I am new to Java generics and have managed to get a getKeyByValue function working with a HashMap, but I don’t understand how the function declaration can be ambiguous/redundant …
Make sure to call FirebaseApp.initializeApp(Context) first.Default FirebaseApp is not initialized in this process
I am facing this issue and seen some answers on this site but did not get any proper solution. I have used previous version of Firebase which works fine but when I try to upgrade using Upgradation and update Firebase class to DatabaseReference it shows error and not working. Error Screenshot My Module app is given below: and Project gradle
Spring Boot, using oracle-ldap url through ssh tunnel on local machine
There are 3 machines: local -> some remote server -> oracle db server (via ldap) I want to set up datasource connection (in my spring boot app) to the oracle db. There is no direct connectivity between local machine and the one with oracle db. So, i’m using the ssh tunnel through remote server: ssh -L 127.0.0.1:8081:some.ldap.host:389 user@remote.server.host In application.yml
How to downgrade JDK?
Currently my Java version is 17. Neo4j requires me to install Java 11 or OpenJDK 11, or else it will give the error java.lang.IllegalAccessException: module java.base does not open java.nio to unnamed module @1817d444. I guess I need to downgrade to JDK 11. Java Platform, Standard Edition 11 Reference Implementations is the only place I can get JDK 11. However
JPA repository return one item from db but there are multiple item in the db
I have the following function in my repository When I use this function in the controller I got back one User. For example, if I have a String “John” and I call the repo function with that string I got back “John Doe” but I also have “John Doe Jr” in the db and I need him too. Why I
endpoint for authentication with spring security
I wanna create custom endpoint for login. It works fine when password and username are correct but returns 200 and login form instead 401 for incorrect data. public class SecurityConfiguration extends WebSecurityConfigurerAdapter { private final UserDetailsService userDetailsService; } Answer Try something like that: Don’t forget to Autowire AuthenticationManager and other services!
Java mutable object to causing nullpointer exception
I have the following DTO and I pass the objects to the ArrayLists to prevent objects to be changed and fix the SonarQube error as “Message: Store a copy of allergenInfoList”, etc. However, this approach requires null check and it makes my code ugly as shown below: So, is there any better approach to fix the problem without null check?
Java Swing Application Window – Second Form showing empty
The first class or JFrame that displays just fine And now my second class.. I’m sorry I’m a complete noob, when I run the debugger it looks like Options Menu is constructing correctly, but then it just displays as the minimize, full screen and exit button and nothing else. It will also run perfectly fine independently if I run it
Making a binary tree with a constructor with an array parameter
I’m currently trying to make my own binary tree by using a constructor with an array of objects as a parameter. I want it to go depth-by-depth, and going left-to-right in each level. I currently have …
Serialize objects to a map with the object class as the key?
I’m writing a application using Spring boot and jackson for JSON parsing. I need to handle another service which produces JSON like this: { “task-id”: 5081, “task-created-on”: {…