void run() {
...
if (done) return cancel();
...
}
where cancel() return void. This won't compile... and I can almost understand why. But if I want to return a void from a void, why not? Instead, I end up writing something like this:
if (done) {
cancel();
return;
}
I'm not looking for code style suggestions, I want to know why Java expressly prohibits this type of void r...
Is null an Object in Java?
There is a Java Void -- uppercase V-- reference type. The only situation I have ever seen it used is to parameterize Callables
final Callable<Void> callable = new Callable<Void>() {
public Void call() {
foobar();
return null;
}
};
Are there any other uses for the Java Void reference type? Can it ever be assigned an...
I can't answer completely "why should we call "void" is 'return type'?"
How do I prove that "void" is a type?
:: in JAVA
I realize this issue is somewhat trivial, but I'm interested in knowing the "correct" answer.
I'm trying to extend android.os.AsyncTask<Params, Progress, Result>,
but my task doesn't require any parameters.
Given that I have to overload protected Result doInBackground(Params... params),
what is the "best" way to pass in no parameters?
Currently, I'm using Object as the Params type and...
Sorry for the title :-/
I wrote a parser for a calculator. It works, but I don't like my token hierarchy. The parser should be unaware of the concrete number type, e.g. it should be configurable for Double, BigDecimal etc. So I have a generic token interface
public interface Token<T> { }
public class NumToken<T> {
private final value T;
...
}
public class OperatorToken<T...
Trying to write a UDP client-server application using Swing. Each instance of the client should be able to send messages to the Server (from the event dispatch thread) and also continuously listen for messages from other clients relayed through the server (on a worker thread using SwingWorker). I'm trying to implement a ListenWorker class now whose doInBackground method will continuously listen...
Here is the code,
class Car
{
public static String owner;
public static String car;
public static Integer plate_num;
public static String car_color;
Car(String owner, String car_name, Integer num, String color)
{
owner = owner;
car = car_name;
plate_num = num;
car_color = color;
}
Void display ()
{
System.out.println...
My Java app uses a java.util.concurrent.Executors.newCachedThreadPool() to launch a number of different threads that do different kinds of work.
Some of the threads return a value. For these, I am using Future.get() to retrieve the value from the thread.
Other threads don't return a value that I care about. They are declared to return an Object, and the returned value is always null. For t...
