Month: December 2018

Supervision，The literal meaning of supervision is that the parent actor discovers that there is an exception to the child actor, the child actor production policy processing mechanism, if the parent actor does not process, then pass up.  The strategies for post processing of sub Actor exception are: Resume：Immediate recovery Restart：Stop Actor before resuming and recreate it. Stop：Stop it Escalate：Reporting to parent level  SupervisorImplemented by Props. WithChildSupervisor Starategy (), the first parameter of this method is to receive the exception and the Actor’s PID to h...

When developing websites, you often need to send requests to test whether your code is OK or not, and the tools that simulate sending HTTP requests play a big role. In particular, it is necessary to use tools when requesting header. Some of the tools recommended below are based on the system development process.In order, some are based on browser development plug-ins.   Copyright notice: This article is an original article for bloggers. It can not be reproduced without permission from bloggers. Original address: https://www.cnblogs.com/poterliu/p/9563930.html Contact mailbox: poterliu@qq...

meaning of the title It is known that X and y are integers, and satisfy the following two conditions: 1．x，y∈[1…k]，And X, y, K Z 2.（x^2-xy-y^2）^2=1 I’ll give you an integer k, find a set of X and y that satisfy the above conditions, and make the value of x^2+y^2 the largest. k<=1018 An explanation This problem needs to be pushed. (x2-xy-y2)2=1 (y2+xy-x2)2=1 [(x+y)2-xy-2x2)]2=1 [(x+y)2-(x+y)x-x2)]2=1 Then, because the Fibonacci sequence has one property: The way to turn f[n+1] into f[n]+f[n-1] becomes: f[n]2-f[n]f[n-1]-f[n-1]2=(-1)n-1 It is found that these two formulas ...

The way to solve JSP path problem (JSP file start path, basePath function) If you use the “relative path” in JSP, there may be problems. Because of the relative path in web pages, he is looking for resources relative to the address of “URL request”. What does this sentence mean? For example: Suppose we have a project: MyApp Under this project, there is a JSP folder. The folder includes: login.jsp    // Landing page register.jps  // Registration page We enter the address in the browser (Note: content of the address): http://localhost:8080/MyApp/jsp/login.jsp At thi...

1、HTTP Keep-AliveIn the early days of http, each HTTP request required a TPC socket connection to be opened, and the TCP connection was disconnected after one use.The use of keep-alive improves this state by continuing to send multiple data at one TCP connection without disconnecting. By using the keep-alive mechanism, you can reduce the number of TCP connection setups, which also means you can reduce the TIME_WAIT state connectionThen, to improve performance and throughput of the httpd server (fewer TCP connections means fewer system kernel calls, socket accept () and close () calls).Howev...

Definition of factory mode:For the client, hiding object creation logic does not need to use new to generate objects. Implementation mode of factory mode: Create an interface such as Shape; Create specific classes to implement Shape, such as circles, squares and triangles. Create Shape’s Factory, and create different specific classes by Shape type. Finally, the client first creates a Shape factory, and then passes the different shape type parameters to get the concrete class.   Abstract factory definition:Create super factories for other factories; Abstract factory implementatio...

1、cannyoperator CannyThe edge detection operator was developed by John F.Canny in 1986.Multilevel edge detectionAlgorithm. More importantly, Canny created the Computational Theory of edge detection to explain how this technique works. Canny edge detection algorithm in the name of Canny.Word naming is regarded by many as the best edge detection algorithm nowadays. Among them, Canny’s goal is to find an optimal edge detection algorithm, let’s look at the three main evaluation criteria of optimal edge detection: 1.Low error rate: Identify as many actual edges as possible and minimi...