Programmer Think

1. JAVA overview Java 8 (also known as jdk 1.8) is a major version of Java language development.Java 8 was released by oracle in March 2014 and can be regarded as the most revolutionary version since Java 5. Java 8 brings a lot of new features to the Java language, compiler, class library, development tools and JVM. 2. Benefits of new fe ...

When we use JDBC to access the database, in addition to writing our own SQL, we must also operate connection, statement and resultset, which are actually auxiliary classes. Not only that, accessing different tables, but also writing a lot of the same code, which is cumbersome and boring. After using Mybatis, you only need to provide your own SQ ...

if statement Format 1: if(Relational expression){ Statement body; } Execution process: 1. First calculate the value of the relationship expression 2. Execute the statement body if the value of the relationship expression is true 3. If the value of the relationship expression is false, the statement body will not be executed 4. Continu ...

The project is advanced to build a safe and efficient enterprise service Spring Security The bottom layer of Spring Security intercepts the whole request by using filter (many special login, permission, exit...) and Java EE specification. The control of permission is relatively advanced. If the permission is not available, you can't get to ...

catalogue Write in front I. what is a JdbcTemplate? 2, JdbcTemplate framework construction 1. Import the required jar package 2. Configuring JDBC data sources (1) . configure data sources directly in (2) . import external configuration file 3. Configure the JdbcTemplate object 3, Detailed explanation of persistence layer operation 1. ...

Single column collection ArrayList Variable array, default capacity 10. Automatically move the following elements after inserting them Not thread safe Vector The main difference from ArrayList is that the thread of Vector is safe, and other usage methods are consistent with ArrayList LinkedList The bottom layer is realized by two-way lin ...

Day8 java exception concept Exception: in the Java language, abnormal conditions during program execution are called "exceptions" Exceptions (all abnormal conditions at runtime) that occur during the execution of Java programs can be divided into There are two types: Error: serious problems that cannot be solved by the Java vi ...

At present, most company project frameworks basically belong to the front-end and back-end separation mode. This mode will involve a front-end and back-end docking problem. It is very necessary to maintain a complete and standardized interface for front-end or back-end services, which can not only improve the docking efficiency, but also make m ...

I Mail protocol: Sending and receiving mail has the same mail transmission protocol as HTTP protocol SMTP: (Simple Mail Transfer Protocol) POP3: (Post Office Protocol Version 3) mail receiving protocol IMAP: (Internet Message Access Protocol) II Mail sending and receiving diagram 1. Send mail to the same mail server (163 mailbox example): ...

From the overall logic of the JVM in the previous article, this article will talk about the class loading mechanism Review some working models: one we wrote ourselves java file, compiled and generated Class file, will The class file is loaded into the JVM according to The different data information of the class binary file is allocated to ...