Spring 14: Spring + MyBatis初步整合开发

• 2022 年 8 月 28 日
• 笔记
• Spring框架

SM整合步骤

预期项目结构

新建数据库和数据表

• springuser.sql脚本如下

create database ssm;

use ssm;

create table users(
  userid int primary key,
  uname varchar(20),
  upass varchar(20)
);

create table accounts(
 aid  int primary key,
 aname varchar(20),
 acontent varchar(50)
);

新建项目

• 新建maven项目
• 选择quickstart模板
• 修改项目目录，删除自动生成的类和对应测试类

修改pom.xml文件

• 添加相关依赖

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="//maven.apache.org/POM/4.0.0" xmlns:xsi="//www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="//maven.apache.org/POM/4.0.0 //maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.example</groupId>
  <artifactId>ch09-spring-sm</artifactId>
  <version>1.0.0</version>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
  </properties>

  <dependencies>
    <!-- 添加单元测试的依赖 -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13.2</version>
      <scope>test</scope>
    </dependency>

    <!-- 添加spring-context依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.3.22</version>
    </dependency>

    <!-- 添加spring-aspects依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>5.3.22</version>
    </dependency>

    <!-- 添加spring-tx依赖，用于事务管理 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.3.22</version>
    </dependency>

    <!-- 添加spring-jdbc依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.3.22</version>
    </dependency>

    <!-- 添加mybatis依赖 -->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.10</version>
    </dependency>

    <!-- 添加mysql驱动 -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.30</version>
    </dependency>

    <!-- 添加mybatis和spring的整合依赖-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>2.0.7</version>
    </dependency>

    <!-- 添加数据库连接池 -->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.2.11</version>
    </dependency>
  </dependencies>

  <build>
    <!-- 添加资源文件指定 -->
    <resources>
      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.properties</include>
          <include>**/*.xml</include>
        </includes>
        <filtering>false</filtering>
      </resource>
      <resource>
        <directory>src/main/resources</directory>
        <includes>
          <include>**/*.properties</include>
          <include>**/*.xml</include>
        </includes>
        <filtering>false</filtering>
      </resource>
    </resources>
  </build>
</project>

添加模板文件

分别添加MyBatis相应配置文件的模板(SqlMapConfig.xml和XXXXMapper.xml文件，方便以后使用)

• 如何添加模板文件

• SqlMapConfig.xml模板配置文件

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "//mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <properties resource="db.properties"></properties>
    
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
    
    <typeAliases>
        <package name="com.example.pojo"></package>
    </typeAliases>
    
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url"
                          value="jdbc:mysql://ip:port/dataBaseName?useSSL=false&amp;serverTimezone=UTC&amp;allowPublicKeyRetrieval=true"/>
                <property name="username" value="userName"/>
                <property name="password" value="passWord"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <package name=""></package>
    </mappers>
</configuration>

• XXXXMapper.xml模板配置文件

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "//mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="">

</mapper>

jdbc.properties

• 添加jdbc.properties文件至src/main/resources目录下

jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://自己的服务器ip或localhost:3306/要连接的数据库名称?useUnicode=true&characterEncoding=utf8
jdbc.username=XXXX
jdbc.password=YYYY

SqlMapConfig.xml

• 添加SqlMapConfig.xml文件至src/main/resources目录下：选择我们自己添加的模板文件(该状态下idea无法电脑截图，手机拍摄，包涵包涵)

Spring核心配置文件

• 由于分层开发，需要添加两个配置文件：applicationContext_mapper.xml和applicationContext_service.xml。添加操作见下

• applicationContext_mapper.xml

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

    <!-- 读取数据库连接文件 jdbc.properties -->
    <context:property-placeholder location="jdbc.properties"/>

    <!-- 创建数据源 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!-- 配置SqlSessionFactoryBean类 -->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 配置数据源 -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 配置MyBatis的核心配置文件 -->
        <property name="configLocation" value="SqlMapConfig.xml"/>
        <!-- 注册实体类的别名 -->
        <property name="typeAliasesPackage" value="com.example.pojo"/>
    </bean>

