Today's Question:  What does your personal desk look like?        GIVE A SHOUT

SEARCH KEYWORD -- JAVA APPLICATION DEVELOPMENT

  Permutation implementation in Java

Permutation is a very basic and important mathematic concept we learned in school. It has very practical applications in real world. For example, in football. In simple, permutation describes all possible ways of doing something. For example, there are six permutations of the set {1,2,3}, namely: (1,2,3), (1,3,2), (2,1,3), (2,3,1), (3,1,2), and (3,2,1). In general, for n items, there are n! number of permutations to arrange these items. How can we implement this algorithm in programming programm...

   Permutation,Implementation,Java,Sample     2015-03-26 02:18:14

  Hexadecimal and long in Java

Today I encountered a hexadecimal operation problem when I was implementing a bit reverse function for integer type. Basically in the implementation, there is an operation which is to do the bit operation & between one long integer and a hexadecimal number 0x00000000FFFFFFFFF. I was expecting that the high 32 bits of the long integer will be zeroed. But unfortunately I didn't get the expected result. The basic implementation is: long num=0x00F0_0000; num = (num>>16) | (num<<16); ...

   Hexadecimal,long,Java,bitwise operation     2014-06-18 23:44:32

  A boolean value interview question

Someone asked a question on StackOverflow, he was asked an interview question. The question is : Given 3 boolean variables a, b, c, return true if at least 2 out of the 3 are true. He gave the solution as follows :boolean atLeastTwo(boolean a, boolean b, boolean c) {    if ((a && b) || (b && c) || (a && c)) {        return true;    } else {        ret...

   bool,return,expression,conditional     2012-04-30 08:49:32

  Solution to getKeyCode() returns 0 in Java

The getKeyChar method always returns a valid Unicode character or CHAR_UNDEFINED. Character input is reported by KEY_TYPED events: KEY_PRESSED and KEY_RELEASED events are not necessarily associated with character input. Therefore, the result of the getKeyChar method is guaranteed to be meaningful only for KEY_TYPED events.For key pressed and key released events, the getKeyCode method returns the event's keyCode. For key typed events, the getKeyCode method always returns VK_UNDEFINED....

   Java,KeyCode,0,KeyListener     2011-06-06 10:38:11

  Who’s the winner: Python vs. Java, C/C++?

If there is one debate that never dies in the language community then it is this: Who’s the winner: Python Vs Java, C/C++. Obviously each has its own pros and cons, but in which language do the pros outnumber the cons or which language has better cons than others! For some it just comes down to familiarity, they like what they like!   The Numbers  But as far as the rest of the language world goes, the debate is still out there. By last count, Java, C and C++ were still winning. A...

   JAVA,INDIA,DEVELOPERS     2017-09-11 00:38:25

  Building Security onto Your Mobile Application

Analysts state that more than 75% of the mobile applications will fail the basic security tests in 2015 – Gartner Research. Enterprises that follow the Bring Your Own Device (BYOD) approach and facilitate mobile computing to their employees are susceptible to security threats and other vulnerabilities, unless they implement stringent security measures. In the development or deployment of mobile applications, a business can be severely impacted both financially and otherwise, if they are to...

   Web Application Development Company, iPhone App Development Company     2015-08-21 07:22:32

  Why exception would be thrown when deleting element while looping through HashMap in Java

HashMap and other Collection types are frequently used in Java application programming. This post will explain why exception would be thrown when deleting element with Map.remove() while looping through a Map using Iterator. This issue would also occur to other Collection types such as Set, List. Below is a sample code snippet demonstrating the exception thrown. Map<String,String> map = Collections.synchronizedMap(new TreeMap<String,String>()); map.put("key1","value1"); map.put("ke...

   JAVA,HASHMAP,CONCURRENTMODIFICATIONEXCEPTION     2018-06-30 12:49:09

  What will the value of Integer.valueOf(127) == Integer.valueOf(127) be in Java?

Do you really understand how Java does the integer comparison? OK, ignore the statements in the post title. What we are interested in is another set of comparison statements. Let's first see below code snippet. public class IntegerComparison { public static void main(String[] args) { Integer a = 127, b = 127; Integer c = 128, d = 128; System.out.println(a == b); System.out.println(c == d); } } What do you think the output will be? Are they both displaying true? You will find out t...

   JAVA,==,EQUALSTO     2018-01-13 22:18:15

  Standardizing Python WSGI deployment

Over the past year I have been testing all of the new python platform as a service companies that have popped up, and I have posted my notes on my blog so that everyone can learn from my experiences. ep.io, apphosted.com, gondor.io, dotcloud.com, DjangoZoom.com, Heroku, Django hosting roundup, All and all, the platforms were very similar, they allowed you to easily host your python/django project without having to worry about managing a server or other typical system administr...

   Python,Standard,WAR,Java     2011-12-31 15:39:44

  A HTTPS client and HTTPS server demo in Java

In this post, I will create a HTTPS server and HTTPS client demo which can establish HTTPS communication between a server and a client using Java. This should be very useful when we want to test our understanding about SSL communication. We will use both a detailed SSL client and a simple HttpsURLConnection as the HTTPS client. Before creating the actual HTTPS server and HTTPS client, we first need to generate the keystore and truststore to be used by the server and client. To generate the keyst...

   SSL,HTTPS,JAVA,DEMO     2015-10-23 09:04:36

RECENT