Fill an array with random numbers [duplicate]

You need to add logic to assign random values to double[] array using randomFill method. Change To Then you can call methods, including list() and print() in main method to generate random double values and print the double[] array in console. One result is as follows:

java IO Exception: Stream Closed

You’re calling writer.close(); after you’ve done writing to it. Once a stream is closed, it can not be written to again. Usually, the way I go about implementing this is by moving the close out of the write to method. And add a method cleanUp to close the stream. This means that you have the … Read more

Best way to represent a fraction in Java?

It just so happens that I wrote a BigFraction class not too long ago, for Project Euler problems. It keeps a BigInteger numerator and denominator, so it’ll never overflow. But it’ll be a tad slow for a lot of operations that you know will never overflow.. anyway, use it if you want it. I’ve been dying … Read more

Address already in use: JVM_Bind java

Address already in use: JVM_Bind means that some other application is already listening on the port your current application is trying to bind. what you need to do is, either change the port for your current application or better; just find out the already running application and kill it. on Linux you can find the … Read more

What does idempotent method mean and what are the side effects in case of calling close method of java.lang.AutoCloseable?

Idempotent means that you can apply the operation a number of times, but the resulting state of one call will be indistinguishable from the resulting state of multiple calls. In short, it is safe to call the method multiple times. Effectively the second and third (and so on) calls will have no visible effect on … Read more

Must issue a STARTTLS command first

You are probably attempting to use Gmail’s servers on port 25 to deliver mail to a third party over an unauthenticated connection. Gmail doesn’t let you do this, because then anybody could use Gmail’s servers to send mail to anybody else. This is called an open relay and was a common enabler of spam in the early days. Open … Read more

Java: How To Call Non Static Method From Main Method?

You simply need to create an instance of ReportHandler: The important point of instance methods is that they’re meant to be specific to a particular instance of the class… so you’ll need to create an instance first. That way the instance will have access to the right connection and prepared statement in your case. Just calling ReportHandler.executeBatchInsert, there … Read more

Error: class X is public should be declared in a file named X.java

Name of public class must match the name of .java file in which it is placed (like public class Foo{} must be placed in Foo.java file). So either: rename your file from Main.java to WeatherArray.java rename the class from public class WeatherArray { to public class Main {

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)