Is there anyway to verify the signature of the EU Covid Vaccine QR Code and make sure the QR Code was issued by an authorized entity? Answer Thanks to Gaetano Piazzolla who recently wrote an article on how to verify Green-Pass QR Code Signature. Here is the article link: Green-Pass QR Code Signature Verificat…
Tag: java
MongoDB Aggregation Pipeline – Count no of records that are matching a complex criteria – (Couldn’t find PersistentEntity for type java.lang.Object!)
I have documents with dynamic fields and I would need to find a count of matching records for a given complex query criteria Example Entity Example Data: Expected Query Criteria: Building such complex Criteria using $match would be too much of implementation, so I was trying to use SPEL evolution through $pro…
How can I insert an Item at the end of the List?
I am working on a project for my Data Structures class that asks me to write a class to implement a linked list of ints. Use an inner class for the Node. Include the methods below. Write a tester to enable you to test all of the methods with whatever data you want in any order. I have a method
How to add tiny charts in TableView
I’m relatively new to android and want to know how they add very tiny line charts in table view controls. For example, as shown below: I have tried this so far: implementation ‘com.github.PhilJay:MPAndroidChart:v3.1.0’ But it does not show in LinearLayout Layout without chart: And result wit…
My problem is when I press the clear button, it just clears the textfield and not data of the previous numbers pressed
The task here is to make a Java program that is like a pincode process. I just have a problem with the process of clearing since when I press the clear button, it actually clears the textfield but when I press new numbers, the numbers I typed before even after pressing clear still shows up Please help me with…
How to remove an element and the element after that in an ArrayList if the value of the element is less than a specific integer?
I have this program where I need to remove the value from an ArrayList and the value after that if the value is less than 10. Here is an example: Original ArrayList: [20, 40, 15, 4, 25, 50, 45] Modified ArrayList: (if the value is less than 10) [20, 40, 15, 50, 45] – (Removed 4 and 25 because 4
Unicode normalization forms Explanation (Java)
I’m using Normalizer.normalize(url, Normalizer.Form.NFD) to avoid having characters like é in my url, and I do not understand the meaning of the Normalizer.Form consts (NFC, NFD, NFKC, and NFKD) or when to use each one. I consulted the documentation but this did not help at all. Does anyone have any ide…
best way to store aes encrypted data
What is the best/secure/easy to implement way to (locally) store data which has been encrypted using AES encryption? There doesn’t seem to be a proper guide or standard way to store the data, but after looking at some projects that use AES encryption, these seem to be the formats that come most: XML Tex…
Process List with synchronous delay after flatMap?
Hey I just started to dive into reactive programming and I can’t figure out how to process a List<String> in a synchronous way after flatMap. What I am trying to achieve: Get domain list from external service Filter out existing domains in database Make another http request to external service to …
How to parse Java code in Python using ANTLRv4
I’m trying to parse some Java code in Python using ANTLRv4. I’ve tried to follow this post, but I get the following error: I can’t figure out what I’m doing wrong. The file I’m trying to parse is proper Java, it’s extracted from the docker-maven-plugin package. I’ve t…