[Solved] Abstract Factory Design Pattern for remote file transfer app [closed]

Since you need to adapt to different mechanics\protocols, you can implement Adapter pattern. Also, adapter can be chosen at runtime, you can also implement Factory pattern to instantiate an adapter. And then Strategy pattern to have adapters and factories. All this being done with IoC to inject dependencies like adapters or factories solved Abstract Factory … Read more

[Solved] confusion between && and || in java

&& is a logical and operator || is the logical or operator Using De Morgan, the following: while(!gender.equals(MALE) && !gender.equals(FEMALE)) Can be translated to: while(!(gender.equals(MALE) || gender.equals(FEMALE))) (note the additional parenthesis and the placement of the ! before them). Both the above mean that the gender is neither MALE or FEMALE. Your other code: while(!gender.equals(MALE) … Read more

[Solved] Button not doing anything when it should

What you have <activity android:name=”.ScanResults” /> And when using intent Intent intent = new Intent(MainActivity.this, ScanResult.class); ScanResults and ScanResult are not the same. If Activity is not found you should get ActivityNotFoundException. This exception is thrown when a call to startActivity(Intent) or one of its variants fails because an Activity can not be found to … Read more

[Solved] Explanation for IOException [closed]

The IOException is part of the interface. Errors usally occur when a file is not present, the disk is full, you are missing reading or writing privledges or you have network connectivity issues. Depending on the implementation it might as well throw no errors at all even though its still declared in the interface. 2 … Read more

[Solved] Android – Menu Item Crashing on Click (Camera Intent)

Your error log shows you have SecurityException: Permission Denial…with revoked permission android.permission.CAMERA. This means you are targetting API level 23 and the user has revoked the CAMERA permission. You should add code to check and request permission and handle permission acceptance/denial. Read more about it here. 3 solved Android – Menu Item Crashing on Click … Read more

[Solved] How to search a webpage with keywords from a .txt list? [closed]

Assuming that the .txt file contains one word per line, here is a simple solution: string[] keywords = System.IO.File.ReadAllLines(@”C:\Temp\keywords.txt”); List<string> nomatch = new List<string>(); System.Net.WebClient wc = new System.Net.WebClient(); foreach (string word in keywords) { string response = wc.DownloadString(“http://www.website.com/search.php?word=” + word); if (response != null && response.Contains(“No matches found”)) nomatch.Add(word); } if (nomatch.Count > 0) … Read more

[Solved] Which Solution is better in leetCode in terms of Runtime and Memory Usage? [closed]

“Which is better” is always a matter of opinion. In your particular application, is execution time or memory use more of a problem? Then optimize for that aspect. In terms of leetcode, I understand it’s a sort of quiz, but for numbers that small, my response is “who cares?”. I don’t care about an execution-time … Read more

[Solved] Asking for an integer [closed]

When you’re using Scanner.nextInt() the input is expected to be an integer. Inputting anything else, including a real number, will throw an InputMismatchException. To make sure invalid input doesn’t stop your program, use a try/catch to handle the exception: int num; try { num = sc.nextInt(); // Continue doing things with num } catch (InputMismatchException … Read more