I am trying to implement a printAnimals() method that prints the ArrayList for dogs or prints the ArrayList for monkeys, or prints all animals whose training status is “in service” and whose is Not reserved, depending on the input you enter in the menu. I am trying to correctly write a for loop fo…
Tag: java
java_home is not read by hadoop
I installed java8 with brew install –cask adoptopenjdk/openjdk/adoptopenjdk8 but i think i messed things up, when i type echo $JAVA_HOME it gives /usr/bin/java when i type java -version it gives java version “1.8.0_311” Java(TM) SE Runtime Environment (build 1.8.0_311-b11) Java HotSpot(TM) 6…
Parsing Avro messages in flink , giving null pointer exception if field is nullable in Avro Schema
I need to parse the messages from confluent Kafka stored in Avro. But while applying filter it is giving null pointer exception, without filter i was able to write back into kafka but while applying filter, it is giving null pointer exception. Here is the Schema: Answer When you have null vallue in your topic…
CommandLineRunner overridden run() method not executing
The problem: overridden run() method from CommandLineRunner class is not being executed. Folder structure: Code: Main class: CommandLineRunner class: As it says in the println() method, this is not printing anything, only this startup logs: There are couple existing questions on this topic on Stackoverflow, b…
Make order of responses match order of requests in Netty
Context I am writing a Netty application (Netty 4) in which the processing of each message might take some time. As an example of what I mean I have created an EchoHandler that responds with the original message, though sometimes after a short delay: Problem Using this code, the order of the responses is not …
Bundle is null when starting an activity from a listener using intent
The bundle is null when I use this code. The Logcat shows: MyListenerService.java MainActivity.java I have this working in a similar module of another project and have been comparing them. The only notable difference is that the working MainActivity extends Activity, and this one extends AppCompatActivity. I …
Maven dependency showing up in External Libraries, but errors when used in project
So I’m trying to use a project I made in a different project. I uploaded it to Jitpack and am now using it in my pom.xml like this: This appears to work fine, as the dependency shows up in my External Libraries: Dependency in external libraries As well as in the IntelliJ IDEA autocomplete (Concept is a …
Java – generate and rotate matrix
recently I’m trying to learn Java a bit and currently, I’m working on a simple program that should generate a matrix and then rotate it. I’m stuck at the first part. What exactly is the problem? The logic of my code seems to be fine, but anyway program is returning not what I would expect. T…
peek and element in Java’s LinkedList
What is the difference between peek and element in Java’s LinkedList? Here is what the Oracle Java Documentation page describes them to be, but they do not explain the difference. public E peek() Retrieves, but does not remove, the head (first element) of this list. Specified by: peek in interface Deque…
No runnable method in JUnit test Suites (Initialization error)
I am trying to implement JUnit TestSuites with my 3 Test Classes and run them at the same time. But when ever I run that test suite it gives me error as Initialization Error with “No runnable method found.” This is my test Suite class named as AllTests.java This is JUnitTesting_AddPatientPage.clas…