Programmer Think

import java.util.concurrent.Callable; /** @description: create a computing task class, implement the Callable interface, and rewrite the call method @author: xz @create: 2021-06-02 22:06 */ public class ComputeTask implements Callable { private String taskName;//Task name //Task constructor public ComputeTask(String taskName) { ...

Class object and reflection mechanism. After understanding the concept of reflection mechanism, it can be seen that if you want to use java reflection mechanism to do something, you need to use Class object, so Class object is the premise of reflection. So, how to get the Class object? There are three ways to obtain Class objects in java: ...

Summary: HashMap adopts the chain address method. When there is a conflict, it will be transformed into a linked list. When the linked list is too long, it will be transformed into a red black tree to improve efficiency. HashMap limits red and black trees so that red and black trees can only withstand pressure in a few extreme cas ...

js runs inside the js engine in the browser's kernel Node.js is a JavaScript program that runs out of the browser environment and is based on the V8 engine (Chrome's JavaScript engine) 3. Server side application development (understand) Create 02 server app js const http = require('http'); http.createServer(function (request, response) { ...

However, in MySQL, there is no keyword rowNum. If my table does not have a self incremented primary key id, or the primary key I use is an unordered UUID. And I have a requirement: how to delete the data in rows 6 to 10? In daily development, I wonder if you have ever encountered a time when the query condition is "line"? In fact, th ...

AQS Reentrant lock When the thread that has successfully acquired the lock obtains the lock again, it can be count + +. As long as count > 0 means that the lock is held by the thread, release the lock every time count - until count=0 means that the thread no longer holds the lock; Reentrant lock can effectively avoid deadlock of a single t ...

for (TreeNode<K,V> x = b, next; x != null; x = next) { next = (TreeNode<K,V>)x.next; //The next value of the incoming node is assigned to the next node of the current treebin node, which is used for data synchronization x.left = x.right = null; //null both the left subtree and the right subtree if (r == null) { ...

</resource-ref> ## Write jsp Because you need to web Use in environment, if you write directly from a class main Method testing, will always be wrong, currently there is no good way. It's easy to use here jsp Take a test. <% String jndiName = "java:comp/env/jdbc/druid-test"; InitialContext ic = new InitialContext(); // Get ...

After using static import, you can omit the class name to access static members (member variables, methods, nested classes) Classic usage scenarios for static import: import static java.lang.Math.PI; public class Main { public static void main(String[] args) { System.out.println(2 * PI * 10); System.out.println(2 * PI * 20); } ...

If you understand the above, you can understand the most basic configuration of Zuul. See below. server: port: 9000 eureka: client: service-url: # Just register Eureka here defaultZone: http://localhost:9997/eureka Then add the @ EnableZuulProxy annotation to the startup class. Yes, it's that simple. 2) Uniform prefix This ...