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1. typeHandlers label Whether MyBatis sets a parameter in the PreparedStatement or takes a value from the result set, it will use the type processor to convert the obtained value into Java type in an appropriate way. The following table describes some of the default processor types (interceptions). You can override the type processor or cre ...

Execute when springboot starts: CommandLineRunner, ApplicationRunner, ApplicationListener @PostConstruct comparison Usage scenario: During the development process, we will have such a scenario: we need to perform some operations after the project is started, such as reading configuration file information, database connection, deleting tempora ...

SSM development novice guide (with educational administration system project) preface When learning the SSM framework, friends who learn Java often encounter many problems. Whether they create new projects themselves or download other people's projects and use them, they will encounter some problems that have nowhere to start. So I wrote this ...

Use Spring's @ Transactional annotation to control the scenarios in which transactions do not take effect I don't know if my friends have such an experience. When they are happy to write business code, suddenly the transaction in a method seems to fail. Then, when debug ging tracks the code, it is found that after the execution of the first st ...

SSM Three components of Java Web: Servlet, Filter and Listener; Review Java Web filter process Listener Eight: ServletRequest (2), HttpSession (2), ServletContext (2) 2: Lifecycle listener, attribute change listener 4 (HttpSession): in addition to the above two, there are two additional ones (activate passivation listener and bind unbi ...

1,spring_helloworld Use maven to build the project (Mavaen) Add the corresponding pom dependency pom.xml <dependencies> <!-- https://mvnrepository.com/artifact/org.springframework/spring-context --> <dependency> <groupId>org.springframework</groupId> <artifactId>s ...

Activiti7 1, Workflow introduction 1.1 concept Workflow is the automatic execution and management of business processes through computers. It mainly solves "the process of automatically transferring documents, information or tasks among multiple participants according to some predefined rules, so as to achieve an expected business goal ...

Spring IoC container Ioc Inversion of Control is not a technology, but a design idea In the development of Ioc, there is no need to create its own instance object, but a Spring Ioc container. The Spring container is responsible for controlling the relationship between programs, rather than being directly controlled by the code. Therefore, the ...

7, IOC of spring <bean id="hello" class="com.wang.bean.Hello" scope="singleton" init-method="init" autowire="byType" destroy-method="destroy"> <property name="userName" value="spring"></property> </bean> Container usage 1: create the object of the container and t ...

pom introduction <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.18</version> </dependency> Initialize connection In the configuration file of druid connecting to the database, there should be "init method =" init & ...