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.
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1.Install additional software sources EPEL and nux-dextop
rpm -Uvh http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm
rpm -Uvh http://ftp.sjtu.edu.cn/fedora/epel//RPM-GPG-KEY-EPEL-7
2.Install required files
yum -y --enablerepo=nux-dextop install gstreamer-ffmpeg vlc gstreamer-plugins-ugly gstreamer-plugins-bad gstreamer-plugins-ugly ffmpeg libvdpau mpg123 mplayer mplayer-gui gstreamer-plugins-bad-nonfree gstreamer1-libav gstreamer1-plugins-bad-freeworld gstreamer1-plugins-ugly
ps:Some of them may be installed when the system is installed, and the ins...
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...