I am a little bit confused about the use of Thread.yield() method in Java, specifically in the example code below. I’ve also read that yield() is ‘used to prevent execution of a thread’. My questions are: I believe the code below result in the same output both when using yield() and when not…
Tag: java
java.lang.Comparable and equals
If I implement java.lang.Comparable for a class, do I still have to override the equals() method? Or will the Comparable work for equals as well? If the answer is no, then what if some discrepancy arises? Let’s say the way I term two objects as equal within the equals() method is different from the way …
Are Locks AutoCloseable?
Are Locks auto-closeable? That is, instead of: Lock someLock = new ReentrantLock(); someLock.lock(); try { // … } finally { someLock.unlock(); } …can I say: try (Lock someLock = new …
Why does the JVM return exit status code 143?
A Java application running as an scheduled task on Windows 2003 crashed with no logs or anything that would help to find out what happened. The only information available, is that the application returned code 143 (8F). That error code was retrieved from the scheduled tasks log. Does anyone knows what that er…
Immutable Type: public final fields vs. getter
I need a small Container-Class for storing some Strings which should be immutable. As String itself is an immutable type, I thought of something like that: Many people seem to object using public fields at all and use Getters instead. IMHO this would be just boilerplate in this case, because String itself is …
How do I use a char as the case in a switch-case?
How do I use a character in a switch-case? I will be getting the first letter of whatever the user inputs. Answer
C++ equivalent to Java this
In Java you can refer to the current object by doing: this.x = x. How do you do this in C++? Assume that each of these code examples are part of a class called Shape. Java: C++: Answer Same word: this Only difference is it is a pointer, so you need to use the -> operator:
AWS S3 Java SDK – Download file help
The code below only works for downloading text files from a bucket in S3. This does not work for an image. Is there an easier way to manage downloads/types using the AWS SDK? The example included in the documentation does not make it apparent. Thanks! Answer Instead of Reader and Writer classes you should be …
An alternative to @Value annotation in static function
It’s not possible to use @Value on a static variable. When I do this, 0 is printed. So what is a good alternative to this? Answer Spring inject noting in static field (by default). So you have two alternatives: (the better one) make the field non static (the ugly hack) add an none static setter which wr…
java.net.ConnectException: Connection refused
I’m trying to implement a TCP connection, everything works fine from the server’s side but when I run the client program (from client computer) I get the following error: I tried changing the socket number in case it was in use but to no avail, does anyone know what is causing this error & how…