SSM framework integration

This is the 14th day of my participation in the August More Text Challenge

Basic dependence

1. Relevant jars

   • Jackson
   • Spring, SpringMVC, Spring JDBC
   • Mybatis, mybatis – spring
   • Druid connection pool

2. pom.xml

   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-webmvc</artifactId>
       <version>5.2.8. RELEASE</version>
   </dependency>
   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-jdbc</artifactId>
       <version>5.2.8. RELEASE</version>
   </dependency>
   <dependency>
       <groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-databind</artifactId>
       <version>2.11.2</version>
   </dependency>
   <dependency>
       <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
       <version>8.0.21</version>
   </dependency>
   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis</artifactId>
       <version>3.4.6</version>
   </dependency>
   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis-spring</artifactId>
       <version>1.3.2</version>
   </dependency>
   <dependency>
       <groupId>commons-logging</groupId>
       <artifactId>commons-logging</artifactId>
       <version>1.2</version>
   </dependency>
   <dependency>
       <groupId>com.alibaba</groupId>
       <artifactId>druid</artifactId>
       <version>1.</version>
   </dependency>
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Using XML Configuration

1. The web.xml configuration

   Configure DispatcherServlet and set up to start loading

   
           
   <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xmlns="http://xmlns.jcp.org/xml/ns/javaee"
            xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
            id="WebApp_ID" version="3.1">
       <servlet>
           <servlet-name>app</servlet-name>
           <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
           <init-param>
               <param-name>contextConfigLocation</param-name>
               <param-value>classpath:spring-config.xml</param-value>
           </init-param>
           <load-on-startup>1</load-on-startup>
       </servlet>
       <servlet-mapping>
           <servlet-name>app</servlet-name>
           <url-pattern>/</url-pattern>
       </servlet-mapping>
   </web-app>
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2. spring-config.xml

   Configure MyBatis, data source, and MapperSanner

   
           
   <beans xmlns="http://www.springframework.org/schema/beans"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xmlns:context="http://www.springframework.org/schema/context"
          xmlns:mvc="http://www.springframework.org/schema/mvc"
          xsi:schemaLocation="Http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
       <! - configure MyBatis -- -- >
       <bean id="sqlSessionFactory"
             class="org.mybatis.spring.SqlSessionFactoryBean">
           <property name="dataSource" ref="dataSource" />
           <! -- Mybatis config file -->
           <property name="configLocation"
                     value="classpath:mybatis-config.xml" />
           <! --mapper.xml -->
           <property name="mapperLocations"
                     value="classpath:mapper/*.xml" />
       </bean>
       <! -- Configure data source -->
       <! -- read the db. The properties - >
       <context:property-placeholder location="classpath:db.properties" />
       <bean id="dataSource"
             class="com.alibaba.druid.pool.DruidDataSource">
           <property name="driverClassName"
                     value="${mysql.driver}" />
           <property name="url"
                     value="${mysql.url}" />
           <property name="username" value="${mysql.username}" />
           <property name="password" value="${mysql.password}" />
       </bean>
       <! - the configuration MapperScanner -- -- >
       <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
           <property name="sqlSessionFactoryBeanName"
                     value="sqlSessionFactory" />
           <! --@Mapper Scan package -->
           <property name="basePackage" value="cade.mapper" />
       </bean>
       <! -- Configure Component scan -->
       <context:component-scan
               base-package="cade.controller" />
       <context:component-scan
               base-package="cade.service" />
       <! -- Configure MVC annotation support -->
       <mvc:annotation-driven />
        <! Configure static resource mapping -->
       <mvc:resources mapping="/static/**" location="classpath:static/" />
   </beans>
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3. mybatis-config.xml

   
           
   <! DOCTYPEconfiguration  PUBLIC "- / / mybatis.org//DTD Config / 3.0 / EN"
           "http://mybatis.org/dtd/mybatis-3-config.dtd">
   <configuration>
       <! -- Alias configuration -->
       <typeAliases>
           <package name="cade.entity" />
       </typeAliases>
   </configuration>
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Write test code

