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

SEARCH KEYWORD -- Java software development



  The Greatest Regex Trick Ever (Simplified)

There is a post which is really hot recently which showcased a best ever regular expression trick. In this post, it provides a trick which can be adapted to situations where one wants to match some patterns desired and exclude the patterns undesired. In simple, the trick is : Pattern not desired | (Pattern desired) Then taking the group 1 match of the capturing group of matched. This group will contain the strings matching the desired patterns. Have to say this trick is really neat and brilliant...

   REGULAR EXPRESSION,PROGRAMMING,JAVA     2015-10-01 21:59:05

  The difference between System.load and System.loadLibrary in Java

When writing code using native library in Java, normally the first step is loading some native library. static{   System.load("D:" + File.separator + "Hello.dll"); } JDK provides two ways to load libraries: System.load(String filename) System.loadLibrary(String libname) This post will try to explain the differences of these two ways. According to Java Doc on System.load(), it has below description. Loads the native library specified by the filename argument. The filename a...

   NATIVE,JNI,JAVA,SYSTEM.LOAD,SYSTEM.LOADLIBRARY     2019-02-05 05:49:28

  Fix issue where no Java virtual machine found when launching Eclipse

In cases where a new Eclipse is installed or the location of the Java virtual machine binaries has been changed, you may face issue when launching Eclipse. The error would look like. And if you go to the location specified in the error message, there is no such path indeed.  And when clicks OK, the program just exits. The issue here is that it tries to find the java.exe binary and launch the program but it failed to locate it and hence exits. To fix this, you first need to ensure you have...

   ECLIPSE,JAVA,LAUNCH,ECLIPSE.INI     2019-09-07 05:31:27

  Java SynchronizedList and Iterator

While reading some material about concurrency, I come up with some writing about using SynchronizedList wrap about normal List to enable synchronization.   But one interesting thing is http://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#synchronizedList%28java.util.List%29   It says     It is imperative that the user manually synchronize on the returned list when iterating over it:     1   List list = Collections.synchronizedList(new A...

       2015-12-03 03:04:08

  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

  Does mobile application need architecture design?

Looking back to the history of PC software development a dozen years ago there was no  software architecture design, the consequence of this was that there would be a high cost on software maintainability and scalability. Later, people recognized the importance of software architecture and started to make the concept of software architecture mature. Now almost all software will have architecture design which has been the consensus of the software development companies and developers.Simi...

   Software design,Architecture design,Mobile app     2012-04-12 11:14:37

  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

  The concept of Iterative Model in a Software Development Life Cycle (SDLC)

The iterative model implemented in any Software Development Life Cycle is all about an initial, simplified implementation which may or may not gain more complexity in future. Furthermore, it is can even be called as a broader feature set until and unless the final system is accomplished. Now while discussing the model, chances are there that he concept of incremental development will also often be used liberally and interchangeably. This means incremental alterations made during the design and i...

   SOFTWARE DEVELOPMENT,SDLC,ITERATIVE MODEL,SOFTWARE DEVELOPMENT LIFE CYCLE     2017-09-11 06:02:39