The (very) short answer to your question is that paintComponent is called “when it needs to be.” Sometimes it’s easier to think of the Java Swing GUI system as a “black-box,” where much of the internals are handled without too much visibility. There are a number of factors that determine when a component needs to … Read more
Java’s default heap size (at least last time I researched it) is 128 MB. The latest version of Eclipse (i.e. Helios) is set to run with a default heap size of 512 MB. (see the eclipse.ini file in your Eclipse base path). Therefore, you are probably seeing this behavior because your application needs a heap … Read more
I see no problem with throwing a NPE as early as possible before the JVM does it for you – in particular for null arguments. There seems to be some debate about this, but there are many examples in the Java SE libraries that does exactly this. I cannot see why NPE should be holy … Read more
Do you somewhere have a class or interface named T, or are you using T as a concrete type name somewhere instead of as a type parameter (which means you might have forgotten somewhere else, for example in an enclosing class, to specify that T is a type parameter)? I can reproduce your problem with … Read more
Can somebody tell me what Java DOT operator actually does? For example: public class { int value; public void great() {}; … } public static void main(String[] args) { Person p = new Person(); Person.great(); // <— here Person.value; // <— here I want to know what is . operator doing in above code when … Read more
How do the post increment (i++) and pre increment (++i) operators work in Java?
char digit = (char)(tmp.charAt(i) – ‘0’); In the ascii table, characters from ‘0’ to ‘9’ are contiguous. So, if you know that tmp.charAt(i) will return a character between 0 and 9, then subracting 0 will return the offset from zero, that is, the digit that that character represents.
This is a drive method for two other classes. which i posted here https://codereview.stackexchange.com/questions/33148/book-program-with-arraylist I need some help for the private static ArrayList getAuthors(String authors) method. I am kind a beginner. so please help me finish this drive method. or give me some directions. Instruction some of the elements of the allAuthors array contain asterisks … Read more
I am meant to create a simple insertion sort method which sorts a series of generic names into alphabetical order. This should be simple, and I have already reviewed many other examples of insertion sort online, including on this site, yet I still cannot seem to obtain the correct output despite comparing my code, line-by-line, … Read more
Details of difference between @see and @inheritDoc
