I’m really scratching my heard on this one. I’m new at java, and I’m having the strangest thing happen. It’s homework and I’m taking it one step at a time. My issue is the loop just keeps going and stops asking for input, just keeps looping until it terminates. My comments are la…
Firestore Security Rules: use array_contains to determine authorization
Can I use the equivalent of array_contains in Firebase Security Rules? I have an Event class (corresponding to Event documents in the events collection). Each document has a subscribers list/array that contains the UIDs of all the users who should be able to query for this event: More explicitly, a user shoul…
Order of message receiving with concurrent consumers in Spring and RabbitMQ
I have following code, so I read messages from one queue and resend it, to another one. I am interested in setConcurrentConsumers(3) method does it means that three listener threads will be created? And in such case how I understood order of re-sending to queue1 and queue2 will not be met. As for me is import…
XPathExpression Evaluate returns an empty NodeList in java
I have tried to get value attribute from the tag: My xml is: My method for getting value in Java is: But, my NodeList: nl.getLength() is 0. Could you please help somehow? Thank you in advance. Answer You need to tell your DocumentBuilderFactory to parse namespaces:
How can I check whether data exist in Room database before inserting into database on Android?
In my application I want to use Room Database to show offline data. I wrote below code, but when clicked on button to add in data, if this data exist in the Room database it shows ForceClose error! How can I check for this data in the database, before adding to the database? My NewsOfflineDatum class : My ada…
Doubly Linked List, Insert Before A Given Node in Java
The method not working: Another add method which is working: A print method to debug: DoublyLinkedList class: LinkedList and Node implementations are very straightforward. Find here: https://www.geeksforgeeks.org/doubly-linked-list/ I first create a linkedlist, insert_front() a value to make the head not null…
change binary to decimal
I have to write a method that changes binary to decimal. Write a method that will convert the supplied binary digit (as a string) to a decimal number. convertToDecimal(“01101011”) = 107 convertToDecimal(“00001011”) = 11 i have created it to change decimal to binary however im not sure …
How to get the primary key (PK) of a record in aerospike?
I want to get a specific record from a set in aerospike. But when i execute the following query, i got no result: But when i execute the following query: It gives me all the records, but does not shows the primary key at all. { “edigest”: “BE6ZxLRMKwnbmUqPTvsmcIAgVv8=”, “set̶…
Java Staircase is printing in wrong direction (hackerrank)
This solution to the staircase prints the correct output, but in the opposite direction. Any idea how to alter this solution to get the desired result? Input: Expected output: Actual Output: It’s for a hackerrank easy challenge. I just want to be able to use my approach that I discovered instead of a so…
How to return boolean result from SQL count via JPQL
I have a simple problem with sql query. I need to get true or false, I have tried multiple methods, but without good result. This query returns 0 because I have zero records in database. Perhaps the condition should be adjusted. Thanks for all ideas. Answer Solved, thank you all.