Programming VIP

brief introduction UDT gives you two choices, byte stream or message. Which one do you choose? Experience tells us that only primary school students do multiple-choice questions, and we should all! Definition of type How are the two types of UDT defined? Check out com barchart. UDT package, you can find that these two types are defined ...

Requirements completed in this article: 1. Login takes the form of pop-up layer. 2. Login method: (1) Mobile phone number + mobile phone verification code (2) Wechat scanning (completed later) 3. There is no registration interface. When logging in for the first time, judge whether the system exists according to the mobile phone number. If ...

Exclusive lock Reentrant lock In normal business work, reading and writing are more and less, and reading and writing are separated Read write lock Read thread - > read lock. Read lock is shared. Read lock is not excluded, but write lock is excluded Write thread - > write lock, write lock exclusive, read and write mutually exclusive ...

1. Understanding JWT 1.1. What is JWT? JSON Web Token (JWT) is an open standard( RFC 7519 ), it defines a compact and independent way to securely transfer information between parties as JSON objects. This information can be verified and trusted because it is digitally signed. JWT can sign with a key (using HMAC algorithm) or with RSA o ...

static keyword Variables, methods, code blocks and internal classes used for modification (not involved for the time being). The modified members belong to the class, not just It belongs to an object. In other words, since it belongs to a class, it can be called without creating an object. Class variable When static modifies a member variabl ...

Multithreading 1. Thread overview Process: A process is a running activity of a program on a data set in a computer, It is the basic unit of resource allocation and scheduling in the operating system. A process can be simply understood as a program running in the operating system. Thread: A thread is an execution unit of a ...

on java 8 excerpt (reflection) A basic goal of object-oriented programming is to write code that manipulates only references to the base class (in this case, Shape) The method draw() in the Shape interface can be dynamically bound, so the client programmer can call the specific draw() method through the generalized Shape reference. In all ...

Advanced java (11) -- network programming Portal: ·Zhang Qi MAX· ##Learning objectives Be able to distinguish the characteristics of UDP and TCP protocols Be able to name two common classes under TCP protocol Be able to write string data transmission program under TCP protocol Be able to understand the case of file uploa ...

catalogue thread ThreadPool 7 parameters of thread pool Blocking queue of thread pool Rejection policy of thread pool (RejectedExecutionHandler) Monitor the running status of thread pool Partial source code analysis thread Thread is the smallest unit for scheduling CPU resources. The thread model is divided into KLT model and ULT mo ...

Deep understanding of JVM (2) -- memory structure (2) 4. Pile definition Objects created with the new keyword are placed in heap memory characteristic The safety of all threads in the heap needs to be consideredThere is a garbage collection mechanism Heap memory overflow java.lang.OutofMemoryError : java heap space. Heap memory over ...