SpringBoot（五） SpringBoot整合mybatis

一：项目结构：

二：pom文件如下：

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
       <version>2.0.4.RELEASE</version>
    </parent>

    <dependencies>
        <!-- Spring-Mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.0</version>
            </dependency>
        <!-- jdbcTemplate -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
         
        <!-- MySQL连接 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!-- Add typical dependencies for a web application -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        
  </dependencies> 

三：数据库配置：

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.168.1.20:3306/test
    username: root
    password: root123

四：代码说明：

最开始使用mybati比较麻烦，各种配置文件、实体类、dao层映射关联、还有一大推其它配置。当然mybatis也发现了这种弊端，初期开发了generator可以根据表结果自动生产实体类、配置文件和dao层代码，可以减轻一部分开发量；后期也进行了大量的优化可以使用注解了。

于是两种使用方式都介绍一下，一、无配置注解版 二、配置文件版

1.无配置文件注解版
加入配置文件
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实体类User.class

package cn.saytime.bean;
 
import java.util.Date;
 
/**
 * @ClassName cn.saytime.bean.User
 * @Description
 * @date 2017-07-04 22:47:28
 */
public class User {
 
    private int id;
    private String username;
    private int age;
    private Date ctm;
 
    public User() {
    }
 
    public User(String username, int age) {
        this.username = username;
        this.age = age;
        this.ctm = new Date();
    }
 
    // Getter、Setter

package cn.saytime.mapper;
 
import cn.saytime.bean.User;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
 
import java.util.List;
 
// @Mapper 这里可以使用@Mapper注解，但是每个mapper都加注解比较麻烦，所以统一配置@MapperScan在扫描路径在application类中
public interface UserMapper {
 
    @Select("SELECT * FROM tb_user WHERE id = #{id}")
    User getUserById(Integer id);
 
    @Select("SELECT * FROM tb_user")
    public List<User> getUserList();
 
    @Insert("insert into tb_user(username, age, ctm) values(#{username}, #{age}, now())")
    public int add(User user);
 
    @Update("UPDATE tb_user SET username = #{user.username} , age = #{user.age} WHERE id = #{id}")
    public int update(@Param("id") Integer id, @Param("user") User user);
 
    @Delete("DELETE from tb_user where id = #{id} ")
    public int delete(Integer id);

————————————————

UserService.class

package cn.saytime.service;
 
import cn.saytime.bean.User;
import org.springframework.stereotype.Service;
 
import java.util.List;
 
/**
 * @ClassName cn.saytime.service.UserService
 * @Description
 */
public interface UserService {
 
    User getUserById(Integer id);
 
    public List<User> getUserList();
 
    public int add(User user);
 
    public int update(Integer id, User user);
 
    public int delete(Integer id);

UserServiceimpl.class

package cn.saytime.service.impl;
 
import cn.saytime.bean.User;
import cn.saytime.mapper.UserMapper;
import cn.saytime.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
import java.util.List;
 
/**
 * @ClassName cn.saytime.service.impl.UserServiceImpl
 * @Description
 */
@Service
public class UserServiceImpl implements UserService {
 
    @Autowired
    private UserMapper userMapper;
 
    @Override
    public User getUserById(Integer id) {
        return userMapper.getUserById(id);
    }
 
    @Override
    public List<User> getUserList() {
        return userMapper.getUserList();
    }
 
    @Override
    public int add(User user) {
        return userMapper.add(user);
    }
 
    @Override
    public int update(Integer id, User user) {
        return userMapper.update(id, user);
    }
 
    @Override
    public int delete(Integer id) {
        return userMapper.delete(id);
    }
}

JsonResult.class 通用json返回类：


package cn.saytime.bean;
 
public class JsonResult {
 
    private String status = null;
 
    private Object result = null;
 
    public JsonResult status(String status) {
        this.status = status;
        return this;
    }
 
    // Getter Setter

UserController.class（Restful风格）

package cn.saytime.web;
 
import cn.saytime.bean.JsonResult;
import cn.saytime.bean.User;
import cn.saytime.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
 
import java.util.List;
 
/**
 * @ClassName cn.saytime.web.UserController
 * @Description
 * @date 2017-07-04 22:46:14
 */
@RestController
public class UserController {
 
    @Autowired
    private UserService userService;
 
    /**
     * 根据ID查询用户
     * @param id
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserById (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            User user = userService.getUserById(id);
            r.setResult(user);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
 
    /**
     * 查询用户列表
     * @return
     */
    @RequestMapping(value = "users", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserList (){
        JsonResult r = new JsonResult();
        try {
            List<User> users = userService.getUserList();
            r.setResult(users);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
 
