Programming

Apache NiFi Terminology Explained

This article reprints the NiFi terminology list with Chinese explanations.

Apache NiFi Processors List — Descriptions of Each Processor

Apache NiFi has so many Processors that it's hard to know which to use, so I machine-translated them and listed all Apache NiFi Processors to help find which one to use. The document targets Apache NiFi Processors 1.9.0.

Fixing MySQL: Connects via localhost but Not via 127.0.0.1

I ran into this problem while deploying a project at a client's environment. The project's MySQL connection string was localhost, but it errored out saying the database couldn't be connected, and the connection string had been replaced with 127.0.0.1. At first I thought it was a network connectivity issue, so I ran mysql -u root -p and found I could connect fine; ping localhost also resolved to 127.0.0.1. I suspected a mismatched MySQL JDBC driver and swapped countless driver jars, but I was sure it wasn't my program, so I started Googling and found many people with the same situation. I'm summarizing it here for reference. The type of problem I hit was a permissions issue.

Use Lombok to Cleanly and Elegantly Optimize Your Entity/JavaBean Code — A Neat Java Trick

Lombok is a third-party Java library. In projects we often define lots of JavaBeans as entity classes, then use IDE shortcuts to generate getter/setter/toString/equals methods — the code looks huge, and worse, renaming requires batch replacement that can go wrong. Lombok can generate that complex yet low-level code at compile time.

What Are CSRF, XSS, and SQL Injection Attacks, and How to Defend Against Them

Today, for those with no security background, I'll roughly explain how these three types of attacks form. Once you know the principles, you can defend. Since everyone uses different languages and frameworks, this intro focuses on how the attacks form and how to defend — so there's little concrete code; you'll implement it per your own situation.

How to Elegantly Contribute Your Code to Open Source Projects on GitHub

After learning Git, many of you are eager to act — you have opinions on open source projects, or you've found bugs and optimizations. But how do you contribute your code to an open source project? Today I'll show you how to share your code elegantly.

Managing Software Project Versions with Git, plus Git Basics and an Introduction to the GitFlow Workflow

The essence of Git is branch management. If everyone edits on the master branch, the project falls into chaos, so a workflow is needed to ensure normal development — the focus of this article. First, a simple diagram:

Using the MyBatis Pagination Plugin PageHelper for Paged Queries in Spring Boot

This doc uses Spring Boot. For plain Spring you'd also configure the interceptor in the MyBatis config XML. PageHelper is for MyBatis; MyBatis integration isn't covered here, so integrate MyBatis first.

Self-Service Friend Link Application and Automatic Monitoring Are Online; Code Uploaded to GitHub

During the National Day and Mid-Autumn Festival holiday, I suddenly came up with the idea of letting visitors fill in friend-link applications themselves, with the program automatically reviewing them; every day it automatically inspects friend links on a schedule, releasing those that meet the criteria and hiding those that do not.

Things to Watch When Writing SQL — How to Write Efficient SQL Statements