?
11. What is text message?
12. What is the difference between Byte Message and Stream Message?
13. What is the difference between queue and topic?
14. What is the Role of the JMS Provider?
15. What type messaging is provided by JMS

JDBC interview questions

1. What is JDBC Driver?
2. What is JDBC?
3. What are stored procedures?
4. How do you handle your own transaction?
5. Is the JDBC-ODBC Bridge multi-threaded?
6. What are the different JDB drivers available?
7. What are the steps required to execute a query in JDBC?
8. What does Class.forName return?
9. What is a ResultSet?
10. What is cold backup, hot backup, warm backup recovery?
11. What is Connection pooling?
12. What is Connection?
13. What is DriverManager?
14. What is the advantage of denormalization?
15. What is the fastest type of JDBC driver?

General Questions

1. Can a method be static and synchronized?
2. Can an application have multiple classes having main method?
3. Can I have multiple main methods in the same class?
4. Describe the principles of OOPS
5. Difference between == and equals method
6. Expain the reason for each keyword of public static void main(String args[])?
7. Explain the Encapsulation principle.
8. Explain the Inheritance principle.
9. Explain working of Java Virtual Machine (JVM)?
10. How can I swap two variables without using a third variable?
11. How can one prove that the array is not null but empty?
12. How is it possible for two String objects with identical values not to be equal under the == operator?
13. How to convert String to Number in java program?
14. If you’re overriding the method equals() of an object, which other method you might also consider?
15. In System.out.println(), what is System, out and println?
16. What are different types of access modifiers?
17. What are Java Access Specifiers?
18. What are the differences between == and .equals()?
19. What do you understand by a variable?
20. What do you understand by casting in java language? What are the types of casting?
21. What do you understand by downcasting?
22. What do you understand by numeric promotion?
23. What if I write static public void instead of public static void?
24. What if the main method is declared as private?
25. What is a native method?
26. What is a static method?
27. What is Byte Code?
28. What is data encapsulation?
29. What is difference between String and StringTokenizer?
30. What is explicit casting?
31. What is implicit casting?
32. What is meant by pass by reference and pass by value in Java?
33. What is phantom memory?
34. What is reflection API? How are they implemented?
35. What is the difference between a while statement and a do statement?
36. What is the first argument of the String array in main method?
37. What is the Java Virtual Machine (JVM)?
38. What is the Locale class?
39. What is the ResourceBundle class?
40. What is the SimpleTimeZone class?
41. What type of parameter passing does Java support?
42. What would you use to compare two String variables - the operator == or the method equals()?
43. When is static variable loaded? Is it at compile time or runtime? When exactly a static block is loaded in Java?
44. Which class is the superclass of every class?
45. Why oracle Type 4 driver is named as oracle thin driver?
46. Why there are no global variables in Java?

NOTE: If you want answer to these questions or any selected question or have any query,then please leave your comment below with your email_id or mail me at blogwriters@rediffmail.com with proper subject and question.

Maa Sharda Images

Below we are providing images of Goddess Maa Sharda Temple which is photographed by me and it is from our tour to temple.


Please Note That If You Want A Detailed Description About MAA Sharda Temple then please CLICK HERE


                                             
                                                        Image of  Maa Sharda


                                                            

Take this image trip to Maihar Devi and make your first darshan here only.

Image1: When You approach towards Devi Darshan

                                           

Image2: When you were on entrance to get darshan

Image3: Devi Darshan of Maa Sharda       JAI MATA DI !!!!

Image4: Leaving after Devi Darshan

                                Image5: This is view from Temple at the top to the bottom road




                                          




                                   Image6: Trikut Pahad where Maa Sharda Temple is situated

Please don't hesitate to contact me if you need any help from me or information from me about Sharda Devi.

                                                               Jai Mata Di !!!!

Happy Blogging and Happy Darshan!!!!



                                          CLICK HERE for Knowing about MAIHAR DEVI



Regards,
Gaurav

What is PageRank?

Understanding PageRank

What is PageRank? Well to start with, it is a trademark of Google, *snort* who else?

A PageRank results from a "ballot" among all the other pages on the World Wide Web about how important a page is. A hyperlink to a page counts as a vote of support.

