I have an autowired jpa repository object working. However, I need to use it to add rows into the database from multiple threads. Though, after passing it to another thread, it fails. Code structure However, doing a dbRepository.save() from a thread safe class, I get error cause: java.lang.IllegalStateException: org.springframework.context.annotation.AnnotationConfigApplicationContext@41330d4f has been closed already detailedMessage: Error creating bean with name ‘spring.datasource-org.springframework.boot.autoconfigure.jdbc.DataSourceProperties’:
How to handle empty scanner input strings in java?
I’m working on a .xml file generator. It works by asking the user to input 5 different values and then using them for generating a .xml data container. This is the code: I want the program to detect when someone inputs an empty string by pressing the enter key with no written text and print a message asking the user
Reversing digits in 2D array
I was trying to reverse the numbers in this 2D array, but I happened to be reversing only first and the last numbers. So far I have done this, but don’t know where is the mistake and how to fix it, so that every digits are being reversed, not just first and the last: Answer Ok, here is another way
Why protected constructor can be used to new instance outside of the package?
From gson-2.8.6.jar Outside of the package com.google.gson.reflect, why the protected TypeToken() constructor can be used to new an instance? What’s the grammar that {} appear after new TypeToken<String>()? Answer What you are seeing is the syntax for an anonymous class: https://docs.oracle.com/javase/tutorial/java/javaOO/anonymousclasses.html Essentially what happens is, defines a new anonymous class which inherits from TypeToken. You can immediately derive this from
Mockito returning same argument of ArrayList which is passed
I have a method which is used as : The method mocking followed is as : Option 1 : This is not even working because i think only doReturn needs to be worked, thenAnswer will not work here. Option 2: Getting Runtime exception as : ERROR! java.lang.RuntimeException: org.mockito.exceptions.misusing.WrongTypeOfReturnValue: ReturnsArgumentAt cannot be returned by getPermittedUserIDs() getPermittedUserIDs() should return List If you’re
Kotlin single equal sign “=” object assignment time complexity
What is the time complexity of object assignment using the equals sign in Kotlin (or Java)? More specifically if I have my own object ListNode What would be the copy time below? I find myself often doing this assignment since ListNode passes as val, and I can’t do Answer The assignment does not make a new ListNode object that contains
What is the best practice for using the same create object methods for the test classes
I have 2 unit test classes (ATest and BTest) for 2 classes (A and B). My classes: So 2 classes methods need a User object as a parameter. I have the same method for generating a User in Test classes: getUserForTest method too long. I don’t want it to duplicate. My question is what is the best practice for using
I am trying to make android activity with 3 spinners, and third spinner will display options on based of selection of first and second
I am making an activity with 3 spinners, First spinner only have one value for now but second spinner have total of six values. I want populate 3rd spinner on base of items selected on second spinner (because first spinner only have 1 item). Can any one explain how can I do it? I thought about doing it with switch
Unable to add more than one item in a listview
I am working on a tasks app, for which I created a list view that shows list items consitsting of task names, their priority etc. The data given to the list view is from an sqlite database. I, however, am unable to add more than one item to the list. I have no idea why. I have created a method
Java, Intellij IDEA problem Unrecognized option: –add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED
I have newly installed I cloned project I work with on other workstation without issues, but cannot start any class with main method and IDEA says: I found other comment to check Lombok works and I see it is fine. How to fix the problem? Answer Some configuration were rolled over by the update. How to get back to JDK8