SpringBoot学习之路：04.Spring Boot集成Mybatis操作数据库

前面说了Spring Boot的使用Jpa操作数据库，今天要说是Spring Boot集目前比较受欢迎的持久层框架Mybatis，我个人对mybatis是比较喜欢的，接下来我们在SpringBoot中集成它，我们依旧使用mysql做例子，编写一个简单的用户模块的CRUD的例子。

1.项目依赖包的引入

<dependency>

<groupId>org.mybatis.spring.boot</groupId>

<artifactId>mybatis-spring-boot-starter</artifactId>

<version>1.2.0</version>

</dependency>

2.配置文件写入配置

mybatis:

type-aliases-package: com.maxbill.web.model

mapper-locations: classpath:com/maxbill/web/mapper/*.xml

注意：type-aliases-package配置别名扫描包， mapper-locations配置mapper配置文件

3.设计数据库表结构

4.使用Mybatis-Generator生成mapper和model文件

我们使用mybatis-generator插件来生成dao层的mapper文件和用户model类；mybatis-generator使用有三种方式：1.命令行，2.eclipse插件，3.maven插件；我们的工程是使用maven构建的，所以我们使用四三种方式：

1.在pom中引入mybatis-generator插件的依赖：

<plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.5</version> <configuration> <configurationFile>src/main/resources/mybatis-generator/generatorConfig.xml</configurationFile> <verbose>true</verbose> <overwrite>true</overwrite> </configuration> <dependencies> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.2</version> </dependency> </dependencies> </plugin>

2.修改插件的配置文件

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config\_1\_0.dtd"> <generatorConfiguration>  <classPathEntry location="D:\\Java\\Javafiles\\JAR\\mysql-connector-java-5.1.7-bin.jar"/> <context id="DB2Tables" targetRuntime="MyBatis3"> <commentGenerator> <property name="suppressAllComments" value="true"/> </commentGenerator>

1    <jdbcConnection
2            driverClass="com.mysql.jdbc.Driver"
3            connectionURL="jdbc:mysql://127.0.0.1:3306/blog"
4            userId="root"
5            password="admin">
6    </jdbcConnection>
7
8    <javaTypeResolver>
9        <property name="forceBigDecimals" value="false"/>
10    </javaTypeResolver>
11
12    <!-- 生成模型的包名和位置 -->
13    <javaModelGenerator targetPackage="com.maxbill.web.model" targetProject="d:\\Data">
14        <property name="enableSubPackages" value="true"/>
15        <property name="trimStrings" value="true"/>
16    </javaModelGenerator>
17
18    <!-- 生成的映射文件包名和位置 -->
19    <sqlMapGenerator targetPackage="com.maxbill.web.mapper" targetProject="d:\\Data">
20        <property name="enableSubPackages" value="true"/>
21    </sqlMapGenerator>
22
23    <!-- 生成DAO的包名和位置 -->
24    <javaClientGenerator type="XMLMAPPER" targetPackage="com.maxbill.web.mapper"

targetProject="d:\Data"> <property name="enableSubPackages" value="true"/> </javaClientGenerator>

    <table tableName="s\_user" domainObjectName="User" enableCountByExample="true"

enableUpdateByExample="true" enableDeleteByExample="true" enableSelectByExample="true" selectByExampleQueryId="true"/> </context> </generatorConfiguration>

3.使用maven命令生成代码

看到以下的输出日志，编译成功！
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building boot 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- mybatis-generator-maven-plugin:1.3.5:generate (default-cli) @ boot ---
[INFO] Connecting to the Database
[INFO] Introspecting table s_user
[INFO] Generating Example class for table s_user
[INFO] Generating Record class for table s_user
[INFO] Generating Mapper Interface for table s_user
[INFO] Generating SQL Map for table s_user
[INFO] Saving file UserMapper.xml
[INFO] Saving file UserExample.java
[INFO] Saving file User.java
[INFO] Saving file UserMapper.java
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.922 s
[INFO] Finished at: 2017-03-16T20:16:47+08:00
[INFO] Final Memory: 12M/155M
[INFO] ------------------------------------------------------------------------

打开磁盘目录我们看到已经生成了我们需要的文件。

注意：mybatis-generator有人开发了gui版，github地址：https://github.com/astarring/mybatis-generator-gui，需要的可以使用gui版：

5.编写service层逻辑代码

用户service接口

package com.maxbill.base.service;

import com.maxbill.base.model.User;

public interface UserService {

1int saveUser(User user);
2
3int deleteUser(String userid);
4
5int deleteUser(User user);
6
7User findUserById(String userid);

}

用户service实现类

package com.maxbill.base.service.impl;

import com.maxbill.base.mapper.UserMapper; import com.maxbill.base.model.User; import com.maxbill.base.service.UserService; import org.springframework.stereotype.Service;

/** * @func 用户模块业务逻辑实现层 * @user MaxBill * @date 2017-03-15 * @mail 1370581389@qq.com */ @Service public class UserServiceImpl implements UserService {

1private UserMapper userMapper;
2
3/\*\*
4 \* 添加用户
5 \*/
6public int saveUser(User user) {
7    return this.userMapper.insertSelective(user);
8}
9
10/\*\*
11 \* 删除用户
12 \*/
13public int deleteUser(String userid) {
14    return this.userMapper.deleteByPrimaryKey(userid);
15}
16
17/\*\*
18 \* 更新用户
19 \*/
20public int updateUser(User user) {
21    return this.userMapper.updateByPrimaryKeySelective(user);
22}
23
24/\*\*
25 \* 按id查新用户
26 \*/
27public User findUserById(String userid) {
28    return this.userMapper.selectByPrimaryKey(userid);
29}

}

编写用户控制器接口方法，和上一章中一样，这里不再赘述。

6.在启动器中添加mapper扫描

package com.maxbill;

import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication @MapperScan("com.maxbill.web.mapper")//扫描mapper public class BootApplication {

1public static void main(String\[\] args) {
2    SpringApplication.run(BootApplication.class, args);
3}

}

启动项目，测试各接口都正常。

以上就是Spring Boot集成Mybatis对数据库的数据的CRUD操作。下一篇主要说一下集成pagehelper分页插件。

MaxBill（2017-03-16）