Programmer Think

summary Reflection is one of the features of Java programming language. It allows running Java programs to check themselves, or "self-examination", also known as "introspection". Reflection is so powerful that it can even directly manipulate the private properties of the program. We all have a concept in the previous study. ...

TIP This article is included in< Introduction · YuQue >For more in-depth articles, please go to< Introduction · YuQue> . data type There are eight basic data types in the Java language: boolean/1byte/8char/16short/16int/32float/32long/64double/64 The eight basic data types are divided into four categories: ...

encapsulation Example: //student class public class Student { //Property private get/set private String name; private int age; private char sex; //Provide some public get and set methods //get this data public String getName() { return this.name; } //set assigns a value to this property public void setName(String name) { this ...

problem Let's talk about three questions first and look at the source code with questions: How does the thread pool keep the core thread from dying?If the number of core threads is 0, will new tasks be queued first or run directly? Will the process pool eventually die out?Allow the core thread to timeout. Where is the impact point Examples ...

consumer.registerMessageListener(new MessageListenerOrderly() { @Override public ConsumeOrderlyStatus consumeMessage(List<MessageExt> msgs, ConsumeOrderlyContext context) { for (MessageExt msg : msgs) { System.out.println(new String(msg.getBody())+" Thread:"+Thread.currentThread( ...

Inner class: put the definition of one class inside the definition of another class. Advantages: organize some logically related classes together (elegant and clear), and control the visibility of internal classes. 10.1 creating internal classes Put the definition of the class inside the peripheral class public class Parcel1 { class Des ...

Concept of right value reference Book back: C + + implementation of MyString. Continue to use the MyString code here int main() { String s1; s1 = fun(); int a = 10; int& b = a; //int&& c = a; Error!!! Only right values can be referenced int&& c = 10;//Only r-values can be referenced. Numeric constants are pure ...

The use of flask SQLAlchemy encapsulates and optimizes SQLAlchemy: Flask Sqlalchemy is a plug-in of the flask frameworkFlask SQLAlchemy is a plug-in that simply encapsulates SQLAlchemyIt makes it easier for us to use sqlalchemy in Flask. 1. Installation: pip install flask-sqlalchemy 2. Key points of using flask Sqlalchemy: 2.1 database co ...

catalogue 01 abstract class 1.1 examples of abstract application scenarios 1.2 abstract precautions 1.3 practice of abstract class 1.4 anonymous subclasses of abstract classes 1.5 concrete application of abstraction: template method 1.6 practice of abstract class 01 abstract class With the definition of new subclasses in the inherit ...

Function of condition In fact, there are many usage scenarios of condition, which can be used in concurrent scenarios involving condition judgment, such as: Judge whether the queue is full or empty in the ArrayBlockingQueue of the blocking queueBlock and wake up all threads in CyclicBarrierJudgment of blocking access queue data in DelayQueueC ...