Spring Boot 实用MyBatis做数据库操作

前言：

本项目基于maven构建，使用mybatis-spring-boot作为spring-boot项目的持久层框架

spring-boot中使用mybatis持久层框架与原spring项目使用方式和注解都不相同，需要依赖mybatis-spring-boot包

1、引入mybatis和数据库及其他项目依赖

1.1、引入mybatis依赖

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1. <!-- mybatis-spring-boot -->  
2.         <dependency>  
3.             <groupId>org.mybatis.spring.boot</groupId>  
4.             <artifactId>mybatis-spring-boot-starter</artifactId>  
5.             <version>1.1.1</version>  
6.         </dependency>  

1.2、引入mysql 驱动

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1. <!-- mysql-->  
2.         <dependency>  
3.             <groupId>mysql</groupId>  
4.             <artifactId>mysql-connector-java</artifactId>  
5.         </dependency>  

1.3、项目pom.xml一览

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1. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
2.     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">  
3.   
4.     <modelVersion>4.0.0</modelVersion>  
5.   
6.     <groupId>cn.eguid.carDeviceInfoSys</groupId>  
7.     <artifactId>carSys-web</artifactId>  
8.     <packaging>war</packaging>  
9.     <version>1.4.0-SNAPSHOT</version>  
10.     <name>carSys-web</name>  
11.   
12.     <parent>  
13.         <groupId>org.springframework.boot</groupId>  
14.         <artifactId>spring-boot-starter-parent</artifactId>  
15.         <version>1.4.0.RELEASE</version>  
16.     </parent>  
17.   
18.     <dependencies>  
19.         <!-- spring-boot web -->  
20.         <dependency>  
21.             <groupId>org.springframework.boot</groupId>  
22.             <artifactId>spring-boot-starter-web</artifactId>  
23.             <!--<exclusions> <exclusion> <groupId>org.springframework.boot</groupId>   
24.                 <artifactId>spring-boot-starter-tomcat</artifactId> </exclusion> </exclusions> -->  
25.         </dependency>  
26.         <!-- spring aop -->  
27.         <dependency>  
28.             <groupId>org.springframework.boot</groupId>  
29.             <artifactId>spring-boot-starter-aop</artifactId>  
30.         </dependency>  
31.         <!-- mysql-->  
32.         <dependency>  
33.             <groupId>mysql</groupId>  
34.             <artifactId>mysql-connector-java</artifactId>  
35.         </dependency>  
36.         <dependency>  
37.             <groupId>org.springframework.boot</groupId>  
38.             <artifactId>spring-boot-starter-jdbc</artifactId>  
39.         </dependency>  
40.         <!-- https://mvnrepository.com/artifact/redis.clients/jedis -->  
41.         <dependency>  
42.             <groupId>redis.clients</groupId>  
43.             <artifactId>jedis</artifactId>  
44.         </dependency>  
45.         <dependency>  
46.             <groupId>org.springframework.boot</groupId>  
47.             <artifactId>spring-boot-starter-test</artifactId>  
48.             <scope>test</scope>  
49.         </dependency>  
50.         <dependency>  
51.             <groupId>com.jayway.jsonpath</groupId>  
52.             <artifactId>json-path</artifactId>  
53.             <scope>test</scope>  
54.         </dependency>  
55.         <!-- mybatis-spring-boot -->  
56.         <dependency>  
57.             <groupId>org.mybatis.spring.boot</groupId>  
58.             <artifactId>mybatis-spring-boot-starter</artifactId>  
59.             <version>1.1.1</version>  
60.         </dependency>  
61.   
62.         <!-- fastjson -->  
63.         <dependency>  
64.             <groupId>com.alibaba</groupId>  
65.             <artifactId>fastjson</artifactId>  
66.             <version>1.2.17</version>  
67.         </dependency>  
68.           
69.         <dependency>  
70.             <groupId>dom4j</groupId>  
71.             <artifactId>dom4j</artifactId>  
72.             <version>1.6.1</version>  
73.         </dependency>  
74.   
75.     </dependencies>  
76.   
77.     <profiles>  
78.         <profile>  
79.             <id>production</id>  
80.             <dependencies>  
81.                 <!-- This sample is a test for the autoconfig when commons-pool is *absent*.   
82.                     In production it would be useful to enable pooling by using this dependency. -->  
83.                 <dependency>  
84.                     <groupId>commons-pool</groupId>  
85.                     <artifactId>commons-pool</artifactId>  
86.                     <type>pom.lastUpdated</type>  
87.                 </dependency>  
88.             </dependencies>  
89.         </profile>  
90.     </profiles>  
91.   
92.     <!-- Package as an executable jar -->  
93.     <build>  
94.         <plugins>  
95.             <plugin>  
96.                 <groupId>org.springframework.boot</groupId>  
97.                 <artifactId>spring-boot-maven-plugin</artifactId>  
98.             </plugin>  
99.         </plugins>  
100.     </build>  
101.     <repositories>  
102.         <repository>  
103.             <id>spring-releases</id>  
104.             <url>https://repo.spring.io/libs-release</url>  
105.         </repository>  
106.     </repositories>  
107.     <pluginRepositories>  
108.         <pluginRepository>  
109.             <id>spring-releases</id>  
110.             <url>https://repo.spring.io/libs-release</url>  
111.         </pluginRepository>  
112.     </pluginRepositories>  
113. </project>  

