The list of the list, but by the output, does not come

I have been trying to insert list of integer to another list but it seems i am making some mistake my output is not coming correct could anyone please help? You can also comment public class ListInsideList { public static void ma

Unexpected Java CharAt type error

I'm doing an assignment that takes two unlimited unassigned integers, represented as strings, and adds them up. My add method is giving me grief. I keep getting this error and don't know why. Here's the part of the code giving me trouble: for(int i =

How to know the lines assigned to Cassandra (CQL)?

There doesn't seem to be any direct way to know affected rows in cassandra for update, and delete statements. For example if I have a query like this: DELETE FROM xyztable WHERE PKEY IN (1,2,3,4,5,6); Now, of course, since I've passed 6 keys, it is o

Using the MySQL PASSWORD () function from hibernation

I'm rewriting old java desktop swing app to JSF application using PrimeFaces. The old app didn't use hibernate but I have decided to use it in new app. Everything works fine but the problem is when I want to save passwords with hibernate using MySql'

Understanding iteration with 2d Java matrices

I am watching a tutorial on 2d arrays and I can't seem to understand where the values for states.length and states[i].length are coming from. How does it know the outer loop deals with the size 3 array and the inner is the size 2 array? public class

Apache Kafka - KafkaStream on topic / sheet music

I am writing Kafka Consumer for high volume high velocity distributed application. I have only one topic but rate incoming messages is very high. Having multiple partition that serve more consumer would be appropriate for this use-case. Best way to c

Inheritance avoiding duplicate member variables

Base Class: public class BaseClass { private Animal animal; public BaseClass(Animal animal) { this.animal = animal; // more code } public Animal getAnimal() { return this.animal; } } Child Class: public class ChildClass extends BaseClass { private Do

Retrieve automatically using Tries

import java.util.ArrayList; public class AutoComplete { boolean newWord = false; ArrayList<String> all = new ArrayList<String>(); static TrieNode root = new TrieNode('!', false, null); void add(String s){ TrieNode temp = root; // TrieNode pare

How to implement the auditor interface in a fragment?

I am trying to communicate between an activity and the fragment that sits on top of it, I want new data (image/text - retrieved from the db) to be passed into the frag every time an onclick occurs (onclick is in the activity). I made a simple interfa

How to do a generic class instantiation and call a method

Right now I have 4 classes which have common method to be called depending on the case as given in below example. Class1 class1 = new Class1(); Class1 class2 = new Class2(); Class1 class3 = new Class3(); Class1 class4 = new Class4(); MyEnum enum = My

@deprecated vs @Deprecated

This question already has an answer here: How to declare or mark a Java method as deprecated? 6 answers I'm able to deprecate a function or class @Deprecated annotation. But a @deprecated entry in XML comment itself marking the class/function as depr

How many java threads can be created for a dual core processor

So the STB is dual core. I thought we can only create 2 proper threads. In every keyreleased() I am creating a new thread Runnable runnable = new Runnable() { int i = j; public void run() { while (true) { System.out.println("This thread is running al

Java: Prefix - Postfix problem

I have a small issue performing a subtraction on numbers using prefix and postfix operators. This is my program: public class postfixprefix { public static void main (String args[]) { int a = 5; int b; b = (a++) - (++a); System.out.println("B = "

Latch that can be incremented

Does anyone know if there is any latch implementation that does the following: has a method to decrement the latch value, or wait if the value is zero has a method for waiting for the latch value to be zero has a method for adding a number to the lat

Outer for loop starts from a certain position

public void removeDups() { int i, k, j, lastFound = 0; if (this.nElements < 1) { System.out.println("Empty Array"); } else { for (i = 0; i < this.nElements; i = lastFound) //outer loop { for (j = i + 1; j < this.nElements; j++) { if (th

How instanceof will work on an interface

instanceof can be used to test if an object is a direct or descended instance of a given class. instanceof can also be used with interfaces even though interfaces can't be instantiated like classes. Can anyone explain how instanceof works?First of al

Volatile: why prevent the code from reorganizing the compiler

In java, with my knowledge, volatile variable make a thread reads/writes directly to main CPU (not in cache of each thread), so make its change visibles to other threads. The thing I don't know is : So, why this work (of volatile) can prevent compile

How to outsource properties of JPA persistence.xml?

I would like to put some of the hibernate configuration in a property file to make it editable without build and deploy. I tried to solve my problem by following the instructions from Create JPA EntityManager without persistence.xml configuration fil

What is the difference between JRE and JVM?

I think the JVM is similar to the .NET Framework, correct? Then what is the JRE? Thank you!The JRE is the environment within which the virtual machine runs. JRE - JAVA Runtime Environment JVM - JAVA Virtual Machine JRE is the container, JVM is the co

Initializing the final variable before the constructor in Java

Is there a solution to use a final variable in a Java constructor? The problem is that if I initialize a final field like: private final String name = "a name"; then I cannot use it in the constructor. Java first runs the constructor and then th