The one of Design Pattern Series, this is factory design for createnal pattern. Please read in the linked document.   Link document:  https:...

youtube tutorial: https://www.youtube.com/watch?v=IEf1KAcK6A8 1 let and scope, 2 const, 3 array function 4 default value 5 Object iteral ext...

 1 Copy Object in java Use = for immutable class ex: Integer , String or Wrapper classes Object   Use Contructor has paramater copy, ObjectA...

JPA find() & getReference() in javax.persistence.EntityManager * find (): always call select from DB   Use for select one entity from DB...

Preface Trong java có 3 kiểu so sánh đặc trưng như sau: + Sử dụng toán tử == : return Boolean Primitive thì so sánh giá trị thực, Reference ...

Persistence Context has two implemnet is JPA EntityManage and Hiberbate Session Example use Session of hiberate  has exist github you can vi...

 1 check Null and Undefined And primative datatype if(object){ // object is not null, undefined, 0, '', false.  but it can empty({})...

  1)  CRUD có thể sử dung find Compositekey hoặc findBy compositeket + column in composite   2) CRUD findBy column And column  3 Not LazyLoa...

This post use language vietnames is, the future is will introduce english version. The clean code for java also application for the others. ...

Parse LocalDateTime to String to pattern  year :                      yyyy || 2021 month of year:       M / MMM / MMMM || 06 / Jun / June da...