I’m learning the super keyword and accidentally get this, here’s an example : The usual way to do this as in the tutorials is super(b) to reusing its parent constructor, but what is wrong with super.a = b? Answer When you write your class A like this: you overwrite the default constructor and in the line this.a = a you
TextView lost after onPause()
I’m learning how to add elements to LayoutParam. I add a TextView element after each click to “`LayoutParam“. my problem is when i press the Home Button and i open the app again, i don’t see any elements. as they have never been. Answer Are you recalling the send() method in the onResume() method? if not then the data you
Collect key values from array to map without duplicates
My app gets some string from web service. It’s look like this: I want to get map from this string: Code: It’s okay and works in most cases, but app can get a string with duplicate keys, like this: App will crash with following uncaught exception: I tried to change collect method: But complier says no: And Array type expected;
Read a file from google storage in dataproc
I’m tring to migrate a scala spark job from hadoop cluster to GCP, I have this snippest of code that read a file and create an ArrayBuffer[String] This code runs in the cluster and gives me 3025000 chars, I tried to run this code in dataproc: it gives 3175025 chars, I think there is whitespaces added to file contents or
Java HotSpot VM Command-Line HeapDumpPath option use hostname for resulting .hprof
Summary: Id like to alter the way .hprofs are named when automatically created to incorporate machine’s hostname + process PID Long version: According to documentation (https://docs.oracle.com/javase/8/docs/technotes/guides/troubleshoot/clopts001.html) you can pass an option to the VM to create heapdumps under certain conditions (HeapDumpOnOutOfMemoryError), and can further customize this behavior by specifying a different path for the resulting .hprof file. You can change
I have an error but dependencies include in gradle root and gradle module config, why?
I have root config gradle.build and have build.gradle in module After download dependencies and add in models annotations like @Entity, @Table @Id and etc. i have an error: cannot find symbol @Entity ^ symbol: class Entity But i have spring-boot-starter-jpa in dependencies, i don’t know why in module i can’t use dependencies. Answer With dependencyManagement you only manage dependencies like
Is there a way to know expire vault client tokens?
I’m using https://www.vaultproject.io/docs/auth/approle.html to generate vault client tokens,but I want to know tokens expire state. Is that possible ? Answer You can get lease_duration and compare it with the current date time. If current date time is after lease_duration, token should be expired. Can you please try?
Spring JPA repository interface and default methods use case
I am currently wondering whether a particular use case could be elegantly addressed by using a default interface method inside a JPA repository. Suppose we have the following entity and supporting types: I need to be able to query a list of SomeEntity based on combination of Status enumeration values. With Spring JPA, its respective repository could look like this:
Casting Issue for Generic Array of Node Objects
I am having problem with java generic array creation where I needed to make an array of type Node. So, I did this for declaration: private Node<E> [] nodes; and later for initialization, nodes = (Node<E>[]) new Node [values.length]; When I try to do something like set the Node object’s attribute value nodes[i].setValue(values[i]); , I get NullPointerException, meaning that there
Create an algorithm that arranges them in order to form the largest possible integer
I am struggling with this coding problem in Java. It has to be solved using an algorithm. It is supposed to give me the largest possible inter that can be formed with the numbers in the array: {10, 7, 76, 415}. I tried to solve it using selection sort. So far I have is this code below but it’s giving