    <!-- 注册mapper.xml文件 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.example.mapper"/>
    </bean>
</beans>

• applicationContext_service.xml

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

    <!-- 导入applicationContext_mapper.xml文件-->
    <import resource="applicationContext_mapper.xml"/>

    <!-- sm框架是基于注解开发的，要添加包扫描 -->
    <context:component-scan base-package="com.example.service.impl"/>

    <!-- 添加事务处理，此时先不管-->
    
</beans>

添加实体类

• 依据users数据表的字段，创建User实体类

package com.example.pojo;

public class User {
    private Integer userid;
    private String uname;
    private String upass;

    @Override
    public String toString() {
        return "User{" +
                "userid=" + userid +
                ", uname='" + uname + '\'' +
                ", upass='" + upass + '\'' +
                '}';
    }

    public Integer getUserid() {
        return userid;
    }

    public void setUserid(Integer userid) {
        this.userid = userid;
    }

    public String getUname() {
        return uname;
    }

    public void setUname(String uname) {
        this.uname = uname;
    }

    public String getUpass() {
        return upass;
    }

    public void setUpass(String upass) {
        this.upass = upass;
    }

    public User(String uname, String upass) {
        this.uname = uname;
        this.upass = upass;
    }

    public User(Integer userid, String uname, String upass) {
        this.userid = userid;
        this.uname = uname;
        this.upass = upass;
    }

    public User() {
    }
}

数据访问层

• 添加UserMapper接口

package com.example.mapper;


import com.example.pojo.User;

/**
 * 数据访问层的接口
 */
public interface UserMapper {
    int insert(User user);
}

• 添加UserMapper.xml，先选择我们自己添加的XXXMapper.xml模板文件，再进一步配置该文件

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "//mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mapper.UserMapper">

    <!--
        int insert(User user);

        private Integer userid;
        private String uname;
        private String upass;
    -->
    <insert id="insert" parameterType="user">
        insert into users values (#{userid}, #{uname}, #{upass})
    </insert>
</mapper>

业务逻辑层

• 添加UserService接口

package com.example.service;

import com.example.pojo.User;

/**
 * 业务逻辑层接口
 */
public interface UserService {
    int insert(User user);
}

• 添加UserServiceImpl实现类

package com.example.service.impl;

import com.example.mapper.UserMapper;
import com.example.pojo.User;
import com.example.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * 业务实现类
 */
@Service
public class UserServiceImpl implements UserService {
    //业务逻辑层实现类持有数据访问层的接口类型的变量
    @Autowired
    UserMapper userMapper;

    @Override
    public int insert(User user) {
        return userMapper.insert(user);
    }
}

测试

package com.example.test;

import com.example.pojo.User;
import com.example.service.UserService;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestUserInsert {

    //测试用户信息导入
    @Test
    public void testUserInsert(){
        //创建Spring容器并启动
        ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext_service.xml");
        //获取业务逻辑实现类的对象
        UserService userService = (UserService) ac.getBean("userServiceImpl");
        //调用业务功能
        int num = userService.insert(new User(1, "王小涵", "hanzhanghan"));
        if(num == 1){
            System.out.println("用户信息导入成功!");
        }else{
            System.out.println("用户信息导入失败!");
        }
    }
}

测试输出

• 控制台输出

Logging initialized using 'class org.apache.ibatis.logging.stdout.StdOutImpl' adapter.
Creating a new SqlSession
SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@475835b1] was not registered for synchronization because synchronization is not active
Aug 28, 2022 10:31:31 AM com.alibaba.druid.support.logging.JakartaCommonsLoggingImpl info
INFO: {dataSource-1} inited
JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@4d4d8fcf] will not be managed by Spring
==>  Preparing: insert into users values (?, ?, ?)
==> Parameters: 1(Integer), 王小涵(String), hanzhanghan(String)
<==    Updates: 1
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@475835b1]
用户信息导入成功!

Process finished with exit code 0

• 数据表变化