【Mybatis-Plus】02 Spring整合，基本CRUD

创建非骨架普通Maven工程：

引入Spring & MybatisPlus的依赖坐标及其它持久层依赖：

　　<properties>
        <spring.version>5.2.8.RELEASE</spring.version>
    </properties>

    <dependencies>
        
        <!-- Junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>

        <!-- Lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>

        <!-- Jdbc -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.20</version>
        </dependency>

        <!-- Mybatis-Plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus</artifactId>
            <version>3.3.2</version>
        </dependency>

        <!-- log -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.12</version>
        </dependency>

        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.30</version>
        </dependency>


        <!-- Spring -->

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aspects</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>
        

        <!-- AspectJ -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.6</version>
        </dependency>


    </dependencies>

创建一个实体类：

package cn.echo42.pojo;

import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

/**
 * @author DaiZhiZhou
 * @file MP-Spring
 * @create 2020-08-05 22:36
 */

@Data
@AllArgsConstructor
@NoArgsConstructor
@TableName("sys_user")
public class User implements Serializable {

    private static final long serialVersionUID = 8921929240003713006L;

    @TableId("user_id")
    private Integer user_id;
    private String user_name; //  @TableField("user_name")
    private String user_password; //  @TableField("user_password")
    private Integer user_status; //  @TableField("user_status")
    private Integer user_is_del; //  @TableField("user_is_del")
}

创建UserMapper接口并继承Maybatis-Plus的BaseMapper接口，同时泛型注入我们User实体类

package cn.echo42.mapper;

import cn.echo42.pojo.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;

/**
 * @author DaiZhiZhou
 * @file MP-Spring
 * @create 2020-08-05 22:42
 */
public interface UserMapper extends BaseMapper<User> {
}

简单的CRUD可以不需要UserMapper.xml，Maybatis-Plus已经在BaseMapper中帮助我们实现了

有这个传统就默认创建把：

<?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="cn.echo42.mapper.UserMapper">
</mapper>

连接数据库参数配置文件[ db.properties ]：

jdbc.driverClassName = com.mysql.cj.jdbc.Driver
jdbc.url = jdbc:mysql://localhost:3306/oa?serverTimezone=GMT
jdbc.username = root
jdbc.password = 123456

日志配置文件[ log4j.properties ]：

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# MyBatis logging configuration...
log4j.logger.org.mybatis.example.BlogMapper=TRACE
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

编写SpringXML的容器配置：

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

       xsi:schemaLocation="
       http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd

       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd
"
>

    <!-- 
        dao层的配置：核心是要产生 
        Mapper代理类对象 
        1.引入数据库配置信息 
        2.数据源配置 
        3.SqlSessionFactory 
        4.产生Mapper接口的代理类对象 
    -->
    
    <!-- 1.引入数据库配置信息 -->
    <context:property-placeholder location="classpath:db.properties" system-properties-mode="FALLBACK" />
    
    <!--2.数据源配置 -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <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>

    <!-- 3.SqlSessionFactory -->
    <bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="globalConfig" ref="globalConfig" />
        
        <!-- 加载xxMapper.xml -->
        <property name="mapperLocations">
            <array>
                <value>classpath:mapper/*Mapper.xml</value>
            </array>
        </property>
        
        <!-- 配置分页插件 -->
        <property name="plugins">
            <array>
                <bean class="com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor">
                </bean>
            </array>
        </property>
    </bean>
    
    <!-- 声明全局配置 -->
    <bean id="globalConfig" class="com.baomidou.mybatisplus.core.config.GlobalConfig">
        <!-- 指定主键自动增长类型 -->
        <property name="dbConfig" ref="dbConfig" />
    </bean>
    
    <bean id="dbConfig" class="com.baomidou.mybatisplus.core.config.GlobalConfig.DbConfig">
        <property name="idType" value="AUTO" />
    </bean>

