masterclass | MasterClass Clone | Web Services library

I've been following Tim Buchalka's course Java Programming Masterclass for Software Developers and I've been modifying his program from lesson 118.

I want to update my list at the runtime while using the list iterator (navigate method). The program runs fine, but if I update my list, Java throws an error: ConcurrentModificationException

I have come up with the following solution: Whenever a user performs a modification of the list, other methods run, and update the list and pass it to the navigate() method. By doing this, my program enters multi-level nested methods, and the problem comes up when a user wants to exit from the program (case 0: in navigate() method). User has to press 0 as many times as many nested methods were ran.

My initial idea was to count how many times navigate() was nested, then using for loop return as many times as it was nested. But later I understood it does not make sense

What can I do to exit from the program by using case 0: just once?

I am trying to make a simple api call using Python to Azure DevOps to get list of users. URL is providing results via browser but getting error while scripting as below. I need to further proceed with the json response. Can some one help please? Python version: 3.8.3

Script

I am new to JS and I got the below code from one of the internet forums and it's not working if I invoke the function from the Javascript class like below. When I try to execute I get the below errors and I am unable to figure out whats the reason. Can someone please help me with what I am missing here?

I have a pre-existing condition so I am trying to find a vaccine, many of the websites say "check back for updates" this checks for changes in the site hash and sends an email when a change is detected. I found an old python 2 script that checked for a change in a site, it would print that to the console, so I adapted it to Python 3 (successfully!) and added code to send an email (successfully!) but now I want it to do the whole thing to a list of URLs, and I am struggling (this is the first real piece of code I have ever worked on, I'm halfway through the Udemy Python Masterclass).

I want it to iterate through a list of URLs with a for loop, put all of the url hashs into a list, then wait 60 seconds, do it again, and compare the 2 lists, if one of the sites has a change, I want that URL emailed to me. I know I am close but I would truly appreciate some help <3 I think it all works except for the code around the 2 #TODO comments.

I am trying to find and remove an element from my ArrayList list (made from a custom master class ShoppingBasket) based on a user inputted String itemSearch whereby they would enter say Apple if they wanted to remove that from the basket, regardless of if the quantity is higher than 1.

The project is setup so that I have a masterclass ShoppingCart, with several subclasses Fruit, Dairy. Each class has a itemName and itemQuantity attribute.

Here is my Fruit class:

All,

I'm building a media player using Amazon Corretto 11 library and OpenJFX. I have this issue that's keeping me on the struggle. Still a newbie in Java, it will be much appreciated if someone can help me out on this.

...

Overview: I have a GUI-based program that has a multitude of functionality built into buttons and menu selection items. Many of the processes are instantaneous, but several of them can easily take more than 5, 10 or even 20 seconds.

Current Problem: While I have a dialog box displaying, it will not display the text inside of the box, such as 'Completing Process, please wait...'

Goal: While a long processes run, I would like to display a 'please wait' dialog box, so that the user knows the program is not stalled and is working on the function the user selected.

Background info: The GUI is built in PySide2 (aka PyQt5) and Python 3.6.5

Current Attempts:

Method 1 - Initially, I used the threading module to initiate the primary function to be run. At the start of the function, I would have a call to show the dialog box, which would display as intended and the rest of the function would process/complete in the background.

Method 1 Problem - This worked great until the program became more complex and I needed to use ThreadPoolExecutor to speed up things. ThreadPoolExecutor and the threading module do not work well, if at all together and will result in a crash without an error message, so I had to abandon that method.

Method 2 - I tried using the setModal function of the QDialog box and called the exec_ function

Method 2 Problem - The dialog box would show and display the text as desired, but setModal(False) had no effect and the processes would be halted until the window was closed.

Method 3 (current method used) - In the initialization of my ProcessRunning dialog window class, I have created a PySide2 signal, which takes in a string (the string being the message that I want to display). The preceeding line before a call to a long process, I called the emit() function of my signal, connected to which is the function to display the dialog box.

Method 3 Problem - The window displays and the background process runs but the window doesn't display the text, almost like that part of the process is held up by the background process.

Summary: While the question title suggests I don't know how to display a QDialog box, the real problem is displaying the text inside the window which instructs the user to "wait." I feel that since this isn't happening with my current method, I am not displaying the box "correctly". So, the "correct" method to achieve this is what I am in search of.

Here's a "short" example using concepts I have in my full program. :

I have a graphic example so you understand what I mean:

MasterClass wants to use class A, B and C, but B is inside A, and C is inside B. So the two ways that I know how to solve this problem are these:

1.Class B will have methods that will call directly into Class C methods, and class A will have methods that will call B methods (including C Methods) as the image:

2.On Solution two every class has a getter what will return the class that they are usign so the other classes can call their methods directly, I mean, if MasterClass wants to use methods on C, it will call method getClassB() from Class A and then call the method getClassC():

Sadly I end up always on situations like this, so I dont know if it is a very commun situation when designing or it is just that i dont know how to design. In the last case, I will be gratefull if you can recommend me material so I can learn How to create clean and modular programs since a lot of my programms end up with a lot of classes interconecting.