SpringBoot 2.0集成MySQL+mybatis+Druid配置

本文采用的springboot版本为2.1.4，mybatis版本为1.3.2，Druid版本为1.1.10

springboot项目骨架生成不在赘述，idea可以用spring initializr生成，或者直接到spring官网https://start.spring.io生成，下载之后导入到idea中。

1.引入jar包，pom文件如下：

[code]<?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 http://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>2.1.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>springbucks</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springbucks</name>
<description>Demo project for Spring Boot</description>

<properties>
<java.version>1.8</java.version>
</properties>

<dependencies>

<!--打开监控-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>

<!-- druid数据源 -->
<!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.10</version>
</dependency>

<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>

</project>

pom中引入了actuator监控、druid、mybatis、lombok、mysql等依赖

2.application.yml配置如下：

[code]server:
port: 8088
spring:
application:
name: spring-bucks
datasource:
druid:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost/demo?characterEncoding=UTF-8&useSSL=false
username: developer
password: developer12321
filters: stat,wall
initial-size: 3
min-idle: 1
max-active: 20
test-on-borrow: false
test-on-return: false
test-while-idle: true
validation-query: select 'x'
max-wait: 6000
pool-prepared-statements: true
time-between-eviction-runs-millis: 60000
min-evictable-idle-time-millis: 60000
web-stat-filter:
enabled: true
url-pattern: "/*"
stat-view-servlet:
enabled: true
url-pattern: /druid/*
reset-enable: false
login-username: admin
login-password: admin
mybatis:
configuration:
map-underscore-to-camel-case: true
type-handlers-package: com.example.springbucks.handler
type-aliases-package: com.example.springbucks.model
mapper-locations: classpath:mappers/*.xml
logging:
level:
com:
example:
springbucks:
dao: debug

management:
endpoints:
web:
exposure:
include: "*"

druid各项配置建议参考durid官方文档https://github.com/alibaba/druid/wiki

这里重点说几个mybatis的配置

map-underscore-to-camel-case: true

这项配置可以实现数据库表字段和类变量名的自动映射，例如列名create_time会自动映射到字段名createTime，省去写ResultMap的麻烦，这里建议大家开发时都能遵守一定的规范，可以提高效率

type-aliases-package: com.example.springbucks.model

大家知道在mapper文件中写ParameterType和ResultType时必须是全包名，很不便利，这个配置只需要写实体类的别名就行了，但是在实体类上要加入注解。如下，在mapper中，com.example.springbucks.model.Coffee可以直接用coffee代替

[code]package com.example.springbucks.model;

import lombok.*;
import lombok.experimental.Accessors;
import org.apache.ibatis.type.Alias;
import org.joda.money.Money;
import org.springframework.data.mongodb.core.mapping.Document;

import java.io.Serializable;

/**
* @author Gary
* @className Coffee
* @description TODO
* @date 2019-04-13 19:06
**/

@Document
@Data
@ToString(callSuper = true)
@EqualsAndHashCode(callSuper = false)
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
@Alias("coffee")
public class Coffee extends BaseModel implements Serializable {

private String name;

private Money price;

}

[code]    <select id="search" parameterType="coffee" resultType="coffee">
SELECT
*
FROM
t_coffee t
<where>
<if test="name != null and name != ''">
AND t.NAME LIKE LOWER( '%${name}%' )
</if>
<if test="price != null">
AND t.price = #{price}
</if>
ORDER BY id
</where>
</select>

mapper-locations: classpath:mappers/*.xml

指定mapper文件的路径

3.启动类配置

[code]@MapperScan("com.example.springbucks.dao")

启动类加入@MapperScan注解之后，spring会到相应的包下面扫描，不需要在每个dao接口里加@Mapper注解

4.dao

[code]package com.example.springbucks.dao;

import com.example.springbucks.model.Coffee;
import org.apache.ibatis.annotations.*;
import org.apache.ibatis.session.RowBounds;

import java.util.List;

/**
* TODO
*
* @author Gary
*
* @date 2019-04-13 19:24
*/
public interface CoffeeDao {

/**
* @description: 新增coffee
* @author Gary
* @param coffee
*
* @return java.lang.Long
* @date 2019-04-07 20:59
*/
@Insert("insert into t_coffee (name, price, create_time, update_time) " +
"values (#{name}, #{price}, now(), now())")
@Options(useGeneratedKeys = true)
Long save(Coffee coffee);

/**
* 根据id查询coffee
* @description:
* @author Gary
* @param id
*
* @return com.example.mybatisdemo.model.Coffee
* @date 2019-04-07 20:59
*/
@Select("select * from t_coffee where id = #{id}")
@Results({
@Result(id = true, column = "id", property = "id")
})
Coffee findById(Long id);

/**
* 分页查询
*
* @description: TODO
* @author Gary
* @param rowBounds
*
* @return java.util.List<com.example.mybatisdemo.model.Coffee>
* @date 2019-04-07 21:13
*/
@Select("select * from t_coffee order by id")
List<Coffee> findAllWithRowBounds(RowBounds rowBounds);

List<Coffee> search(Coffee coffee);

}

[code]<?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.example.springbucks.dao.CoffeeDao">

<select id="search" parameterType="coffee" resultType="coffee">
SELECT
*
FROM
t_coffee t
<where>
<if test="name != null and name != ''">
AND t.NAME LIKE LOWER( '%${name}%' )
</if>
<if test="price != null">
AND t.price = #{price}
</if>
ORDER BY id
</where>
</select>

</mapper>

5.service

[code]package com.example.springbucks.service;

import com.example.springbucks.model.Coffee;
import org.apache.ibatis.annotations.Param;

import java.util.List;

/**
* @author Gary
* @className CoffeeService
* @description TODO
* @date 2019-04-13 19:16
**/
public interface CoffeeService {

Long save(Coffee coffee);

Coffee findById(Long id);

List<Coffee> findAllByPage(@Param("pageNum") int pageNum,
@Param("pageSize") int pageSize);

List<Coffee> search(Coffee coffee);

}

[code]package com.example.springbucks.service.impl;

import com.example.springbucks.dao.CoffeeDao;
import com.example.springbucks.model.Coffee;
import com.example.springbucks.service.CoffeeService;
import org.apache.ibatis.session.RowBounds;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
* @author Gary
* @className CoffeeServiceImpl
* @description TODO
* @date 2019-04-13 19:25
**/
@Service("coffeeService")
public class CoffeeServiceImpl implements CoffeeService {

@Autowired
private CoffeeDao coffeeDao;

@Override
public Long save(Coffee coffee) {
return coffeeDao.save(coffee);
}

@Override
public Coffee findById(Long id) {
return coffeeDao.findById(id);
}

@Override
public List<Coffee> findAllByPage(int pageNum, int pageSize) {
RowBounds rowBounds = new RowBounds(pageNum, pageSize);
return coffeeDao.findAllWithRowBounds(rowBounds);
}

@Override
public List<Coffee> search(Coffee coffee) {
return coffeeDao.search(coffee);
}

}

6.启动项目之后可到http://localhost:8088/druid/login.html页面查看druid的相关信息