    <!-- 4.产生Mapper接口的代理类对象 -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 需要生成代理类对象的mapper接口包 -->
        <property name="basePackage" value="cn.echo42.mapper" />
        <!-- sqlSessionFactory 的name 用于为代理类中生成SqlSession -->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
    </bean>
</beans>

中央容器XML导入Dao配置：

<?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
"
>
    <import resource="classpath:bean-xml/dao.xml" />
</beans>

简单的插入测试：

添加操作：

import cn.echo42.mapper.UserMapper;
import cn.echo42.pojo.User;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author DaiZhiZhou
 * @file MP-Spring
 * @create 2020-08-05 22:54
 */
public class MybatisPlusTest {

    @Test
    public void SpringIntegrationMP_QuickStart() {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:bean-xml/central.xml");
        UserMapper userMapper = applicationContext.getBean(UserMapper.class);

        int insert = userMapper.insert(
                new User(
                        null,
                        "阿伟001",
                        "133778",
                        1,
                        0
                )
        );

    }

}

日志打印结果：

DEBUG [main] - Creating a new SqlSession
DEBUG [main] - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@8519cb4] was not registered for synchronization because synchronization is not active
DEBUG [main] - Fetching JDBC Connection from DataSource
DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@495b0487] will not be managed by Spring
DEBUG [main] - ==>  Preparing: INSERT INTO sys_user ( user_name, user_password, user_status, user_is_del ) VALUES ( ?, ?, ?, ? ) 
DEBUG [main] - ==> Parameters: 阿伟001(String), 133778(String), 1(Integer), 0(Integer)
DEBUG [main] - <==    Updates: 1
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@8519cb4]

Process finished with exit code 0

为了更方便的测试，引入Spring-Test坐标，UserMapper自动装配，全注解测试。

Spring-Test坐标：

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
        </dependency>

测试类：

import cn.echo42.mapper.UserMapper;
import cn.echo42.pojo.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

/**
 * @author DaiZhiZhou
 * @file MP-Spring
 * @create 2020-08-05 23:07
 */

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "bean-xml/central.xml")
public class MybatisPlusAnnotationTest {

    @Autowired
    UserMapper userMapper;


}

这里有个坑，注意xml路径声明要写classpath:，不然Spring读取不到文件了

@ContextConfiguration(locations = "classpath:bean-xml/central.xml")

修改操作：

    @Test
    public void mpUpdate() {

        UpdateWrapper<User> updateWrapper = new UpdateWrapper<User>();

        updateWrapper.eq("user_id", 6); // WHERE user_id = 6

        // updateWrapper.between("id", 10, 20); WHERE id BETWEEN 10 AND 20

        int update = userMapper.update(new User(
                null,
                "杰哥001",
                "133778",
                1,
                0
        ), updateWrapper);

    }

他这里的Wrapper对象和SpringDataJPA的条件规范的条件对象极其相似

通过这个对象来注入我们的条件，这个筛选条件的方法几乎一样

修改测试结果：

DEBUG [main] - Creating a new SqlSession
DEBUG [main] - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1787f2a0] was not registered for synchronization because synchronization is not active
DEBUG [main] - Fetching JDBC Connection from DataSource
DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@784b990c] will not be managed by Spring
DEBUG [main] - ==>  Preparing: UPDATE sys_user SET user_name=?, user_password=?, user_status=?, user_is_del=? WHERE (user_id = ?) 
DEBUG [main] - ==> Parameters: 杰哥001(String), 133778(String), 1(Integer), 0(Integer), 6(Integer)
DEBUG [main] - <==    Updates: 1
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1787f2a0]