The PageRank of a page is defined recursively and depends on the number and PageRank metric of all pages that link to it ("incoming links"). A page that is linked to by many pages with high PageRank receives a high rank itself. If there are no links to a web page there is no support for that page.

If you'd really like to read the algorithm particulars, go HERE

The maximum amount of PageRank in a site increases as the number of pages in the site increases

The only way to increase the maximum is to add more inbound links and/or increase the number of pages in the site.

While I recommend creating and adding new pages to increase a site's total PageRank so that it can be channeled to specific pages, there are certain types of pages that should not be added. These are pages that are all identical or very nearly identical and are known as cookie-cutters. Google considers them to be spam and they can trigger an alarm that causes the pages, and possibly the entire site, to be penalized. Pages full of good content are a must.

Outbound links are a drain on a site's total PageRank. They leak PageRank. To counter the drain, try to ensure that the links are reciprocated. Because of the PageRank of the pages at each end of an external link, and the number of links out from those pages, reciprocal links can gain or lose PageRank. You need to take care when choosing where to exchange links.

To a spider, www.domain.com/, domain.com/, www.domain.com/index.html and domain.com/index.html are different urls and, therefore, different pages. Surfers arrive at the site's home page whichever of the urls are used, but spiders see them as individual urls, and it makes a difference when working out the PageRank. It is better to standardize the url you use for the site's home page. Otherwise each url can end up with a different PageRank, whereas all of it should have gone to just one url.

And after all of that info has crossed your eyes, you can check your site's PageRank HERE. And you can even grab Google's handy code to put the PageRank live on your site!

How to make Google Spider to crawl your blog?

Google Spiders Everywhere

We've already discussed how to sign up for the search engines, including Google. See the post about Search Engines or click on the Label that I made for it or click here.

Today I'm going to go through what it takes to make sure that your site is being crawled correctly by the spiders...LOL...That sounds cool, doesn't it?

One of the first things you need to be aware of is Google Blog Search Ping Service. You can ping your blog here to get Google to crawl it.

Then after you ping your blog, go and check for it to register onGoogle Blog Search. Now if it doesn't show up right away, don't worry!

Go sign yourself up with Google Alerts. When you sign up for this put the URL (address of your blog) in the top box, where it says search terms. The when your blog updates, you can tell how long it takes the spiders to crawl your blog, because Google will send you an email, every time you update!

Next thing...and I've addressed this in the Search Engine post is your site map. You can set this up with Google WebMaster Central. Now I can't say enough good stuff about these tools on this site. You can set up your site map, you can find out if your site is being indexed by Google, a Help Center, and multiple other tools!

I gave you instructions before on how to setup your site map, but make sure that when your done you get the little (1) on the column that says site map. After you've set up your site map, check the crawl rate.

Click on the tool for setting up a site map. This will be the page where you get the little (1) under the site map column. Click on the title of your blog and it takes you to the Diagnostics page that tells you all about your crawl rate, the errors, and tools.

Your crawl rate should be set to normal because it will tell you that at the slower rate: "A slower crawl will reduce Googlebot's traffic on your server, but we may not be able to crawl your site as often."

How Can I Make My Website or Blogs Searchable by Search Engines?

Search Engines

If you want to be seen by the world, you need to be seen by the internet search engines.

Okay, so what's a search engine...LOL...the little train that could...no! A search engine is defined as an information retrieval system designed to help find information stored on the World Wide Web.

How does this little engine work? Search engines on the internet store large amounts of information from web pages. They search the web and retrieve this information using a Web crawler (aka... a spider)*shudder* spiders creep me out, even when their virtual! A Spider is an automated Web browser that follows every link it crawls over.

And last but not least, why the devil is this important? It's important because it helps people to find your website, find your content, find what you want the world to know.

Okay...I'm hooked you say! How do I sign up! I'll admit, Goggle is my favorite, but there are others...go sign up with all of them to optimize your chances of being seen.

GO HERE FIRST!!! My new favorite is 

They submit it to more that 40 search engines for you, and they have great free Search Engine Optimization and SEO Tools! They will also teach you how to make Meta tags for your template!!! These are the things that you need to do first before you have little webspiders crawling all over your pages picking up useless information...you want to be OPTIMIZED!!

Google is the next one to do.

