Some common websites

processon

Mapping website processon – It can be used to draw pictures , It's comprehensive , Like the flow chart , Class diagram , Use case diagram , Sequence diagram ,E-R You can draw pictures or anything
processon

---

Java On-line API

You can check Java Of API, Yes JDK It's the same thing
Java On-line API

---

Maven

Maven – You need to import jar Packages or frameworks can be found here
Maven

---

Git

Git – Don't mention this , The above knowledge has not been learned , Strange open source projects are just a bunch of them ...[ Over your face ]
Git Official website

---

Code cloud

Code cloud – Follow Git similar

Gitee Official website

---

Mybatis

Mybatis – See the official development manual
Mybatis Official website

---

Spring

Spring Official website – It is a good place to learn English , But if you want to follow the technical route , It is essential to read the official website manual ....
Spring Official website

---

poi Official documents

poi What is it? , I won't go into that here
poi Official documents

---

C# Official documents of

For me C# Chicken with vegetables is very useful
C# Official documents