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Why do I need Stream As a highlight of Java 8, stream is similar to Java InputStream and OutputStream in io package are completely different concepts. It is also different from the stream of XML parsing by StAX, nor is it the stream of real-time processing of big data by Amazon Kinesis. Stream in Java 8 is an enhancement of the function of ...

Observer mode of 23 design modes reference material Java design patterns: comprehensive analysis of 23 design patterns (super detailed)Han Shunping's Java design pattern (illustration + framework source code analysis) Qin Xiaobo's Zen of design pattern Please correct any mistakes and omissions below 1, Introduction definition It refer ...

Apache Kafka is an open-source distributed event streaming platform used by thousands of companies for high-performance data pipelines, streaming analytics, data integration, and mission-critical applications. 1 Overview 1.1 basic concepts 1.1.1 Topic By classifying messages through Topic mechanism, we can think that each Topic is a queue ...

SpringSecurity Related concepts Principal [user or device using the system or user logging in remotely from other systems, etc. in short, whoever uses the system is the principal.] Authentication [the authority management system confirms the identity of an entity and allows the entity to enter the system. In short, it means that the &quo ...

1. Introduction 1.1 what is mybatis ● MyBatis is an excellent persistence layer framework ● it supports custom SQL, stored procedures and advanced mapping. ● MyBatis eliminates almost all JDBC code and the work of setting parameters and obtaining result sets. MyBatis can configure and map primitive types, interfaces and Java POJO s (Plain Old ...

1, Array; Copy: system arraycopy(a,1,b,0,4);             int[ ] b = Arrays.copyOf(a,6);Sorting: arrays sort(arr); // Ascending order (from small to large) 2, Method:   Encapsulate a specific business logic functionBe as independent as possible and do only one thing in one wayMethod can be called repeatedlyReducing code duplication is condu ...

Invokebeanfactoryprocessors is a very important method in Spring startup. We need to understand several concepts before parsing the source code of this method. 1, BeanDefinition 1.1. Instantiation of common objects We know that ordinary java files will be compiled into java files when Java runs When we instantiate an object into memory, we u ...

Recursion & iteration recursion Recursion is often used to describe the process of repeating things by self similar method. In mathematics and computer science, it refers to the method of using function itself in function definition. (A calls A) iteration Repeat the activity of the feedback process, and the result of each iteration will ...

Only in cluster mode mongo Can be used changeStream The function of, This function is mainly to monitor in real time mongo Changes to the database, And obtain the changed information, changeStream The principle is to monitor all the time mongo of opLog Log changes to this file, To read this file, as we all know, we have mongo The database will ...

Problem: a classic case of multithreading is the problem of producers and consumers To operate the same resource together is to produce one product and consume another, which must take into account the safe synchronization of threads How to realize thread safety in multithreading and ensure the unity of resources In the producer and consumer p ...