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
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
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
This is a mix of the two previous answers:
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
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 {
You need to set the classpath to find your compiled class: java -cp C:\Users\Matt\workspace\HelloWorld2\bin HelloWorld2
Here, Cat.foo() is said to hide Animal.foo(). Hiding does not work like overriding, because static methods are not polymorphic. So the following will happen: Calling static methods on instances rather than classes is a very bad practice, and should never be done. Compare this with instance methods, which are polymorphic and are thus overridden. The … Read more
The most naive way would be to iterate over the String and make sure all the elements are valid digits for the given radix. This is about as efficient as it could possibly get, since you must look at each element at least once. I suppose we could micro-optimize it based on the radix, but … Read more
You have to put file extension here