springBoot 整合Mybatis （mapper自动生成）
1、pom文件（以下标红位置是特别注意的 不导入mybatis依赖@MapperScan注解无法导包--会导致访问产生404）
<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.dm</groupId>
<artifactId>myjob</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>myjob</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.5</version>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.3</version>
</dependency>
<!-- 数据库驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.6</version>
</dependency>
<!-- 数据库连接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.10</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<classifier>exec</classifier>
</configuration>
</plugin>
<!-- mybatis generator 自动生成代码插件 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.2</version>
<configuration>
<!-- 自动生成代码的配置文件地址 -->
<configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
<verbose>true</verbose>
<overwrite>true</overwrite>
</configuration>
</plugin>
</plugins>
</build>
</project>
2、配置generatorConfig.xml文件
<configuration>
<!-- 自动生成代码的配置文件地址 -->
<configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
<verbose>true</verbose>
<overwrite>true</overwrite>
</configuration>
代码贴上
<?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>
<!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
<classPathEntry location="D:\settingSelf\repository\mysql\mysql-connector-java\6.0.6\mysql-connector-java-6.0.6.jar"/>
<context id="DB2Tables" targetRuntime="MyBatis3">
<commentGenerator>
<property name="suppressDate" value="true"/>
<!-- 是否去除自动生成的注释 true：是 ： false:否 -->
<property name="suppressAllComments" value="true"/>
</commentGenerator>
<!--数据库链接URL，用户名、密码 Camp;useUnicode=trueamp;characterEncoding=utf-8amp;useSSL=false-->
<jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/bootmybatisone?serverTimezone=UTC" userId="root" password="root">
</jdbcConnection>
<javaTypeResolver>
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!-- 生成模型的包名和位置-->
<javaModelGenerator targetPackage="com.dm.myjob.mapper" targetProject="src/main/java">
<property name="enableSubPackages" value="true"/>
<property name="trimStrings" value="true"/>
</javaModelGenerator>
<!-- 生成映射文件的包名和位置-->
<sqlMapGenerator targetPackage="mapping" targetProject="src/main/resources">
<property name="enableSubPackages" value="true"/>
</sqlMapGenerator>
<!-- 生成DAO的包名和位置-->
<javaClientGenerator type="XMLMAPPER" targetPackage="com.dm.myjob.model" targetProject="src/main/java">
<property name="enableSubPackages" value="true"/>
</javaClientGenerator>
<!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
<table tableName="test" domainObjectName="Dept" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
</context>
</generatorConfiguration>
3、配置yml文件（yml文件与properties同样 写法比较简单 但是如果同时编辑properties的优先级高于yml）
server:
port: 8082
spring:
datasource:
name: bootmybatisone
url: jdbc:mysql://localhost:3306/bootmybatisone?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=false
#jdbc:mysql://cdb-a1z7n8qw.bj.tencentcdb.com:10039/KY?serverTimezone=GMT%2B8&useSSL=false
username: root
password: root
# 使用druid数据源
type: com.alibaba.druid.pool.DruidDataSource
#cdb-a1z7n8qw.bj.tencentcdb.com
driver-class-name: com.mysql.jdbc.Driver
filters: stat
maxActive: 20
initialSize: 1
maxWait: 60000
minIdle: 1
timeBetweenEvictionRunsMillis: 60000
minEvictableIdleTimeMillis: 300000
validationQuery: select 'x'
testWhileIdle: true
testOnBorrow: false
testOnReturn: false