删除操作：

    @Test
    public void mpDelete() {
        UpdateWrapper<User> updateWrapper = new UpdateWrapper<User>();

        updateWrapper.eq("user_id", 6); // WHERE user_id = 6

        // updateWrapper.between("id", 10, 20); WHERE id BETWEEN 10 AND 20

        int delete = userMapper.delete(updateWrapper);
    }

同样的，因为删除只需要筛选条件就够了

日志结果打印：

DEBUG [main] - Creating a new SqlSession
DEBUG [main] - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1787f2a0] was not registered for synchronization because synchronization is not active
DEBUG [main] - Fetching JDBC Connection from DataSource
DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@42f33b5d] will not be managed by Spring
DEBUG [main] - ==>  Preparing: DELETE FROM sys_user WHERE (user_id = ?) 
DEBUG [main] - ==> Parameters: 6(Integer)
DEBUG [main] - <==    Updates: 1
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1787f2a0]

 查询操作：

参数是要求一个序列化接口类型的对象

已知的基本类型的包装类都基本符合此类型，所以小是基本使用的Integer，大到Decimal也可以

    @Test
    public void mpQuery() {
        User user = (User)this.userMapper.selectById(3);
        System.out.println(user);
    }

因为之前的驼峰转义导致实体类属性命名得更改了：

package cn.echo42.pojo;

import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

/**
 * @author DaiZhiZhou
 * @file MP-Spring
 * @create 2020-08-05 22:36
 */

@Data
@AllArgsConstructor
@NoArgsConstructor
@TableName("sys_user")
public class User implements Serializable {

    private static final long serialVersionUID = 8921929240003713006L;

    @TableId("user_id")
    private Integer userId; // private Integer user_id;

    private String userName; //  private String user_name; @TableField("user_name")

    private String userPassword; //  private String user_password; @TableField("user_password")

    private Integer userStatus; //  private Integer user_status; @TableField("user_status")

    private Integer userIsDel; //  private Integer user_is_del; @TableField("user_is_del")
}

查询结果：

DEBUG [main] - Creating a new SqlSession
DEBUG [main] - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@7d61eb55] was not registered for synchronization because synchronization is not active
DEBUG [main] - Fetching JDBC Connection from DataSource
DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@58ffcbd7] will not be managed by Spring
DEBUG [main] - ==>  Preparing: SELECT user_id,user_name,user_password,user_status,user_is_del FROM sys_user WHERE user_id=? 
DEBUG [main] - ==> Parameters: 3(Integer)
DEBUG [main] - <==      Total: 1
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@7d61eb55]
User(userId=3, userName=user02, userPassword=123456, userStatus=1, userIsDel=0)

查询操作2：

通过一个集合对象，装载一系列ID元素注入到这个方法中查询：

    @Test
    public void mpQuery2() {
        List<Serializable> list = new ArrayList<Serializable>();
        list.add(2);
        list.add(4);

        List<User> userList = userMapper.selectBatchIds(list);

        for (User user : userList) {
            System.out.println(user);
        }
    }

查询结果：

DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@2e9fda69] will not be managed by Spring
DEBUG [main] - ==>  Preparing: SELECT user_id,user_name,user_password,user_status,user_is_del FROM sys_user WHERE user_id IN ( ? , ? ) 
DEBUG [main] - ==> Parameters: 2(Integer), 4(Integer)
DEBUG [main] - <==      Total: 2
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@6c7a164b]
User(userId=2, userName=user01, userPassword=123456, userStatus=1, userIsDel=0)
User(userId=4, userName=user03, userPassword=123456, userStatus=1, userIsDel=0)

查询操作3：

使用Map集合封装筛选条件，Key即字段名称，Value即值

赋值多个条件，表示条件是连接的AND

    @Test
    public void mpQuery3() {
        Map<String, Object> columnMapping = new HashMap<String, Object>();

        columnMapping.put("user_is_del", 0);
        columnMapping.put("user_password", "123456");

        List<User> userList = userMapper.selectByMap(columnMapping);

        for (User user : userList) {
            System.out.println(user);
        }
    }

