第一个Spring、第一个SpringBoot、Spring-Mybatis整合、SpringBoot-Mybatis整合

目录

• 一、第一个Spring程序
• 二、第一个SpringBoot
• 三、Spring-Mybatis整合
• 四、SpringBoot-Mybatis整合第一个程序

一、第一个Spring程序

1. 添加依赖——用以支持spring

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.2.9.RELEASE</version>
    </dependency>

2. 创建一个Hello类作为JavaBean类

public class Hello {
    private String name;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public void show(){
        System.out.println("Hello,"+ name );
    }
}

3. 将Hello类装配到Spring容器中

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!--bean就是java对象 , 由Spring创建和管理-->
    <!--使用Spring来创建对象，在Spring这些都称为Bean   -->
    <!--id = 变量名-->
    <!--class = new的对象-->
    <!--property相对于给对象中的属性设置一个值-->
    <bean id="hello" class="com.kuang.pojo.Hello">
        <property name="name" value="Spring"/>
    </bean>
</beans>

4. 测试类

//ApplicationContext这里，一旦读取了bean.xml，那么Spring容器中的所有bean都被实例化了，即在bean.xml中的所有bean都被创建了，并且所有bean都执行了无参构造方法
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
//getBean : 参数即为spring配置文件中bean的id；
//就是将容器中“hello”这个JavaBean拿出来，注入到Hello hello中；
Hello hello = (Hello) context.getBean("hello");
hello.show();

5. 测试结果
   

二、第一个SpringBoot

SpringBoot项目创建官网

1. 添加依赖

<!--pom.xml文件依赖-->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

2. 创建一个Controller类
   注意：在启动类的同级目录下，新建一个controller包，一定要在同级目录下，否则识别不到

@RestController
public class HelloController {
   @RequestMapping("/hello")
   public String hello() {
       return "Hello World";
   }  
}

3. 从主程序启动项目，浏览器发起请求，看页面返回；控制台输出了 Tomcat 访问的端口号！
   
4. 启动类

//SpringBoot启动类
@SpringBootApplication
public class UrgencyThirdApplication {

	public static void main(String[] args) {
		SpringApplication.run(UrgencyThirdApplication.class, args);
	}

}

5. 个人感觉SpringBoot实际上相当于JavaConfig类

1. @SpringBootApplication类中包含了@Configuration和@ComponentScan
	1.1. @Configuration将启动类设为配置类
	1.2. @ComponentScan可以basePackageClasses或basePackages来定义要扫描的特定包。 如果没有定义特定的包，将从声明该注解的类的包开始扫描。

三、Spring-Mybatis整合

1. 引入Spring配置文件Spring-dao.xml（以前的beans.xml）

<?xml version="1.0" encoding="GBK"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd

</beans>

2. 将Mybatis配置的数据源移到Spring-dao.xml

<?xml version="1.0" encoding="GBK"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd

	<!--DataSource:使用Spring的数据源替换Mybatis的配置 c3p0 dbcp druid
    我们这里使用Spring提供的JDBC：-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>
</beans>

3. SqlSessionFactoy，关联MyBatis

<?xml version="1.0" encoding="GBK"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd

	<!--DataSource:使用Spring的数据源替换Mybatis的配置 c3p0 dbcp druid
    我们这里使用Spring提供的JDBC：-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!--关联mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/kuang/mapper/*.xml"/>
    </bean>
</beans>

4. 注册sqlSessionTemplate，关联sqlSessionFactory

<?xml version="1.0" encoding="GBK"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd

	<!--DataSource:使用Spring的数据源替换Mybatis的配置 c3p0 dbcp druid
    我们这里使用Spring提供的JDBC：-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!--关联mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/kuang/mapper/*.xml"/>
    </bean>

    <!--SqlSessionTemplate:就是我们使用的sqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能使用构造器注入sqlSessionFactory，因为它没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory" />
    </bean>
</beans>

5. 需要UserMapper接口的UserMapperImpl 实现类，私有化sqlSessionTemplate

public class UserMapperImpl implements UserMapper {

    //我们的所有操作，都使用sqlSession来执行，在原来，现在都使用SqlsessionTemplate
    private SqlSessionTemplate sqlSession;

    public void setSqlSession(SqlSessionTemplate sqlSession) {
        this.sqlSession = sqlSession;
    }

    public List<User> selectUser() {
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

6. 将自己写的实现类，注入到Spring配置文件

<?xml version="1.0" encoding="GBK"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd

	<!--DataSource:使用Spring的数据源替换Mybatis的配置 c3p0 dbcp druid
    我们这里使用Spring提供的JDBC：-->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/mybatis?useSSL=false&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!--关联mybatis配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
        <property name="mapperLocations" value="classpath:com/kuang/mapper/*.xml"/>
    </bean>

    <!--SqlSessionTemplate:就是我们使用的sqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <!--只能使用构造器注入sqlSessionFactory，因为它没有set方法-->
        <constructor-arg index="0" ref="sqlSessionFactory" />
    </bean>
    
    <bean id="userMapper" class="com.kuang.mapper.UserMapperImpl">
        <property name="sqlSession" ref="sqlSession"/>
    </bean>
</beans>

7. 测试

    @Test
    public void test () throws IOException {

        ApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
        
        UserMapper userMapper = context.getBean("userMapper", UserMapper.class);
        for (User user : userMapper.selectUser()) {
            System.out.println(user);
        }
    }

四、SpringBoot-Mybatis整合第一个程序

1. 导入依赖

<!--Springboot需要的依赖-->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

<!--Mybatis项目需要的依赖-->
    <!--mysqlq驱动-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.12</version>
    </dependency>
    <!--mybatis-->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.4</version>
    </dependency>
    <!--junit-->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>

<!--Springboot-Mybatis整合需要的依赖-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.1</version>
</dependency>

2. application.yml文件

• 放在Resource文件夹下，SpringBoot会自己扫描到

spring:
  datasource:
    name: pro_man_sys_db
    url: jdbc:mysql://localhost:3306/pro_man_sys_db?serverTimezone=UTC
    username: root
    password: root
    driver-class-name: com.mysql.cj.jdbc.Driver
  resources:
    static-locations: classpath:/static,classpath:/resources,file:/root/uploadFiles

mybatis:
  type-aliases-package: com.shiliuzi.model
  mapper-locations: classpath:mapper/*.xml

3. 创建实体类

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {

    private Integer id;
    private String name;
    private String pwd;

}

4. 创建mapper目录以及对应的Mapper接口

@Repository
public interface UserMapper {
    public static final int age=18;
    List<User> queryUserList();
    User queryUserById(Integer id);
    int addUser(User user);
    int updateUser(User user);
    int deleteUserById(Integer id);
}

5. 配置mapper.xml文件

• 这里建议创建在resources的目录下

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--configuration core file-->
<mapper namespace="com.guo.mapper.UserMapper">

    <select id="queryUserList" resultType="User">
    </select>
</mapper>

6. 编译controller调用mapper

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @RequestMapping("/list")
    public List<User> List(){

        return userMapper.queryUserList();

    }
}