poolPreparedStatements: true
maxOpenPreparedStatements: 20
mybatis:
mapper-locations: classpath:mapping/*.xml #classpath就是应用程序resources的路径
type-aliases-package: com.dm.myjob
4、生成mapper
即可生成如下工程样子
5、测试代码
controller层
package com.dm.myjob.controller;
import com.dm.myjob.mapper.Dept;
import com.dm.myjob.model.DeptMapper;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import javax.annotation.Resource;
import java.util.List;
/* *
* @ProjectName: myjob
* @ClassName: Test
* @Author: Dm
* @Date: 2020/6/23
*/
@Controller
@RequestMapping(value = "/test")
public class Test {
@Resource
private DeptMapper deptMapper;
@ResponseBody
@RequestMapping(value = "/select")
public String select(){
Dept list= deptMapper.selectByPrimaryKey(20);
String s = "hello! ";
if( list.getClass()!= null) {
s += "Firstname:" + list.getFirstName()+ "LastName:" + list.getLastName();
System.out.println("s = " + s);
}
return s;
}
}
附带上mapper.xml文件
<?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="com.dm.myjob.model.DeptMapper" >
<resultMap id="BaseResultMap" type="com.dm.myjob.mapper.Dept" >
<result column="id" property="id" jdbcType="INTEGER" />
<result column="magic_id" property="magicId" jdbcType="VARCHAR" />
<result column="first_name" property="firstName" jdbcType="VARCHAR" />
<result column="last_name" property="lastName" jdbcType="VARCHAR" />
</resultMap>
<insert id="insert" parameterType="com.dm.myjob.mapper.Dept" >
insert into test (id, magic_id, first_name,
last_name)
values (#{id,jdbcType=INTEGER}, #{magicId,jdbcType=VARCHAR}, #{firstName,jdbcType=VARCHAR},
#{lastName,jdbcType=VARCHAR})
</insert>
<select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
select *
from test
where id =#{id}
</select>
<insert id="insertSelective" parameterType="com.dm.myjob.mapper.Dept" >
insert into test
<trim prefix="(" suffix=")" suffixOverrides="," >
<if test="id != null" >
id,
</if>
<if test="magicId != null" >
magic_id,
</if>
<if test="firstName != null" >
first_name,
</if>
<if test="lastName != null" >
last_name,
</if>
</trim>
<trim prefix="values (" suffix=")" suffixOverrides="," >
<if test="id != null" >
#{id,jdbcType=INTEGER},
</if>
<if test="magicId != null" >
#{magicId,jdbcType=VARCHAR},
</if>
<if test="firstName != null" >
#{firstName,jdbcType=VARCHAR},
</if>
<if test="lastName != null" >
#{lastName,jdbcType=VARCHAR},
</if>
</trim>
</insert>
</mapper>
启动类MyjobApplication
package com.dm.myjob;
import org.apache.ibatis.annotations.Mapper;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
@SpringBootApplication
//@ComponentScan(basePackages = {"com.dm.myjob.model"})
@MapperScan("com.dm.myjob.model")
//这里需要注意到的是 如果不加@MapperScan注解
//导致扫描不到 报错A component required a bean of type 'com.dm.myjob.model.DeptMapper' that could not be found.
//@ComponentScan 注解和@MapperScan作用类似
@ComponentScan：此注解是用来管理容器中的bean，即是管理项目中类的依赖关系， 注意此注解并不创建类的实例； 默认情况下此注解扫描本工程下的所有包， 但是在springBoot的分布式中如果需要用到别的微服务工程中的实例，那么就要写为如下的形式。注意要加上本工程。 因为当使用 basePackages时，此注解就不会使用默认的扫描路径了
@ComponentScan(basePackages = {
"com.wisdombud.dth.boss.customer", "com.wisdombud.dth.boss.his",
"com.wisdombud.dth.boss.product.srv",
"com.wisdombud.dth.boss.product.mapper" })
@MapperScan： 此注解是扫描被此注解中声明的mapper路径下的*mapper.xml文件，读取文件配置，并根据此文件中的mapper接口路径创建bean实例。如下写法。
public class MyjobApplication {
public static void main(String[] args) {
SpringApplication.run(MyjobApplication.class, args);
}
}
6、访问（用postman客户端输入路径和端口可以看到结果）