Go to: 
Google Webmaster Tool

Put the URL of your blog in the box in the upper right hand corner...click enter
A new page opens that says, "Next step - Verify" Click there.

Another page opens up...choose verification method...choose - add a Meta Tag.

A box opens with a tag written in bold. Copy and paste that into your template, in the first section, (I put it right below that declaration so that I could find it easily!) before the first section. Save template change. (keep this Google page open!)

Now go back to the Google page and click verify. It will tell you verified!
Under the words Webmaster Tools at the top of the page, click on "My Sites".

Click on "Add a sitemap" it will be on the same line as your blog address.
Under "Choose Type", select "Add General Sitemap".

In the empty box, copy:

http://YOURBLOGNAME.blogspot.com/rss.xml

(YOURBLOGNAME) should be the name of your blog! Click Add Web Sitemap.

Go HERE to sign up at Yahoo Site Explorer. After you enter your site address over on the right hand side there is a green button that says Authenticate. Click and follow the directions. Use the Meta tag option like you did for Google.

Now go back to the Site Explorer page and click the word "Manage" that is in front of your blog name.

It will go to a page with your blog name and an empty box.

In the empty box add: feeds/posts/full, click "Add feed".

Another of my favorite search engines is Technorati. Go here to the Technorati Sign Up. After filling out the form, check "I have a blog to sign up now", then click Join.

On the new page, at the bottom is a box to put in your URL (blog address), then click! It will give you a small box of code that you need to embed in your template

Choose your claim method. I like embedded claims because you'll be able to customize a widget for your blog to feature a "search this blog" box, a "blogs that link here" link, or profile information. AND I LOVE WIDGETS!!

Log in to your Blogger account in a new window. Go Dashboard>>>Layout...create a HTML widget to hold the code in your sidebar. Click "Save Template Changes". When you're all done with that click the button on the bottom of the Technorati page to proceed. This releases the spiders *snort*!

THESE ARE ALL METHODS OF SIGNING UP TO BE INCLUDED IN SEARCH ENGINES...but if for some reason you don't want Blogger.com to index your blog.

Open your blog. Go Dashboard>>>Settings>>>Basic>>>Add your Blog to our listings? No>>>Save settings.

How To Remove The Blogger Navigation Bar

Hi Guys!!!! 

                This the latest tips and tricks for our newcomers on bloggers who want to remove there pre-defined bloggers navigation bar.So for those who don't have any idea about this, for them we will become little informative.Lets start....

A lot of people who host their blogs on Blogger (www.blogspot.com) complain about the inability to remove the blogger navigation bar via their elements page. Indeed, if that's where you are looking, the only thing you'll be able to do from there is change the color to one of several pre-determined selections.

If you really want to remove the blogger navigation bar, you need to access your HTML template. Before I tell you how to do that, however, I'd like to first talk about why you may or may not want to remove the nav bar from your blogspot blog.


      Main Reasons To Remove Navigation Bar

• It looks more professional without it: Depending on what your purpose for blogging is, you may choose to remove the blogger navbar because having one makes a blog look more like a free-hosted blog and less like a professional site worth taking seriously.
• It gives you more space at the top of your page: This may not seem significant, but not having the navbar there does give you a bit more space for graphics. I have found this space to be quite useful when designing my own blogs.

      Main Reasons To Keep Navigation Bar

• It makes editing a little bit easier: You can login directly from the blog itself, and don't have to worry about logging into blogger. You can also edit capsules from the main page, without having to go into elements.
• You get a little bit of traffic from the "next blog" button: And I do mean teenie. I can't even recall the last time I saw traffic from it.
  
  
  

  How To Remove Navigation Bar

  
  

  (Step by Step Process)

  If you've decided that you definitely want to remove your blogger navbar, it's actually a very simple process that any non-technically-inclined person can accomplish with ease. Just follow these steps:

  1. Login to your blogger dashboard.                                        Snapshot of The Code                          
  

  

  2. Then Click "Layout" or "Design"

  3. Then Click "Edit HTML"

  4. Find the BLUE code you see in the image to your right. The code will be quite near the top of your HTML section, you shouldn't have to scroll very far at all. The blue code should definitely be there, but the data box you see may not be, depending on where your template came from.

