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MQTT protocol is widely used in the field of industrial Internet of things because of its low latency and high efficiency. The previous article introduced how to send MQTT message by code. Based on the previous article, this paper implements the subscription and reception of MQTT message.Operation steps: Introduce related dependencies <de ...

1, Create classes and objects Object-oriented programming is a kind of programming method. The landing of this programming method needs to use "class" and "object". Therefore, object-oriented programming is actually the use of "class" and "object". Class is a te ...

Title Description Xiaoyi came to a stone road, each stone from 1 next to the number: 1, 2, 3 This flagstone road can only advance according to special rules: for the flagstone whose number is k, Xiaoyi can only jump forward one divisor step of K (excluding 1 and K) at a time, that is, jump to the posi ...

order This paper mainly studies the variable transfer of reactor asynchronous thread The problem of threadlocal In the traditional request / response synchronization mode, it is very convenient to use threadlocal to pass context variables. It can save adding common variables to each method parameter, such as the current login user. ...

/* Use of interface s 1. Define an interface using the format of interface interface name {}. The primary purpose of an interface is to be implemented by an implementation class.(interface-oriented programming) 2. Interfaces and classes are side-by-side structures in java. 3, Members inside the inte ...

Zipkin service tracking principle Create some tracking identifiers (tracking ID, spanId, parentId), and finally build a request process tree. When each business system calls each other, it will pass specific tracking messages to Zipkin. After Zipkin collects tracking information, it will aggregate, process, store, display, etc. users can easily ...

Recommend a video resource of Gupao College: link: https://pan.baidu.com/s/1SmSzrmfgbm6XgKZO7utKWg Password: e54x First, I will answer the questions that students didn't add in the previous release "be careful when using HashMap". I'd better say how HashMap solves the problem of dead cycle in JDK8. The link list part corresponds to t ...

[TOC] Quick Start for the http Pressure Tool wrk Thank you, teacher cap1537 I've used a lot of manometry tools, but I haven't found the one I like.It feels good to try wrk recently. Write down this guide for yourself to remember, and if it helps you, it's also good. install Wrk supports most UNIX-like systems and does not support windows.Oper ...

The chedulingQueue is a pair of pod storage in the kubernetes scheduler responsible for scheduling. Scheduler uses SchedulingQueue to obtain pods waiting to be scheduled in the current system. This paper mainly discusses the design and implementation of SchedulingQueue, and explores its internal implementation and underlying source code. This ...

In Scala, methods and functions can be almost the same (for example, their definition, use and operation mechanism are the same), but the use of functions is more flexible and diverse. Functional programming is discussed from the perspective of programming mode (normal form). It can be understood as fol ...