Graph of Data Structure

Graph of Data Structure 1. introduction Graph structure is also a kind of non-linear data structure. There are many examples of graph structure in life, such as communication network, traffic network, interpersonal network and so on, which can be reduced to graph structure. Each node of the graph structure can be related to each ot ...

Added by simn_stv on Fri, 17 May 2019 14:35:30 +0300

Error Handling Scheme for RxJava2

Recently, retrofit2 + rxKotlin2 was used to write interface access, trying to smoothen the code as much as possible, so when the status code returned by excuse is "unsuccessful" (e.g. code!= 200), it is unified in the onError method with network errors. The idea is always good, but in practice, onError failed to catch exceptions, res ...

Added by hush on Fri, 17 May 2019 11:39:34 +0300

Building IKEv2 VPN on strongswan in Aliyun CentOS 7

1. Install Strngswan yum install strongswan systemctl enable strongswan systemctl start strongswan 2. Creating Certificates strongswan pki --gen --outform pem > ca.key.pem strongswan pki --self --in ca.key.pem --dn "C=CN, O=iSoft, CN=iSoft wendell CA" --ca --lifetime 3650 --outform pem > ca.cert.pem strong ...

Added by Miri4413 on Fri, 17 May 2019 00:50:07 +0300

Arduino for True Internet of Things - Remote Communication via MQTT Server - Two Boards

What I do on the remote interaction between the board and the board when I'm doing a competition The things found in Baidu are also fragmented. At the same time, I hope my blog can give you a little help PS. This is also my first time to write inappropriate blog terms. I also hope you will understand and point out Dead work R ...

Added by Andy17 on Thu, 16 May 2019 20:14:44 +0300

Basic Concept Interpretation of OkHttp

Recently, in sorting out Android commonly used third-party framework related things, said that Android framework, nothing more than Android development in the common network, image caching, data interaction, optimization, page framework, among which the network as a basic part, I believe that you are more using OkHttp, and in t ...

Added by PHPcadet on Thu, 16 May 2019 18:27:16 +0300

Python exceptions and files in the Python Learning Manual

In the last article, we introduced Python's functions and modules, and now we introduce exceptions and files in Python. To view the previous article, please click: https://www.cnblogs.com/dustman/p/9963920.html Exceptions and documents abnormal Exceptions are also called exceptions. You've seen exceptions in previous articles. When program runn ...

Added by melittle on Thu, 16 May 2019 13:10:13 +0300

Upload image files and parameters using OkHttp (both front and back codes)

I've written a code about using Retrofit to upload picture files, but what if OkHttp is used? I believe that some of the students who know about the two know that in fact the implementation of Retrofit's internal network request is OkHttp. After wrapping one layer, it is just for the convenience of developers to write interfaces an ...

Added by poe on Thu, 16 May 2019 07:58:36 +0300

s21day30 python notes

I. Content Review and Supplement Brief description of three handshakes and four waves The three handshake accept accepts connections waiting for clients in the process connect client initiates a syn link request If you get the server-side response ack, you will also receive a syc link request from the server-side. After the client responds ...

Added by sherrilljjj on Thu, 16 May 2019 04:42:17 +0300

Redis Distributed Lock--PHP

The Role of Redis Distributed Locks In a stand-alone environment, there is a second-kill commodity activity, in a short time, server pressure and traffic will rise sharply. This will lead to concurrency problems. If you want to solve concurrency, you need to solve it. 1. Improving system throughput, that is, requests processed by qps per second ...

Added by Drebin on Thu, 16 May 2019 01:18:22 +0300

Algorithmic Basis - Time Complexity, Three Ordering Algorithms of Conventional O(N) (Bubble, Selection, Insertion)

This article is only my own notes, and does not have any guiding significance. The original intention of the code is to make it easy to understand. There are many codes optimized by God on the Internet. It is not recommended to copy the code in this article in the project. Catalog Time complexity Operation of Constant ...

Added by bugz-2849 on Wed, 15 May 2019 23:10:28 +0300