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Java String 101 - Everything You Want to Know about String in Java

someone might question that why do we need another article about string in Java, haven't we had enough about the string is already written? Yes, I agree there are a lot of articles related to Java string covering topics like how to use Java String, an example of Java string and almost everything you can do with string in Java. But, I wanted to document my experience of using String in Java and some nasty and little-known things I discovered about the Java String class, which may not be obvious to many Java developers. A string is available in almost every programming language and its probably the most used data structure or a data type, hence a good knowledge of String is very important for every Java developers.

5 ways to redirect a web page using JavaScript and jQuery

When an HTTP request for one page automatically goes to another page then it is called a redirection. The redirection of a web page is used for different reasons e.g. redirecting to a different domain e.g. when you move your website from one URL to another URL or redirecting to a more recent version of a page you are looking at it. There are many ways to redirect a web page and different web technologies provide different ways e.g. Java provides sendRedirect() and forward() method for redirection. The redirection can also be divided into two categories, client side and server side. In client side, redirection client is responsible for routing request to another URL but in server side redirection, its server's job to redirect to a new page.

How to join two threads in Java? Thread.join() example

You can join two threads in Java by using the join() method from java.lang.Thread class. Why do you join threads? because you want one thread to wait for another before starts processing. It's like a relay race where the second runner waits until the first runner comes and hands over the flag to him. Remember, unlike sleep(), join() is not a static method so you need an object of java.lang.Thread class to call this method. Now, who calls and who wants, and which thread dies? for example, if you have two threads in your program main thread and T1 which you have created. 

Difference between == and === Equal Operator in JavaScript

In one of the recent JavaScript interview for a Java web development position, one of my readers was asked this questions, What is the difference between comparing variables in JavaScript using "==" and "===" operator?  My reader got shocked because he was from Java background and doesn't have great exposure to JavaScript, though he was pretty much familiar with some JavaScript function, event handling, and some jQuery tricks, he wasn't aware of subtle details of JavaScript. He did the right think, politely said that he is not aware of the difference between == and === operator. Though It did not affect his interview performance much, he was keen to know about this as soon as he finished his interview. He asked to me as well, and that's the reason of this post. 

How to stop a thread in Java? Example

Today we're going to learn about how to stop a thread in Java. It's easy to start a thread in Java because you have a start() method but it's difficult to stop the thread because there is no working stop() method. Well, there was a stop() method in Thread class, when Java was first released but that was deprecated later. In today's Java version, You can stop a thread by using a boolean volatile variable.  If you remember, threads in Java start execution from the run() method and stop, when it comes out of the run() method, either normally or due to any exception. You can leverage this property to stop the thread. All you need to do is create a boolean variable e.g. bExit or bStop. Your thread should check its value every iteration and comes out of the loop and subsequently from run() method if bExit is true. 

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver [Solution]

Problem : You are getting java.lang.ClassNotFoundException: com.mysql.jdbc.Driver error while connecting to MySQL database from Java Program. You may be running your Java application directly from command prompt, shell script, ANT or Eclipse.

Cause : In order to connect to MySQL database, you need JDBC driver for MySQL. A class which implements java.sql.Driver interface for MySQL. Every vendor is responsible to implement this class for their databases. This driver implementation is provided by MySQL as MySQL java connector library. There is a class called com.mysql.jdbc.Driver which implements this interface.

Difference between OCAJP7, OCAJP8, and OCAJP11 Certification - 1Z0-803 vs 1Z0-808 vs 1Z0-815

One of the frequently asked questions asked by most of the OCAJP certification candidates is, what are the differences between OCAJP 8 and OCAJP 7? And, after Java 11 certification release, what is the difference between OCAJP 11 (1Z0-815) and OCAJP 8 (1Z0-808) Which one Java developers should go for? OCAJP7 or OCAJP8, or OCAJP 11? The obvious answer to this question is the latest Java version of the exam, I mean OCAJP 11. Since it's already more than a couple of months since Java 12 is out but there is no OCAJP 9 certification, the OCAJP 8 should be the exam, Java developer should pursue this year and beyond. The question is more for those who are looking to become certified Java developer in quick time and doesn't know Java 8 yet like experienced Java developers who have extensively worked in Java SE 6 and prior version but don't have any Java certification yet.

Difference between Type 1, 2, 3 and 4 JDBC Driver in Java?

One of the oldest Java interview question is what is the difference between different types of JDBC drivers e.g. what is the difference between type 1, type 2, type 3 or type 4 drivers? Sometimes also asked as how do you choose between different JDBC driver? When to use type 3 over type 4 driver etc. It's 2015 now and I doubt anyone is using JDBC driver other than type 4 for connecting to database, but let's see how to answer this question when you face it during the interview. The difference between different types of JDBC driver comes from the fact how they work, which is basically driven by two factors, portability, and performance. Type 1 JDBC driver is the poorest in terms of portability and performance while type 4 JDBC driver is highly portable and gives the best performance. You will learn more differences between different JDBC drivers as we go along.

Can you join two unrelated tables in SQL? Cross Join Example

In one of the recent programming job interview, one of my readers was asked the question, how do you join two tables which are not related to each other? i.e. they don't have any common column? is it possible in SQL? My reader got confused because he only knows about INNER join and OUTER join which require a key column like dept_id which is the primary key in one table like Department and foreign key in another table like Employee. He couldn't answer the question, though he did tell them about you can select data from multiple tables by typing multiple table names in from clause using a comma. What he was saying was right, but he didn't know much about it, so he couldn't explain it confidently. Lucky for him, he got the job but he emailed me asking the same question which inspired me to write this post.