  5. ADD the code you see in red precisely where you it see it in the image to your right. If you want to copy and paste it, do so from the bold text you see below:

  #navbar-iframe {
  display: none !important;
  }
  

  
  

  
  Preview It First!
  
  
  Use your preview button before you click save! If you like what you see, go ahead and save otherwise change it to its previous state by undo-ing it(or press Ctrl+Z) before leaving the page.
  
  
  What happens if I want the nav-bar back in the future?
  
  
  Simply go back into your HTML the same way and delete the part you just added. It's really that simple!
  For this I suggest please download a copy of your original template to your own system and then make any change to the copy available live on blogger, so that if any occur (or your mood changes) you will be able to rectify that.
  
  
  Happy Reading and we will meet in next post also keep comment (and mailing) to know about latest tips and tricks!!!!
  
  
  Regards,
  Bunty
  
  

How to earn money on internet?

Hi Guys!!!!
                       I received many questions from your side and I am very happy to answer all those questions which is important to you all.So today I will one very important question which every beginner want to know and the question they ask me is:


I want to ask how to register with Google for Google Adsense, i want to add it on my site and earn money?


Sign up for Adsense at http://www.google.com/adsense 

Adsense is a way to monetize and earn money from your site by putting Google ads from their advertising network Adwords. It has been around since June 2003 and Adsense has allowed many website owners to earn from their sites. I highly recommend going through the Adsense Quick Tour to learn more about the program http://www.google.com/services/adsense_tour/index.html 

HOW DOES IT WORK 

You apply and once you get approved, you can put in the Adsense code in your site. Here are the instructions on how to add Adsense codes on your site https://www.google.com/adsense/support/ ... topic=8434 

You earn through various ways: 

1. Pay per click - this is the common way to earn which is you earn every time a visitor clicks on your ads 
2. Pay per impression - an advertiser can specifically target your site and show ads where you earn via cost per 1,000 impression (e.g. you earn every time someone sees your ad, even though they don't click on it) 
3. Adsense for feeds 
4. Adsense for search 
5. Adsense for mobile 

WHAT PERSONAL INFO DO I HAVE TO GIVE? 

In the application form https://www.google.com/adsense/g-app-single-1 you will give 

- your name 
- your address 
- if your country qualifies for electronic fund transfer and you wish to be paid by EFT, your bank details 
- your SSN or tax account number if you are in the US as Google reports Adsense income to the IRS 

IS IT WORTH IT AND HOW MUCH MONEY PER MONTH DOES IT BRING IN? 

Some sites do very well with Adsense (even in the millions of dollars a year) while many more sites do extremely poorly with the program (can't even earn $10 a month). One of the misconception people have about Adsense is they simply slap it in their websites and it will automatically earn them big money -- which is not true as evidenced by the many disgruntled webmasters 

Your income will depend on: 

- the topic of your site (if you have high paying keywords you stand to earn more) 
- responsiveness of users to ad (are visitors coming to your site with blinders in their eye or do they look at the ads as additional complementary resource) 
- traffic (you earn more with more traffic, even if you have low paying keywords or other metrics) 
- how you implement the ads on your site (some positions and colors work better than others) 

I suggest you join the program (you've got nothing to lose as it is free) and see how your site will do with it.


Till next post Enjoy Surfing!!!!


Regards,
Golu
[--Guest Writer]

How to add my site to a search engines like yahoo, google or windows live (or msn)?

Hi guys!!
             Today I am going to tell you how to submit your sites to biggest search engines like google, yahoo, etc.
and provide link to them and also some SEO tips.So, Lets begin....


To add your site to Google 

http://www.google.com/addurl/?continue=/addurl 

To add your site to yahoo 

http://search.yahoo.com/info/submit.html 

To add your site to MSN 

http://search.msn.com/docs/submit.aspx?FORM=SUNO To add your site to DMOZ (Directory Mozilla) an ODP (Open Directory Project) approach


http://www.dmoz.org/


You can submit your site to these major sites yourself. But to rank at the top, you need to advertise it. You can try Google Adwords. It’s the most effective and targeted way of Advertising.I've personally tried it and its worth.

You can also try free classified advertising. 

