# Spring Cloud 模块使用Mybatis

Spring Cloud 模块使用Mybatis

---

模块引用Mybatis依赖

• pom.xml

<dependencies>
    <!-- eureka client的依赖 -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        <version>2.0.2.RELEASE</version>
    </dependency>
    <!-- Spring cloud 本地文件配置的依赖 -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-config</artifactId>
        <version>2.0.2.RELEASE</version>
    </dependency>
    <!-- Mybatisd的依赖  -->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.0</version>
    </dependency>
    <!-- Mysql的依赖 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.47</version>
    </dependency>
</dependencies>

对应数据库中的表建立实体类

• 数据库中的t_menu表

CREATE TABLE `NewTable` (
`id`  int(10) NOT NULL AUTO_INCREMENT ,
`name`  varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,
`price`  double(100,0) NULL DEFAULT NULL ,
`flavor`  varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL ,
`type_id`  int(11) NULL DEFAULT NULL ,
PRIMARY KEY (`id`)
)
ENGINE=InnoDB
DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci
AUTO_INCREMENT=1
ROW_FORMAT=COMPACT;

• Menu实体类

package com.li.menu.entity;
@Data
public class Menu {
    private String name;
    private Double price;
    private String flavor;
    private int type_id;
}

建立MenuMapper和对应的xml映射文件

• MenuRepository.java

package com.li.menu.repository;
import com.li.menu.entity.Menu;
import java.util.List;
public interface MenuRepository {
    public List<Menu> findAll(int index,int limit);
    public int count();
    public Menu findById(Integer id);
    public void save(Menu menu);
    public void update(Menu menu);
    public void deleteById(Integer id);
}

• MenuRepository.xml 文件位置放在resource的mapper下，该地址在配置文件中配置，让容器读到映射文件

<?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.li.menu.repository.MenuRepository">
    <!-- 分页查询 -->
    <select id="findAll" resultType="com.li.menu.entity.Menu">
        select * from t_menu limit #{index},#{limit}
    </select>
    <select id="count" resultType="int">
        select count(id) from t_menu
    </select>
    <select id="findById" parameterType="int" resultType="com.li.menu.entity.Menu">
        select * from t_menu where id=#{id}
    </select>
    <insert id="save" parameterType="com.li.menu.entity.Menu">
         insert into t_menu (name,price,flavor) values (#{name},#{price},#{flavor})
    </insert>
    <update id="update" parameterType="com.li.menu.entity.Menu">
        update t_menu set name=#{name},price=#{price},flavor=#{flavor} where id=#{id}
    </update>
    <delete id="deleteById" parameterType="int">
        delete from t_menu where id=#{id}
    </delete>
</mapper>

配置文件中配置Mybatis

• menu-dev.yml

server:
  port: 8011
spring:
  application:
    name: menu
  datasource:
    name: mysqlserver
    url: jdbc:mysql://localhost:3306/shop?useUnicode=true
    username: root
    password: root
#    driver-class-name: com.mysql.cj.jdbc.Driver
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8001/eureka/
  instance:
    prefer-ip-address: true
# Mybatis配置让Ioc扫描xml
mybatis:
  mapper-locations: classpath:/mapping/*.xml
#  type-aliases-package: com.li.menu.entity  包名省略xml中的位置

使用Mapper中的数据操作接口

• MenuControler

package com.li.menu.controller;

import com.li.menu.entity.Menu;
import com.li.menu.repository.MenuRepository;
import com.netflix.discovery.converters.Auto;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import java.util.List;

@RestController
@RequestMapping("/menu")
public class MenuController {
    
    @Autowired
    MenuRepository menuRepository;
    
    @GetMapping("/findAll/{index}/{limit}")
    public List<Menu> findall(@PathVariable("index")  int index,@PathVariable("limit") int limit){
       return menuRepository.findAll(index,limit);
    }
}

• 注意上面的代码中手动注入的MenuRepository不能被Ioc容器找到，所以应该在容器启动的时候通过扫描的方式注入Menu的Mapper，启动类加上扫描注解如下：

@SpringBootApplication
//Mybatis扫描：自动扫描注入实例对象
@MapperScan("com.li.menu.repository")
public class MenuApplication {
    public static void main(String[] args) {
        SpringApplication.run(MenuApplication.class, args);
    }
}