Preface Khái niệm   Oauth và ApIs Scope and consent (phạm vi và sự đồng ý) Oauth Actor Oauth Tokens   Front Back Channel Giả Xác thực Với Oa...

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({})...

Knowledge of collection in java Interface Iterator interface Collection interface List Interface    Queue Interface    Deque Interface    Se...

For immutableuse equallist we simple use list.equal list it return true if content same. (compare index)  //case true  List<Integer> l...

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...

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

 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 ...