Spring-Mybatis初结合

不念不忘少年蓝@ 2021-08-29 02:42 319阅读 0赞

## Spring-MyBatis初结合 ##

### 环境： ###

*  本地数据库`wampserver`
 *  编译器
 *  数据库管理工具`Navicat`

### 步骤： ###

#### 1、打开编译器新建`Maven`项目 ####

#### 2、创建`src/main/resources`资源文件夹 ####

#### 3、打开`pom.xml`导入需要的依赖包 ####

*  `junit`依赖：

<dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>4.12</version>
          <scope>test</scope>
        </dependency>

*  `mysql`依赖：

<dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
          <version>5.1.23</version>
        </dependency>

*  `mybatis`依赖：

<dependency>
          <groupId>org.mybatis</groupId>
          <artifactId>mybatis</artifactId>
          <version>3.5.2</version>
        </dependency>

*  `mybatis-spring`依赖:

<dependency>
          <groupId>org.mybatis</groupId>
          <artifactId>mybatis-spring</artifactId>
          <version>1.3.1</version>
        </dependency>

*  4个`springframework`框架依赖：

<dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-context</artifactId>
          <version>5.0.8.RELEASE</version>
        </dependency>
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-core</artifactId>
          <version>5.0.8.RELEASE</version>
        </dependency>
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-test</artifactId>
          <version>5.0.8.RELEASE</version>
        </dependency>
        
        <dependency>
          <groupId>org.springframework</groupId>
          <artifactId>spring-jdbc</artifactId>
          <version>5.0.8.RELEASE</version>
        </dependency>

*  阿里巴巴的`druib`依赖：

<dependency>
          <groupId>com.alibaba</groupId>
          <artifactId>druid</artifactId>
          <version>1.1.22</version>
        </dependency>

**添加好以后编译器会自动下载依赖包**

#### 4、新建`src/main/java`文件夹新建`pojo`包并对应数据库的字段和数据类型，再右击自动生成`setter`、`getter`和`toString`方法 ####

User.java：

public class User { 
        private int uid;
        private String username;
        private String password;
        private int age;
        public int getUid() { 
            return uid;
        }
        public void setUid(int uid) { 
            this.uid = uid;
        }
        public String getUsername() { 
            return username;
        }
        public void setUsername(String username) { 
            this.username = username;
        }
        public String getPassword() { 
            return password;
        }
        public void setPassword(String password) { 
            this.password = password;
        }
        public int getAge() { 
            return age;
        }
        public void setAge(int age) { 
            this.age = age;
        }
        @Override
        public String toString() { 
            return "User{" +
                    "uid=" + uid +
                    ", username='" + username + '\'' +
                    ", password='" + password + '\'' +
                    ", age=" + age +
                    '}';
        }
    }

#### 5、在`src/main/resources`里新建`mappers`包存放`pojo`相对应的`XxxMapper`文件 ####

UserMapper.xml：

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="user">
        
        <select id="findUser" parameterType="cn.yznu.pojo.User" resultType="cn.yznu.pojo.User">
            SELECT
                *
            FROM
                user
            <trim prefix="where" prefixOverrides="and">
                <if test=" uid!=null and uid!='' ">
                    AND uid=#{uid}
                </if>
                <if test=" username!=null and username!='' ">
                    AND username=#{username}
                </if>
            </trim>
        </select>
        
        ······
        
    </mapper>

#### 6、在`resources`文件夹里新建`db.properties`文件 ####

jdbc.driver=com.mysql.jdbc.Driver
    jdbc.url=jdbc:mysql://localhost:3306/um?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
    jdbc.username=root
    jdbc.password=

#### 7、在`resources`文件夹里新建Spring容器配置文件取名`spring.xml` ####

*  新建数据源对象`dataSource`（连接数据库）
 *  获取`sqlSessionFactory`对象
 *  通过`sqlSessionFactory`对象获取`sqlSession`对象

![spring][]  
以上bean都会被装入到spring容器里，用Autowired即可取出，就不需要用new方法新建  
比如：

@Autowired
    DataSource dataSource;			//自动装配DataSource对象

#### 8、在`src/main/test`下写测试 ####

![format_png][]

### 文件大致架构 ###

red即可取出，就不需要用new方法新建  
比如：

@Autowired
    DataSource dataSource;			//自动装配DataSource对象

#### 8、在`src/main/test`下写测试 ####

\[外链图片转存中…(img-6x4zhIIY-1586870135539)\]

### 文件大致架构 ###

![format_png 1][]

[spring]: /images/20210813/67f8771912544532847e76c8bb153214.png
[format_png]: /images/20210813/2a63e2a237de40ee9ae78caf449e0449.png
[format_png 1]: /images/20210813/24262d3121374c02bb190ab721730c45.png