Java Stream why does reduce requires two parameters of the functional Interface?

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In other words, why does reduce require BinaryOperator, or BiFunction interface? Why doesn’t it use UnaryOperator, or Function interface instead? What is the point of having two parameters as the …

MapReduce filtering to get customers not in order list?

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Currently learning on MapReduce and trying to figure out how to code this into Java. Two input files, called customers.txt and car_orders.txt: customers.txt =================== 12345 Peter 12346 …

Tags: java

Java Hashmap – Please explain how hash maps work

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I am currently preparing for interviews, Java in particular. A common question is to explain hash maps. Every explanation says that in case there is more than a single value per key, the values are …

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java.lang.ClassCastException exception using ObjectInputStream, when sending a class as an object

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https://github.com/IshayKom/RCProject Classes As Shown in the eclipse package manager (I don’t really deal with github so I don’t know how to upload classes correctly) I got an error running my …

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i’m searching for a way to improve this function that’s basically doing the control of double input data type

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this is my Function to control the double input from the user but it control only integer values if the user enter a comma ‘,’ character like for example 100,300 it refuse to accept it so i’m thinking …

How to solve Cannot invoke “String.compareTo(String)” because “[]” is null?

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import java.util.Scanner; public class Search { static Scanner scanner = new Scanner(System.in); static Scanner kb = new Scanner(System.in); static Scanner kb2 = new Scanner(System.in); …

Tags: c++ iterator java

Java Iterator in C++

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I am a Java user and I am getting into C++ and in Java it allows classes to reveal Iterable types so clients can traverse some instance’s collection of data. Is there any way to obtain this …

HTML5 video skips ranges after 32,768

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I am exploring Http Range requests and video streaming with Java. I wanted to create a controller which streams a video to a tag. For some reason, after end range of 32768, the browser sends request …

parallel() not work with the 3-arg iterate()

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Here is my code: int count=20; Stream.iterate(4,i->ii+1).parallel().forEach(i -> { try { Thread.sleep(new Random().nextInt(2000)); } catch (InterruptedException …

Is Android AsyncTask use multithreading because android official web says?

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while learning the difference between multi-threading and Concurrency.i follow this stackoverflow answer according to my understanding AsyncTask is just used to on or off the use of main thread{ui …