    /**
     * 添加用户
     * @param user
     * @return
     */
    @RequestMapping(value = "user", method = RequestMethod.POST)
    public ResponseEntity<JsonResult> add (@RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            int orderId = userService.add(user);
            if (orderId < 0) {
                r.setResult(orderId);
                r.setStatus("fail");
            } else {
                r.setResult(orderId);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
 
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
 
    /**
     * 根据id删除用户
     * @param id
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.DELETE)
    public ResponseEntity<JsonResult> delete (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            int ret = userService.delete(id);
            if (ret < 0) {
                r.setResult(ret);
                r.setStatus("fail");
            } else {
                r.setResult(ret);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
 
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
 
    /**
     * 根据id修改用户信息
     * @param user
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.PUT)
    public ResponseEntity<JsonResult> update (@PathVariable("id") Integer id, @RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            int ret = userService.update(id, user);
            if (ret < 0) {
                r.setResult(ret);
                r.setStatus("fail");
            } else {
                r.setResult(ret);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
 
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }
 
}

Application.java

package cn.saytime;
 
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@SpringBootApplication
@MapperScan("cn.saytime.mapper")
public class SpringbootMybaitsApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(SpringbootMybaitsApplication.class, args);
    }

测试：

使用PostMan通过测试： http://localhost:8080/user/1

2.配置文件版

加入配置文件

 代码部分，相比于上面那种方式，改变的只有配置文件以及下面几个部分UserMapper.class

package cn.saytime.mapper;
 
import cn.saytime.bean.User;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;
import org.springframework.stereotype.Repository;
 
import java.util.List;
 
/**
 * @ClassName cn.saytime.mapper.UesrMapper
 * @Description
 */
@Repository
public interface UserMapper {
 
    User getUserById(Integer id);
 
    public List<User> getUserList();
 
    public int add(User user);
 
    public int update(@Param("id") Integer id, @Param("user") User user);
 
    public int delete(Integer id);

}


UserServiceImpl类：

import java.util.List;

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

import org.springframework.stereotype.Service;

import com.demo.dao.UserDao;
import com.demo.mapper.User;
import com.demo.mapper.UserMapper1;
import com.demo.service.UserService;

@Service
public class UserServiceImpl implements UserService{

@Autowired
private UserDao userDao;

@Autowired
private UserMapper1 userMapper;

@Override
public User getUserById(Integer id) {
return userMapper.getUserById(id);
}

@Override
public List<User> getUserList() {
return userMapper.getUserList();
}

}

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <typeAliases>
    </typeAliases>
</configuration>

userMapper.xml

<?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="cn.saytime.mapper.UserMapper" >
    <resultMap id="BaseResultMap" type="cn.saytime.bean.User" >
        <id column="id" property="id" jdbcType="INTEGER" />
        <result column="username" property="username" jdbcType="VARCHAR" />
        <result column="age" property="age" jdbcType="INTEGER" />
        <result column="ctm" property="ctm" jdbcType="TIMESTAMP"/>
    </resultMap>
 
    <sql id="Base_Column_List" >
        id, username, age, ctm
    </sql>
 
    <select id="getUserList" resultMap="BaseResultMap"  >
        SELECT
        <include refid="Base_Column_List" />
        FROM tb_user
    </select>
 
    <select id="getUserById" parameterType="java.lang.Integer" resultMap="BaseResultMap" >
        SELECT
        <include refid="Base_Column_List" />
        FROM tb_user
        WHERE id = #{id}
    </select>
 
    <insert id="add" parameterType="cn.saytime.bean.User" >
        INSERT INTO
        tb_user
        (username,age,ctm)
        VALUES
        (#{username}, #{age}, now())
    </insert>
 
    <update id="update" parameterType="java.util.Map" >
        UPDATE
        tb_user
        SET
        username = #{user.username},age = #{user.age}
        WHERE
        id = #{id}
    </update>
 
    <delete id="delete" parameterType="java.lang.Integer" >
        DELETE FROM
        tb_user
        WHERE
        id = #{id}
    </delete>
</mapper>

测试方法同上：http://localhost:8080/user/1

五、简要说明：
不知道大家有没有注意到一点，就是引入Springboot-mybatis依赖的时候，并不是spring官方的starter，往常的springboot集成的依赖，比如web，redis等，groupId以及artifactId的地址如下：

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
而这里是mybatis为spring提供的starter依赖，所以依赖地址是：

<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.0</version>
</dependency>
而且值得注意的是，这里必须要指定版本号，往常我们使用springboot之所以不需要指定版本号，是因为我们引入的Maven Parent 中指定了SpringBoot的依赖，SpringBoot官方依赖Pom文件中已经指定了它自己集成的第三方依赖的版本号，对于Mybatis，Spring官方并没有提供自己的starter，所以必须跟正常的maven依赖一样，要加版本号。
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