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

         <dependency>
             <groupId>org.mybatis.spring.bootgroupId>
             <artifactId>mybatis-spring-boot-starterartifactId>
             <version>1.1.1version>
         dependency>

1.2、引入mysql 驱动

         <dependency>
             <groupId>mysqlgroupId>
             <artifactId>mysql-connector-javaartifactId>
         dependency>

1.3、项目pom.xml一览

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

     <modelVersion>4.0.0modelVersion>

     <groupId>cn.eguid.carDeviceInfoSysgroupId>
     <artifactId>carSys-webartifactId>
     <packaging>warpackaging>
     <version>1.4.0-SNAPSHOTversion>
     <name>carSys-webname>

     <parent>
         <groupId>org.springframework.bootgroupId>
         <artifactId>spring-boot-starter-parentartifactId>
         <version>1.4.0.RELEASEversion>
     parent>

     <dependencies>

         <dependency>
             <groupId>org.springframework.bootgroupId>
             <artifactId>spring-boot-starter-webartifactId>

         <dependency>
             <groupId>org.springframework.bootgroupId>
             <artifactId>spring-boot-starter-aopartifactId>
         dependency>

         <dependency>
             <groupId>mysqlgroupId>
             <artifactId>mysql-connector-javaartifactId>
         dependency>
         <dependency>
             <groupId>org.springframework.bootgroupId>
             <artifactId>spring-boot-starter-jdbcartifactId>
         dependency>

         <dependency>
             <groupId>redis.clientsgroupId>
             <artifactId>jedisartifactId>
         dependency>
         <dependency>
             <groupId>org.springframework.bootgroupId>
             <artifactId>spring-boot-starter-testartifactId>
             <scope>testscope>
         dependency>
         <dependency>
             <groupId>com.jayway.jsonpathgroupId>
             <artifactId>json-pathartifactId>
             <scope>testscope>
         dependency>

         <dependency>
             <groupId>org.mybatis.spring.bootgroupId>
             <artifactId>mybatis-spring-boot-starterartifactId>
             <version>1.1.1version>
         dependency>


         <dependency>
             <groupId>com.alibabagroupId>
             <artifactId>fastjsonartifactId>
             <version>1.2.17version>
         dependency>

         <dependency>
             <groupId>dom4jgroupId>
             <artifactId>dom4jartifactId>
             <version>1.6.1version>
         dependency>

     dependencies>

     <profiles>
         <profile>
             <id>productionid>
             <dependencies>

     <build>
         <plugins>
             <plugin>
                 <groupId>org.springframework.bootgroupId>
                 <artifactId>spring-boot-maven-pluginartifactId>
             plugin>
         plugins>
     build>
     <repositories>
         <repository>
             <id>spring-releasesid>
             <url>https://repo.spring.io/libs-releaseurl>
         repository>
     repositories>
     <pluginRepositories>
         <pluginRepository>
             <id>spring-releasesid>
             <url>https://repo.spring.io/libs-releaseurl>
         pluginRepository>
     pluginRepositories>
 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

 package cn.eguid.carSysWeb.dao;

 import java.util.List;

 import org.apache.ibatis.annotations.Mapper;
 import org.apache.ibatis.annotations.Param;

 import cn.eguid.carSysWeb.entity.DepInfo;
 //使用Mapper注解声明该接口为mybatis的dao接口
 @Mapper
 public interface GetInfoDao {

     public List getRootInfo();

     public List getDepInfo(@Param(value = "parentCoding") String org_parent_coding);

     public List getDepInfoById(@Param(value="dep_id") String dep_id);
 }

3.2、dao接口对应的mapper.xml

mapper.xml与原mybatis写法相同

     PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
     "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

 <mapper namespace="cn.eguid.carSysWeb.dao.GetInfoDao">
  <resultMap type="cn.eguid.carSysWeb.entity.DepInfo" id="depMap">
         <id column="org_coding" property="dep_id"/>
         <result column="org_name" property="dep_name"/>
         <result column="org_parent_coding" property="dep_parent_coding"/>
         <result column="last_time" property="last_time"/>
     resultMap>
 <select id="getRootInfo" resultMap="depMap">
 select * from car_organization where org_parent_coding is null
 select>
 <select id="getDepInfo" parameterType="string" resultMap="depMap">
 SELECT * FROM car_organization where org_parent_coding=#{parentCoding,jdbcType=VARCHAR}
 select>
 <select id="getDepInfoById" parameterType="string" resultMap="depMap">
 SELECT * FROM car_organization where org_coding=#{dep_id}
 select>
 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

 package cn.eguid.carSysWeb;

 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.builder.SpringApplicationBuilder;

 import org.springframework.context.annotation.ComponentScan;

 @SpringBootApplication
 //开启通用注解扫描
 @ComponentScan
 public class Application extends org.springframework.boot.web.support.SpringBootServletInitializer {
     /**
      * 实现SpringBootServletInitializer可以让spring-boot项目在web容器中运行
      */
     @Override
     protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
         builder.sources(this.getClass());
         return super.configure(builder);
     }

     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);
     }
 }

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

org.springframework.boot
spring-boot-starter-web



org.springframework.boot
spring-boot-starter-tomcat

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

 package cn.eguid.Run;

 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.boot.web.support.SpringBootServletInitializer;
 import org.springframework.context.annotation.ComponentScan;

 import cc.eguid.livepush.PushManager;
 import cc.eguid.livepush.PushManagerImpl;
 import cn.eguid.livePushServer.redisManager.RedisMQHandler;

 @SpringBootApplication
 // 开启通用注解扫描
 @ComponentScan
 public class Application extends SpringBootServletInitializer {
     /**
      * 实现SpringBootServletInitializer可以让spring-boot项目在web容器中运行
      */
     @Override
     protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
         builder.sources(this.getClass());
         return super.configure(builder);
     }

     public static void main(String[] args) {
         SpringApplication.run(Application.class, args);

     }
 }