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Producer principle Producer overview         The party sending the message is called the producer. His role in the entire RocketMQ production and consumption system is shown in the figure:         Producer group: a logical concept. When using producer instances, you need to specify a group name. A ...

Spring has defined org.springframework.cache.Cache and   org.springframework.cache.CacheManager interface to unify different caching technologies; And support the use of   JSR-107   Annotations simplify our development; Provides implementations that support multiple caches. There are two main interfaces: org.springframework. ...

HashMap capacity expansion mechanism Previous review: Talk about HashMap 01 of jdk1.8 Last time we finished the put method, there was a way I did not elaborate, that is resize() method, which I personally think is the most beautiful but the most difficult part of HashMap. Next we will explain it slowly. Review the member variables transient ...

#include <iostream> #include <cstdio> #include <cmath> #include <climits> #include <iomanip> #include <windows.h>// #include <iostream> #define MAX(x,y) (x)>(y)?(x):(y) #include <string.h> using namespace std; class A { public: A() { a=0; co ...

How does ThreadLocal ensure that objects are only accessed by the current thread?Let's dig into the internal implementation of ThreadLocal.Naturally, we need to focus on the set() method and get() method of ThreadLocal.setLet's start with the set() method: /** * Sets the current thread's copy of this thread-local variable * to the ...

1: Introductory case 1: First create a new module = = > set the Java version to 8 = = > find the following components, check and Finish 2: Write the structure as shown in the following figure controller layer UserController class ​ package com.mybatis.mybatis.controller; import com.mybatis.mybatis.entity.User; import com.mybatis ...

Browser access Servlet process: HttpServletResponse object: It inherits from the ServletResponse interface and is specially used to encapsulate HTTP response messages. It defines the method of sending response status code, response message header and response message body to the client. Methods related to sending status codes include: 1. set ...

backgroundSince all services in the company run on Alibaba cloud k8s, and the IP reported to the registry by dubbo provider is Pod IP by default, this means that dubbo services cannot be called in the network environment outside the k8s cluster. If local development needs to access dubbo provider services in k8s, it is necessary to manually exp ...

7, Web component injection 1. Web native component injection (Servlet, Filter, Listener) Method 1: use @ ServletComponentScan + web3.0 annotation Add the ServletComponentScan("") annotation on the main startup class of MainApplicationContext @ServletComponentScan("day01.view") @SpringBootApplication public class MainApplication ...

This article is excerpted from "design patterns should be learned this way"1 UML class diagram of state patternThe UML class diagram of the state pattern is shown in the figure below.2. Use the status mode to realize the free switching of login statusWhen we read articles in the community, if we think the articles are well written, we ...