springboot整合mybatis完整示例, mapper注解方式和xml配置文件方式实现(我们要优雅地编程)

一、注解方式

    <dependency>

        <groupId>org.mybatis.spring.boot</groupId>

        <artifactId>mybatis-spring-boot-starter</artifactId>

        <version>2.0.0</version>

    </dependency>

     <dependency>

        <groupId>mysql</groupId>

        <artifactId>mysql-connector-java</artifactId>

    </dependency>

	<!--lombok-->

	<dependency>

		<groupId>org.projectlombok</groupId>

		<artifactId>lombok</artifactId>

		<version>1.16.10</version>

	</dependency>

说明: springboot版本: 2.1.5.RELEASE

application.properties

# mysql

spring.datasource.url=jdbc:mysql://212.64.xxx.xxx:3306/test?autoR&useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true

spring.datasource.username=xxx

spring.datasource.password=xxx

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

3.在启动类中添加对 mapper 包扫描@MapperScan

package com.wangzaiplus.test;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.annotation.Bean;

import org.springframework.web.cors.CorsConfiguration;

import org.springframework.web.cors.UrlBasedCorsConfigurationSource;

import org.springframework.web.filter.CorsFilter;

@SpringBootApplication

@MapperScan("com.wangzaiplus.test.mapper")

public class TestApplication {

	public static void main(String[] args) {

		SpringApplication.run(TestApplication.class, args);

	}

	/**

	 * 跨域

	 * @return

	 */

	@Bean

	public CorsFilter corsFilter() {

		final UrlBasedCorsConfigurationSource urlBasedCorsConfigurationSource = new UrlBasedCorsConfigurationSource();

		final CorsConfiguration corsConfiguration = new CorsConfiguration();

		corsConfiguration.setAllowCredentials(true);

		corsConfiguration.addAllowedOrigin("*");

		corsConfiguration.addAllowedHeader("*");

		corsConfiguration.addAllowedMethod("*");

		urlBasedCorsConfigurationSource.registerCorsConfiguration("/**", corsConfiguration);

		return new CorsFilter(urlBasedCorsConfigurationSource);

	}

}

说明: springboot项目添加corsFilter解决跨域问题

也可以直接在 Mapper 类上面添加注解@Mapper

mapper

package com.wangzaiplus.test.mapper;

import com.wangzaiplus.test.pojo.User;

import org.apache.ibatis.annotations.*;

import org.apache.ibatis.type.JdbcType;

import java.util.List;

public interface UserMapper {

    @Select("select * from user")

    @Results({

            @Result(property = "username", column = "username", jdbcType = JdbcType.VARCHAR),

            @Result(property = "password", column = "password")

    })

    List<User> selectAll();

    @Select("select * from user where id = #{id}")

    @Results({

            @Result(property = "username", column = "username", jdbcType = JdbcType.VARCHAR),

            @Result(property = "password", column = "password")

    })

    User selectOne(Integer id);

    @Insert("insert into user(username, password) values(#{username}, #{password})")

    void insert(User user);

    @Update("update user set username=#{username}, password=#{password} where id = #{id}")

    void update(User user);

    @Delete("delete from user where id = #{id}")

    void delete(Integer id);

}

controller

package com.wangzaiplus.test.controller;

import com.wangzaiplus.test.pojo.User;

import com.wangzaiplus.test.service.UserService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController

@RequestMapping("/user")

public class UserController {

    @Autowired

    private UserService userService;

    @GetMapping("users")

    public String getAll() {

        List<User> users = userService.getAll();

        return users.toString();

    }

    @GetMapping("{id}")

    public String getOne(@PathVariable Integer id) {

        User user = userService.getOne(id);

        return user + "";

    }

    @PostMapping

    public String add(User user) {

        userService.add(user);

        return "nice";

    }

    @PutMapping

    public String update(User user) {

        userService.update(user);

        return "nice";

    }

    @DeleteMapping("{id}")

    public String delete(@PathVariable Integer id) {

        userService.delete(id);

        return "nice";

    }

}

说明: restful接口风格

service

package com.wangzaiplus.test.service;

import com.wangzaiplus.test.pojo.User;

import java.util.List;

public interface UserService {

    List<User> getAll();

    User getOne(Integer id);

    void add(User user);

    void update(User user);

    void delete(Integer id);