查询结果：

DEBUG [main] - Creating a new SqlSession
DEBUG [main] - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@6c7a164b] was not registered for synchronization because synchronization is not active
DEBUG [main] - Fetching JDBC Connection from DataSource
DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@c5ee75e] will not be managed by Spring
DEBUG [main] - ==>  Preparing: SELECT user_id,user_name,user_password,user_status,user_is_del FROM sys_user WHERE user_password = ? AND user_is_del = ? 
DEBUG [main] - ==> Parameters: 123456(String), 0(Integer)
DEBUG [main] - <==      Total: 3
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@6c7a164b]
User(userId=2, userName=user01, userPassword=123456, userStatus=1, userIsDel=0)
User(userId=3, userName=user02, userPassword=123456, userStatus=1, userIsDel=0)
User(userId=4, userName=user03, userPassword=123456, userStatus=1, userIsDel=0)

查询操作4：

和上面的增删改一样使用封装条件对象执行：

不过selectCount是用以查询记录数量的

    @Test
    public void mpQuery4() {

        QueryWrapper<User> userWrapper = new QueryWrapper<User>();

        // 假装这是从控制器传递过来的字符串参数
        String fromUrlParam = "user";

        userWrapper.like(fromUrlParam != null , "user_name", fromUrlParam);

        // 用来查询符合筛选条件的记录数量
        Integer integer = userMapper.selectCount(userWrapper);

        System.out.println("return rows : " + integer );
    }

查询结果：

DEBUG [main] - Creating a new SqlSession
DEBUG [main] - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@13d9cbf5] was not registered for synchronization because synchronization is not active
DEBUG [main] - Fetching JDBC Connection from DataSource
DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@246f8b8b] will not be managed by Spring
DEBUG [main] - ==>  Preparing: SELECT COUNT( 1 ) FROM sys_user WHERE (user_name LIKE ?) 
DEBUG [main] - ==> Parameters: %user%(String)
DEBUG [main] - <==      Total: 1
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@13d9cbf5]
return rows : 3

查询操作5：

用于分页操作的查询，Mybatis已经帮助我们封装好了页面对象

从这个页面对象中获取信息即可

    @Test
    public void mpQuery5() {

        IPage<User> page = new Page<User>(1, 5);

        userMapper.selectPage(page, null);

        long total = page.getTotal();

        System.out.println("TotalRecords : " + total);

        List<User> list = page.getRecords();

        for (User user : list) {
            System.out.println(user);
        }
    }

查询结果：

DEBUG [main] - Creating a new SqlSession
DEBUG [main] - SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@47c81abf] was not registered for synchronization because synchronization is not active
DEBUG [main] - Fetching JDBC Connection from DataSource
DEBUG [main] - Creating new JDBC DriverManager Connection to [jdbc:mysql://localhost:3306/oa?serverTimezone=GMT]
DEBUG [main] - JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@6c25e6c4] will not be managed by Spring
DEBUG [main] - JsqlParserCountOptimize sql=SELECT  user_id,user_name,user_password,user_status,user_is_del  FROM sys_user
DEBUG [main] - ==>  Preparing: SELECT COUNT(1) FROM sys_user 
DEBUG [main] - ==> Parameters: 
DEBUG [main] - ==>  Preparing: SELECT user_id,user_name,user_password,user_status,user_is_del FROM sys_user LIMIT ?,? 
DEBUG [main] - ==> Parameters: 0(Long), 5(Long)
DEBUG [main] - <==      Total: 5
DEBUG [main] - Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@47c81abf]
TotalRecords : 5
User(userId=1, userName=admin, userPassword=admin, userStatus=1, userIsDel=0)
User(userId=2, userName=user01, userPassword=123456, userStatus=1, userIsDel=0)
User(userId=3, userName=user02, userPassword=123456, userStatus=1, userIsDel=0)
User(userId=4, userName=user03, userPassword=123456, userStatus=1, userIsDel=0)
User(userId=5, userName=admin02, userPassword=admin02, userStatus=1, userIsDel=0)