Recent Posts
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Install Ubuntu in the virtual machine
12. After the installation is completed, click "restart now" in the pop-up dialog box; 13. Prompt to remove the instal…… -
Multithreading — concurrency
Three of them (iterators, generators and decorators) are important parts of Python's high-level syntax! -
Java different time format conversion
Date --> String You can specify the corresponding pattern during conversion. -
STL – STL summary
6、 Deque ·#Include < deque > · double ended queue· Common interfaces: front(), back(); push_ back(),push_ front…… -
Java – ApplicationContext cannot be loaded when running spring launch integration test
I'm trying to write integration tests for spring boot I hope the server should start during the test so that I can con…… -
Java – use the stream API to create an object initialization loop
I have a set of constant values that can be used as a list Using these values, I must create a key - value pair object…… -
Java – what’s the difference between formatting integers as% D and% s?
Although both are grammatically valid, the following important potential differences should be noted: String result = …… -
There was a problem using Jackson to use JSON serialization in Java
Good morning, man! I have a JSON string that looks like: { "StatusCode":0,"Message":null,"ExecutionTime":0,"Respons…… -
Differences between Java 6 and Java 7 in ArrayList capacity growth
I have a question about how to manage the capacity growth (not size, but capacity) of ArrayList in Java At this time, …… -
How to assign incremental values to lists in Java 8
Suppose you have a list of objects The list is sorted by one or more fields of the object So according to the sort lis…… -
Java – convert the 3D world (arcore anchor / pose) to the corresponding 2D screen coordinates
I am trying to achieve this transformation Given the anchor pose in arcore, how can the corresponding 2D coordinates b…… -
Java – does referencing array indexes cause memory leaks?
I'm reading "item 6: eliminating obsolete object references" in the second edition of effective Java The following is …… -
How do I convert numbers from double to int without rounding?
I want to calculate how many columns can fit in the container First, I calculate how many columns can fit, and then ca…… -
Java – how to short circuit when calculating duplicate values between two lists?
I have 2 lists. I need to calculate / check the duplicate elements in list a that match the elements in List B in the …… -
Java recursion does not iterate over all top-level elements
I face the problem of recursion I have an object that contains its own list. Each object in the list can save its own …… -
Java – warning: unclosed file of type ‘[io. Realm. Orderlistrealmproxy]’; These types are not annotated
What is wrong?! Solution This is because you are using list < > instead of realmlist < > you extend realmo…… -
Ui5 – technical part – signature board
2.Javascript 1 jQuery(function() { 2 sap.ui.core.Control.extend(‘SignaturePad‘,{ 3 Metadata: { 4 …… -
Java – the value passed by the unit test to the static method
Example code: class MyClass { public void myMethod(Request request) { Item item = getItem(); ItemU…… -
Java – spring sleuth and Zipkin: artifact IO not found zipkin. brave：brave-bom：pom：4.16. 3-SNAPSHOT
I have a spring boot 2.0 0 rest service, I tried to ask sleuth and Zipkin to send the trace to my localhost Zipkin ser…… -
Why does the Java stack trace only return failures in the finally block?
I have written some automated tests, and the syntax i use is as follows – try { // Test case steps and validations…… -
Java – sort elements by field
I have a set of objects from the same class, and each object has an enum field, which is comparable Collections.sort(A…… -
What is the difference between selenium standalone server and Java selenium jar files
This may sound like a stupid question, but I want to know the difference between selenium stand-alone server and Java …… -
Lambda – grouping and summing list items using java 8 streams
Suppose I have a list < banana > banana Banana class is defined as follows: Banana. java public class Banana{ …… -
Java – why doesn’t the Oracle specification tell you anything about meta spaces?
As we all know, Java 1.8 permgen was deleted and replaced by Metaspace I've read a lot about Metaspace, and I'm sure i…… -
Java – is it more efficient to scan an array once for multiple predicates or multiple times for a single predicate
I have an int array of 1000 elements I need to extract the sizes of various subgroups in the array (how many are even,…… -
Design pattern course design pattern intensive lecture 7-3 source code analysis of builder pattern (JDK + guava + Spring + mybaties)
StringBuilder public synchronized StringBuffer append(Object obj) { super.append(String.valueOf(obj)); return this…… -
Java – cannot use paths Get() loads files from Maven resources
I apologize for this seemingly simple and almost stupid problem, but I spent a lot of time fixing it without much succ…… -
Java 9’s new docs structure – where are the “old” Java packages?
I'm used to accessing Java se documents from the following links, where I can search for Java awt,java. Util and other…… -
PAT A1001-A1004
A1002 ： A+B for Polynomials (25 point(s)) The key to solving this problem is the condition given by the problem: the …… -
java – Guice Bind Generic Types
Is there any way to bind the generic type of the following type: public interface A<T extends Number> { void p…… -
How to properly close JavaFX alerts / filechooser, etc
I am looking at this problem JavaFX show dialogue after thread task is completed, but my problem is just the opposite …… -
Dplyr: select all variables except those contained in the vector
This should be a simple question, but I'm trying I have a variable name vector that I want to exclude from the data fr……