1. UserMapper

   @Mapper
   public interface UserMapper {
       List<User> listUsersAll(a);
   }
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   <mapper namespace="cade.mapper.UserMapper">
       <select id="listUsersAll" resultType="user">
           select * from user
       </select>
   </mapper>
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2. UserService

   @Service
   public class UserServiceImpl implements UserService {
   
       private final UserMapper userMapper;
   
       @Autowired
       public UserServiceImpl(UserMapper userMapper) {
           this.userMapper = userMapper;
       }
   
       @Override
       public List<User> listUsersAll(a) {
           returnuserMapper.listUsersAll(); }}Copy the code

3. UserController

   @Controller
   public class HelloController {
   
       private final UserService userService;
   
       @Autowired
       public HelloController(UserService userService) {
           this.userService = userService;
       }
   
       @ResponseBody
       @RequestMapping("/users")
       public List<User> listUsersAll(a) {
           returnuserService.listUsersAll(); }}Copy the code

4. Entity class

   public class User {
       String name;
       Integer age;
   	// ...
   }
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5. Visit/Users to test

   [{"name":"Bill"."age":20}, {"name":"Zhang"."age":23}, {"name":"Fifty"."age":23}]
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Use JavaConfig for configuration

1. The configuration class replaces web.xml

   In the Servlet 3.0 environment, the Servlet container will search implementation under the classpath javax.mail. Servlet. ServletContainerInitializer interface any class, after we use it to initialize the Servlet container

   Spring implements the above interface, implementation class called SpringServletContainerInitializer, it will in turn to search for WebApplicationInitializer any class, and delegate this class implements configuration

   , Spring 3.2 introduced a simple WebApplicationInitializer implementation class, this is AbstractAnnotationConfigDispatcherServletInitializer

   import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
   
   public class WebInit extends AbstractAnnotationConfigDispatcherServletInitializer {
       @Override
       protectedClass<? >[] getRootConfigClasses() {return null;
       }
   
       @Override
       protectedClass<? >[] getServletConfigClasses() {// Introduce the Spring Config configuration class
           return new Class[]{SpringConfig.class};
       }
   
       @Override
       protected String[] getServletMappings() {
           // Intercept the path
           return new String[]{"/"}; }}Copy the code

2. The configuration class replaces Spring-config. XML and mybatis

   Use annotations to open SpringMVC and configure beans in the Spring configuration class

   @Configuration
   @ComponentScan(basePackages = {"cade.controller", "cade.service"}) / / scanning component
   @EnableWebMvc // <mvc:annotation-driven />
   public class SpringConfig implements WebMvcConfigurer {
   
       // mybatis
       @Bean
       public SqlSessionFactoryBean sqlSessionFactory(a) {
           SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
           sqlSessionFactoryBean.setDataSource(this.dataSource());
           // Mybatis configuration file location
           Resource mybatisConfigResource = new ClassPathResource("mybatis-config.xml");
           sqlSessionFactoryBean.setConfigLocation(mybatisConfigResource);
           Mapper. XML file location
           Resource userMapperXML = new ClassPathResource("mapper/UserMapper.xml");
           sqlSessionFactoryBean.setMapperLocations(new Resource[]{userMapperXML});
           return sqlSessionFactoryBean;
       }
   
       / / the data source
       @Bean
       public DataSource dataSource(a) {
           DruidDataSource dataSource = new DruidDataSource();
           dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
           dataSource.setUrl("JDBC: mysql: / / 127.0.0.1:3306 / demo? useSSL=true&useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai");
           dataSource.setUsername("root");
           dataSource.setPassword("cade");
           return dataSource;
       }
   
       // Mapper class scan, the same function as @mapperscan
       @Bean
       public MapperScannerConfigurer initMapperScannerConfigurer(a) {
           MapperScannerConfigurer msc = new MapperScannerConfigurer();
           msc.setSqlSessionFactoryBeanName("sqlSessionFactory");
           msc.setBasePackage("cade.mapper");
           return msc;
       }
   
       // <mvc:resources mapping="/static/**" location="classpath:static/" />
       @Override
       public void addResourceHandlers(ResourceHandlerRegistry registry) {
           registry.addResourceHandler("/static/**").addResourceLocations("/static/"); }}Copy the code