2、配置数据库连接参数、设置mybatis的mappers所在包以及spring-boot服务参数配置

在项目根目录下创建一个application.properties，该文件用于定义spring-boot的相关参数及数据库参数，以及配置mybatis的mappers扫描路径

如果是maven项目，application.properties放在src/main/resource/目录下

配置如下：

spring.datasource.url=jdbc:MySQL://127.0.0.1:3306/test
spring.datasource.username=root
spring.datasource.password=eguid
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.max-idle=5
spring.datasource.max-wait=10000
spring.datasource.min-idle=1
spring.datasource.initial-size=3

server.port=8088
server.session.timeout=10
server.tomcat.max-threads=800
server.tomcat.uri-encoding=UTF-8

mybatis.mapperLocations=classpath:cn/eguid/carSysWEB/mappers/*.xml

3、mybatis的dao接口及mapper.xml实现

3.1、定义mybatis的dao接口

该接口与mybatis-spring方式不同，需要加上一个@Mapper注解

@Mapper注解用于声明该接口为mybatis的dao接口

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1. package cn.eguid.carSysWeb.dao;  
2.   
3. import java.util.List;  
4.   
5. import org.apache.ibatis.annotations.Mapper;  
6. import org.apache.ibatis.annotations.Param;  
7.   
8. import cn.eguid.carSysWeb.entity.DepInfo;  
9. //使用Mapper注解声明该接口为mybatis的dao接口  
10. @Mapper  
11. public interface GetInfoDao {  
12.   
13.     public List<DepInfo> getRootInfo();  
14.   
15.     public List<DepInfo> getDepInfo(@Param(value = "parentCoding") String org_parent_coding);  
16.       
17.     public List<DepInfo> getDepInfoById(@Param(value="dep_id") String dep_id);  
18. }  

3.2、dao接口对应的mapper.xml

mapper.xml与原mybatis写法相同

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1. <!DOCTYPE mapper  
2.     PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"  
3.     "http://mybatis.org/dtd/mybatis-3-mapper.dtd">  
4.   
5. <mapper namespace="cn.eguid.carSysWeb.dao.GetInfoDao">  
6.  <resultMap type="cn.eguid.carSysWeb.entity.DepInfo" id="depMap">  
7.         <id column="org_coding" property="dep_id"/>  
8.         <result column="org_name" property="dep_name"/>  
9.         <result column="org_parent_coding" property="dep_parent_coding"/>  
10.         <result column="last_time" property="last_time"/>  
11.     </resultMap>  
12. <select id="getRootInfo" resultMap="depMap">  
13. select * from car_organization where org_parent_coding is null  
14. </select>  
15. <select id="getDepInfo" parameterType="string" resultMap="depMap">  
16. SELECT * FROM car_organization where org_parent_coding=#{parentCoding,jdbcType=VARCHAR}  
17. </select>  
18. <select id="getDepInfoById" parameterType="string" resultMap="depMap">  
19. SELECT * FROM car_organization where org_coding=#{dep_id}  
20. </select>  
21. </mapper>  

