Java
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Combining values with Java 8 streams
If I have a list with integers, is there any way to build another list? If the header difference of the new list is lo…… -
Learning Java, why don’t I get some thread overlap?
I tried the following code: /* package whatever; // don't place package name! */ import java.util.*; import java.lang…… -
Java – use the for loop to move an array of characters
I created a char [] [A,A,B,C] I want to delete the last character, then move the other characters up one and store a n…… -
Parse the CSV file in Java and delete it with a null value
I'm parsing the CSV file into my program, splitting the value into elements, and it works normally unless I have a lin…… -
Java 8 stream adds a new object to the list from the return value
I want to save the return value of the method and use it to create a new object and add it to the list Here is a clear…… -
Java – no data source is configured to run this SQL
I have a problem creating tables (for databases) in Java At present, I am using IntelliJ idea. When I write code to cr…… -
Redundant wording in Java array and ArrayList declarations
A typical ArrayList declaration in Java has the following types: ArrayList<Object> name = new ArrayList<Objec…… -
Parallel programming with threads in Java
Let's say that in Java, using executorservice, I create a 4-thread thread pool and submit it to say 10 tasks, which me…… -
Java – why do programmers say “pass by reference” is actually “pass by value?” Why is this important?
I know in C & amp; The entire concept passed by reference in C. And similar concepts only pass values in Java void…… -
com. sun. mail. smtp. SMTPSendFailedException：530-5.5. 1 requires authentication (java mail)
So I tried to make java mail work, because the other answers I saw on this website were useless. I had to assume that …… -
Set tooltips on all table cells in JavaFX
My application contains a tableview Change the row style by setting a custom cell factory with setcellfactory for this…… -
Java swing error ‘void’ type ‘is not allowed here
See the English answer > "'void 'type not allowed here" error (Java) 6 Code: public void create(JPanel jp){ jp.…… -
How do I provide an implementation for enumeration values in Java?
I have the value of the enumeration class. Assuming that it will grow over time, I hope the user adding the new enumer…… -
Java – why does the clear HashMap method clear the map added in the array list
I'm trying to reuse the same HashMap, such as the following example to populate the list First, I add some values to t…… -
Java – how to use reduce only to find the minimum value in the list?
I want to use reduce only to find the minimum value in list < integer > This is my original idea: List<Intege…… -
Asynchronous – f# asynchronous workflow / task combined with free Monad
I'm trying to build a pipeline for message processing using the free monad pattern. My code looks like this: module Pi…… -
Constructor: final double in Java
I can't understand why the double XX and YY are placed last in the constructor Why don't I double them XX and double Y…… -
Java: triple curl support
I received some comment codes, unlike any code I've encountered before: //{{{ Imports import imports; //}}} Each metho…… -
How does Java 8 add custom elements to a collection?
Is there a Java 8 mode to perform the following operations? for(int i;i<=100;i++){ Person person=new Person(); …… -
Java – if the else statement has four results, but only two seem to work
So I'm studying my first project on programming Never tried any programming I want it to be able to choose between fou…… -
Java – why does changing an object in an ArrayList change it in all other ArrayLists?
I'm making a CPU scheduling simulator (for school projects) There is a problem with my roundrobin function When I do c…… -
Invoking non abstract methods in abstract class java
I have three classes This seems to be a basic problem But I can't find the answer through Google search public abstrac…… -
RX Java – share() and publish() What is the difference between autoconnect()?
In my opinion I thinkhare () and release () Autoconnect () is the same But in this code, the result is different Obser…… -
How do I resize JavaFX images?
I have a JavaFX scene. image. Image, I want to resize it, for example, scale it by a given factor What to do (not conv…… -
A better way to use Java 8
I convert the following code into Java 8 code I wonder if I'm doing it right or if there are other good ways Java 7 fo…… -
java – ！ list. Isempty() and list Size () > 0, same conditions?
I see such code if (!substanceList.isEmpty() && (substanceList.size() > 0)) { substanceText = createAmoun…… -
Java – display integers on toast
I tried to display a toast message with an integer in it Toast.makeText(this,bignum,Toast.LENGTH_LONG).show(); But it …… -
Java – why does kotlin use = = for structural equality and introduce = = = for reference equality
In general, every design decision made by kotlin feels great in itself and provides a good java transition As a java d…… -
Java – can I create a file in my S3 lambda function?
I am creating a Java function for AWS lambda, which imports a file from AWS S3, as shown below: InputStream videoObjec…… -
Java 8 – how do I copy attribute values from one list to another?
I have two lists, for example: List<Foo> list1 = Lists.newArrayList(new Foo(...),...); List<Bar> list2 = L…… -
Java – define new variables
I'm a novice in Java programming. I met something I don't quite understand: if (Object.getSomething() != null) { …… -
Java – how to use recursion to check whether all values in an array are equal?
I try to solve this algorithm recursively; I want to check that all values in the array are the same (or equal to each……