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Write log output environment configuration file During the development process, the most important thing is to view the log information output by the program on the console. Here, we choose to use log4j tool to output: I Preparations: import the jar packages beginning with log4j in [lib] under [MyBatis] folder into the project and add dependen ...

Why should we learn maven? Before maven was born, we had a lot of inconvenience in making the project. 1: jar packages are hard to find 2: jar package dependency 3: Jars are inconvenient to manage (manage jar s according to different functions) 4: Project compilation Introduction to Maven Maven is an open source project o ...

1. Foreword Requirements encountered in recent work: it is required to make a desktop application, which is used to connect the Linux system and has operation and maintenance function. It is required to run win and operate through the interface, but the interface is not required to be very beautiful. Since I mainly focus on Java and am relati ...

Integration of Log in SpringBoot 1, Classification of logs 1. Name classification log4j: log for javalogBack log description Note: by default, springBoot integrates logback logs 2. Log classification Root log: Global log rootlogger (log level of springboot: info) Sub log: package log logger 3. Log level OFF = "ERROR =" WARN ...

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 ...

What is Maven? Now we need to use many third-party class libraries to build a project. For example, writing a Web project using Spring requires a large number of jar packages. The number of jar packages in a project often makes us stunned, and the relationship between jar packages is complex. One jar package often references other jar pack ...

1.Mybatis: First meet Mybatis: Introduction to MyBatis Environmental description: jdk 8 +MySQL 5.7.19maven-3.6.1IDEA Before learning, you need to master: JDBCMySQLJava FoundationMavenJunit What is Mybatis: MyBatis is an excellent persistence layer framework MyBatis avoids almost all JDBC code and the process of manually setting param ...

Annotation and reflection Annotation annotation effect It is not the procedure itself, which can be explainedIt can be read by other programs (such as compiler, etc.) Format of annotation The annotation exists in the code as "@ annotation name", and some parameter values can be added Where is annotation used? It can be atta ...

catalogue 1, Understand the idea of layered programming 2, Composition of DAO design pattern and development of each part 2.1 general 2.2 role of Dao mode 2.3 composition of Dao mode   3, Adding, deleting, modifying and searching the console version of library information management system based on DAO mode 3.1 preparation process ...

catalogue 1. Spring boot simplifies Mybatis 1.1 project integration 1.1.1 create project 1.1.2 import jar package 1.1.3 delete redundant files 1.1.4 description of main startup exceptions 1.1.5 modify YML configuration file and pojo class   1.1.6 submit Mapper interface to container management   1.1.7 edit test class 2. Ba ...