补充：

做完以上步骤，就可以在service中直接通过spring的IOC注解注入mybatis的dao实现，我这里的dao接口是GetInfoDao，所以是注入‘getInfoDao’就可以正确引用该持久层；

注意：必须在spring-boot的入口类中开启@ComponentScan注解才能扫描到项目中所有注解

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1. package cn.eguid.carSysWeb;  
2.   
3. import org.springframework.boot.SpringApplication;  
4. import org.springframework.boot.autoconfigure.SpringBootApplication;  
5. import org.springframework.boot.builder.SpringApplicationBuilder;  
6.   
7. import org.springframework.context.annotation.ComponentScan;  
8.   
9. @SpringBootApplication  
10. //开启通用注解扫描  
11. @ComponentScan  
12. public class Application extends org.springframework.boot.web.support.SpringBootServletInitializer {  
13.     /** 
14.      * 实现SpringBootServletInitializer可以让spring-boot项目在web容器中运行 
15.      */  
16.     @Override  
17.     protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {  
18.         builder.sources(this.getClass());  
19.         return super.configure(builder);  
20.     }  
21.   
22.     public static void main(String[] args) {  
23.         SpringApplication.run(Application.class, args);  
24.     }  
25. }  

5、总结：

1、spring-boot项目中使用mabatis需要依赖mybatis-spring-boot

2、需要在application.xml中定义数据库连接参数以及mybatis的mappers文件扫描路径

3、mybatis的dao接口需要加上@Mapper注解才能被spring-boot正确扫描到

4、spring-boot开启注解扫描的注解是@ComponentScan

6.让外部Tomcat运行Spring Boot项目

只需要在原项目上做两件事

1、在pom.xml中排除org.springframework.boot的内置tomcat容器

<!-- spring-boot web --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><!-- 排除内置容器，排除内置容器导出成war包可以让外部容器运行spring-boot项目--><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-tomcat</artifactId></exclusion></exclusions></dependency>

2、spring-boot入口实现SpringBootServletInitializer接口

补充：SpringBootServletInitializer接口依赖javax.servlet包，需要在pom.xml中引入该包

spring-boot入口类必须实现SpringBootServletInitializer接口的configure方法才能让外部容器运行spring-boot项目

注意：SpringBootServletInitializer接口需要依赖 javax.servlet

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1. package cn.eguid.Run;  
2.   
3. import org.springframework.boot.SpringApplication;  
4. import org.springframework.boot.autoconfigure.SpringBootApplication;  
5. import org.springframework.boot.builder.SpringApplicationBuilder;  
6. import org.springframework.boot.web.support.SpringBootServletInitializer;  
7. import org.springframework.context.annotation.ComponentScan;  
8.   
9. import cc.eguid.livepush.PushManager;  
10. import cc.eguid.livepush.PushManagerImpl;  
11. import cn.eguid.livePushServer.redisManager.RedisMQHandler;  
12.   
13. @SpringBootApplication  
14. // 开启通用注解扫描  
15. @ComponentScan  
16. public class Application extends SpringBootServletInitializer {  
17.     /** 
18.      * 实现SpringBootServletInitializer可以让spring-boot项目在web容器中运行 
19.      */  
20.     @Override  
21.     protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {  
22.         builder.sources(this.getClass());  
23.         return super.configure(builder);  
24.     }  
25.       
26.     public static void main(String[] args) {  
27.         SpringApplication.run(Application.class, args);  
28.           
29.     }  
30. }