}

impl

package com.wangzaiplus.test.service.impl;

import com.wangzaiplus.test.mapper.UserMapper;

import com.wangzaiplus.test.pojo.User;

import com.wangzaiplus.test.service.UserService;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import java.util.List;

@Service

public class UserServiceImpl implements UserService {

    @Autowired

    private UserMapper userMapper;

    @Override

    public List<User> getAll() {

        return userMapper.selectAll();

    }

    @Override

    public User getOne(Integer id) {

        return userMapper.selectOne(id);

    }

    @Override

    public void add(User user) {

        userMapper.insert(user);

    }

    @Override

    public void update(User user) {

        userMapper.update(user);

    }

    @Override

    public void delete(Integer id) {

        userMapper.delete(id);

    }

}

说明: 仅供示例, 逻辑严谨性暂不考虑

pojo

package com.wangzaiplus.test.pojo;

import lombok.Data;

@Data

public class User {

    private Integer id;

    private String username;

    private String password;

}

说明: @Data lombok

9.sql

CREATE TABLE `user` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `username` varchar(100) COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT '',

  `password` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT '',

  PRIMARY KEY (`id`),

  UNIQUE KEY `unq_username` (`username`)

) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

接口请求

add

springboot整合mybatis完整示例, mapper注解方式和xml配置文件方式实现(我们要优雅地编程)

update

springboot整合mybatis完整示例, mapper注解方式和xml配置文件方式实现(我们要优雅地编程)

delete

springboot整合mybatis完整示例, mapper注解方式和xml配置文件方式实现(我们要优雅地编程)

getOne

springboot整合mybatis完整示例, mapper注解方式和xml配置文件方式实现(我们要优雅地编程)

getAll

springboot整合mybatis完整示例, mapper注解方式和xml配置文件方式实现(我们要优雅地编程)

说明: 截图请求参数id与数据库id不对应问题, 这是由于我接口文档默认值设为1或2的, 请求成功后接口管理工具自动刷新显示默认值id=1了, 所以看着好像不对, 实际没问题

以上代码均通过测试

二、xml方式

pom文件<build>节点下添加

		<resources>

			<resource>

				<directory>src/main/java</directory>

				<includes>

					<include>**/*.xml</include>

				</includes>

			</resource>

		</resources>

说明: 如果不添加此节点mybatis的mapper.xml文件都会被漏掉, 会出现org.apache.ibatis.binding.BindingException Invalid bound statement (not found)异常

mapper java

package com.wangzaiplus.test.mapper;

import com.wangzaiplus.test.pojo.User;

import java.util.List;

public interface UserMapper {

    List<User> selectAll();

    User selectOne(Integer id);

    void insert(User user);

    void update(User user);

    void delete(Integer id);

}

说明: 不需要@Select @Insert等注解了

新建UserMapper.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.wangzaiplus.test.mapper.UserMapper" >

    <resultMap id="BaseResultMap" type="com.wangzaiplus.test.pojo.User" >

        <id column="id" property="id" jdbcType="INTEGER" />

        <result column="username" property="username" jdbcType="VARCHAR" />

        <result column="password" property="password" jdbcType="VARCHAR" />

    </resultMap>

    <sql id="Base_Column_List" >

        id, username, password

    </sql>

    <select id="selectAll" resultMap="BaseResultMap">

        SELECT

        <include refid="Base_Column_List" />

        FROM user

    </select>

    <select id="selectOne" parameterType="int" resultMap="BaseResultMap">

        SELECT

        <include refid="Base_Column_List" />

        FROM user

        WHERE id = #{id}

    </select>

    <insert id="insert" parameterType="com.wangzaiplus.test.pojo.User">

        INSERT INTO user(username, password) VALUES (#{username}, #{password})

    </insert>

    <update id="update" parameterType="com.wangzaiplus.test.pojo.User">

        UPDATE user SET

        <if test="username != null">

            username = #{username},

        </if>

        <if test="password != null">

            password = #{password}

        </if>

        WHERE id = #{id}

    </update>

    <delete id="delete" parameterType="int">

        DELETE FROM user WHERE id =#{id}

    </delete>

</mapper>

说明: 相当于将上个版本@Select @Insert注解用xml配置文件形式代替而已

其他都不需要修改

参考文章: https://www.cnblogs.com/ityouknow/p/6037431.html