Some SEO Tips 

1. Add content 
Add content, add content, and add content. Before you even register your domain, you should have enough ideas to build 100 pages on your site. Start brainstorming and see what you can come up with in 10 minutes. If that's not enough to fill 50 pages, consider not building the site at all. Having lots of content is important. 

2. A simple design is better 
Text content should outweigh the html content. Stay away from heavy flash, java, JavaScript, etc. Don't add to much stuff like 'best viewed with'... Your website should be viewable with any browser. Keep it clean and professional. 

3. Keep the pages small 
Smaller is better. Keep it under 15k if you can. Your site should be fast loading, or people will leave. Speed is everything. Next to content, that is. Keep it under 10k or 5k if you can. Difficult, but people love fast sites. Throw away all the trash on your pages. 

4. Content length 
Put a new page online every day of about 200 to 500 words. Go to the overture keyword suggester to find ideas of what to write about. Spell checks your content. Search engines can do it, and so should you. If you have a blog, go for article-like posts as opposed to the personal diary kinds of posts. 

5. Use keywords 
Use your keywords in the following places: title, description tag, heading, url, once bold, once italic and once high on the page. 

6. Link to other sites 
Put 2 links to other, high ranking pages on your site. They should be relevant to the content of that page and use keywords as your link. Don't add every link that's requested. Check their relevance first. 

7. Link to your own site 
Put links from one page to other relevant pages on your own site. Again: use keywords as your link. 

8. Submit your site 
Submit your site to Google, AltaVista, Yahoo, Msn, Hotbot, etc. Then forget about that for 6 months. Also submit it to every single directory you can find. Do a check after 6 months and resubmit if you're not listed. 

9. Log and track 
Most hosts provide these. Don't use a lame graphic counter. Check where your visitors are coming from to find out what traffic methods work best for your site. 

10. Write for people 
People are not coming to your site for your content. They are coming for their content. Try to write as if you are writing to one specific person, such as a friend of yours who's interested in the same topic. Don't try to write for 'all of your visitors'. 

11. Stay ahead 
If you know that something big will come out in a few months, build a page about it now. It gives search engines time to index that page so they can feed it to the growing anticipating crowd. 

12. Add more content 
This is so important: keep adding content. Do this for a year and your site will be a top ranking website within one year. You could've been there now, if you started last year. So start now, so you'll be there next year. You'll thank yourself (and me) later.


NOTE: Please mail me at mailme.freebooks@rediffmail.com or at gsingh4g@gmail.com  with the subject as "search engines link" and also mention Blog Name as Gaurav's Blog ,if you want some other search engines name and links to add/list your website there.You can also leave comments below.


Till next post Enjoy Reading!!!!


Regards,
Gaurav

How to get multiple Facebook accounts?

Hello Dear!!!!

               Welcome you all to the Land of Knowledge!!!!

Many years back when me and my friends have joined the facebook, the best social networking sites in the world which generates second largest revenue from websites running across the globe, we always thought of how to get multiple facebook accounts?  We got one very popular and well-known idea (which you all must have) and that is:

create as many accounts as we can and then signup with facebook....

is it more difficult or tedious to remember different email-id's and there password????

But don't worry I have the idea and I want to commit that you all like this because :

1.  it is easier
2. no need to remember different email-ids
3. it is a trick
4. very helpful for those who want multiple facebook account

So, lets begin....!!!!

How to make multiple facebook account with single email address

I know that many people want to ask me :

 "Is it possible to make multiple facebook accounts with single email address ?" 

My answer for them is :

"Yes" you can make multiple facebook account with single email address if you have a gmail email address , with this gmail id and following a small Gmail trick you can make multiple facebook accounts .

As many of you don't know that :

There is a small bug in Gmail because of which Gmail ignores the dot (.) in the email address, so following email addresses in gmail are actually the same.

example.123@gmail.com
exam.ple123@gmail.com

e.xample.123@gmail.com

If you have a gmail id you can test it yourself by sending email to that address by changing the positions of dot.

Hence, I can say that the trick  is: sign up to facebook with your gmail email address by changing the positions of dot (.)  and all those facebook accounts  will be actually associated with the single gmail account.

I must advice that if you want multiple facebook accounts hurry up before facebook knows about this Gmail bug or google knows get information about this bug.


Till then enjoy reading and accessing you social networking sites!!!!


Regards,
Gaurav