spring boot集成mybatis

1.pom.xml中添加jar包依赖

 添加集成mybatis所需要的依赖包

<!-- mybatis集成springboot启动包 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <!-- mysql的jdbc依赖包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

2.配置文件中配置mapper.xml文件配置

在application.properties文件中添加mybatis文件中xml的位置所在的配置。

#mybats配置
mybatis.mapper-locations=classpath:com/example/demo/mapping/*.xml

3.配置文件中配置数据源信息

在application.properties文件中添加mybatis加载数据源的信息

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test_client?useUnicode=true&characterEncoding=UTF-8&noAccessToProcedureBodies=true&zeroDateTimeBehavior=convertToNull&serverTimezone=Asia/Shanghai

4.添加mybatis注解

我们可以在mybatis的Mapper接口中添加@Mapper注解，或者在运行的主类上添加@MapperScan(basePackages = ("com.example.demo.mapper"))注解包扫描。

---

以上步骤完成后，就可以操作数据库了。下面上代码。

首先根据数据库自动生成mybatis的代码，我这是一个简单的学生表，表结构如下：

CREATE TABLE `student` (
  `id` varchar(10) NOT NULL COMMENT '学号',
  `name` varchar(20) NOT NULL COMMENT '姓名',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

根据上面的表生成文件如下，model类：里面就是数据库的实体类

package com.example.demo.model;

public class Student {
    private String id;

    private String name;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id == null ? null : id.trim();
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }
}

package com.example.demo.model;

import java.util.ArrayList;
import java.util.List;

public class StudentExample {
    protected String orderByClause;

    protected boolean distinct;

    protected List<Criteria> oredCriteria;

    public StudentExample() {
        oredCriteria = new ArrayList<Criteria>();
    }

    public void setOrderByClause(String orderByClause) {
        this.orderByClause = orderByClause;
    }

    public String getOrderByClause() {
        return orderByClause;
    }

    public void setDistinct(boolean distinct) {
        this.distinct = distinct;
    }

    public boolean isDistinct() {
        return distinct;
    }

    public List<Criteria> getOredCriteria() {
        return oredCriteria;
    }

    public void or(Criteria criteria) {
        oredCriteria.add(criteria);
    }

    public Criteria or() {
        Criteria criteria = createCriteriaInternal();
        oredCriteria.add(criteria);
        return criteria;
    }

    public Criteria createCriteria() {
        Criteria criteria = createCriteriaInternal();
        if (oredCriteria.size() == 0) {
            oredCriteria.add(criteria);
        }
        return criteria;
    }

    protected Criteria createCriteriaInternal() {
        Criteria criteria = new Criteria();
        return criteria;
    }

    public void clear() {
        oredCriteria.clear();
        orderByClause = null;
        distinct = false;
    }

    protected abstract static class GeneratedCriteria {
        protected List<Criterion> criteria;

        protected GeneratedCriteria() {
            super();
            criteria = new ArrayList<Criterion>();
        }

        public boolean isValid() {
            return criteria.size() > 0;
        }

        public List<Criterion> getAllCriteria() {
            return criteria;
        }

        public List<Criterion> getCriteria() {
            return criteria;
        }

        protected void addCriterion(String condition) {
            if (condition == null) {
                throw new RuntimeException("Value for condition cannot be null");
            }
            criteria.add(new Criterion(condition));
        }

        protected void addCriterion(String condition, Object value, String property) {
            if (value == null) {
                throw new RuntimeException("Value for " + property + " cannot be null");
            }
            criteria.add(new Criterion(condition, value));
        }

        protected void addCriterion(String condition, Object value1, Object value2, String property) {
            if (value1 == null || value2 == null) {
                throw new RuntimeException("Between values for " + property + " cannot be null");
            }
            criteria.add(new Criterion(condition, value1, value2));
        }

        public Criteria andIdIsNull() {
            addCriterion("id is null");
            return (Criteria) this;
        }

        public Criteria andIdIsNotNull() {
            addCriterion("id is not null");
            return (Criteria) this;
        }

        public Criteria andIdEqualTo(String value) {
            addCriterion("id =", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdNotEqualTo(String value) {
            addCriterion("id <>", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdGreaterThan(String value) {
            addCriterion("id >", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdGreaterThanOrEqualTo(String value) {
            addCriterion("id >=", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdLessThan(String value) {
            addCriterion("id <", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdLessThanOrEqualTo(String value) {
            addCriterion("id <=", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdLike(String value) {
            addCriterion("id like", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdNotLike(String value) {
            addCriterion("id not like", value, "id");
            return (Criteria) this;
        }

        public Criteria andIdIn(List<String> values) {
            addCriterion("id in", values, "id");
            return (Criteria) this;
        }

        public Criteria andIdNotIn(List<String> values) {
            addCriterion("id not in", values, "id");
            return (Criteria) this;
        }

        public Criteria andIdBetween(String value1, String value2) {
            addCriterion("id between", value1, value2, "id");
            return (Criteria) this;
        }

        public Criteria andIdNotBetween(String value1, String value2) {
            addCriterion("id not between", value1, value2, "id");
            return (Criteria) this;
        }

        public Criteria andNameIsNull() {
            addCriterion("name is null");
            return (Criteria) this;
        }

        public Criteria andNameIsNotNull() {
            addCriterion("name is not null");
            return (Criteria) this;
        }

        public Criteria andNameEqualTo(String value) {
            addCriterion("name =", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameNotEqualTo(String value) {
            addCriterion("name <>", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameGreaterThan(String value) {
            addCriterion("name >", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameGreaterThanOrEqualTo(String value) {
            addCriterion("name >=", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameLessThan(String value) {
            addCriterion("name <", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameLessThanOrEqualTo(String value) {
            addCriterion("name <=", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameLike(String value) {
            addCriterion("name like", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameNotLike(String value) {
            addCriterion("name not like", value, "name");
            return (Criteria) this;
        }

        public Criteria andNameIn(List<String> values) {
            addCriterion("name in", values, "name");
            return (Criteria) this;
        }

        public Criteria andNameNotIn(List<String> values) {
            addCriterion("name not in", values, "name");
            return (Criteria) this;
        }

        public Criteria andNameBetween(String value1, String value2) {
            addCriterion("name between", value1, value2, "name");
            return (Criteria) this;
        }

        public Criteria andNameNotBetween(String value1, String value2) {
            addCriterion("name not between", value1, value2, "name");
            return (Criteria) this;
        }
    }

    public static class Criteria extends GeneratedCriteria {

        protected Criteria() {
            super();
        }
    }

    public static class Criterion {
        private String condition;

        private Object value;

        private Object secondValue;

        private boolean noValue;

        private boolean singleValue;

        private boolean betweenValue;

        private boolean listValue;

        private String typeHandler;

        public String getCondition() {
            return condition;
        }

        public Object getValue() {
            return value;
        }

        public Object getSecondValue() {
            return secondValue;
        }

        public boolean isNoValue() {
            return noValue;
        }

        public boolean isSingleValue() {
            return singleValue;
        }

        public boolean isBetweenValue() {
            return betweenValue;
        }

        public boolean isListValue() {
            return listValue;
        }

        public String getTypeHandler() {
            return typeHandler;
        }

        protected Criterion(String condition) {
            super();
            this.condition = condition;
            this.typeHandler = null;
            this.noValue = true;
        }

        protected Criterion(String condition, Object value, String typeHandler) {
            super();
            this.condition = condition;
            this.value = value;
            this.typeHandler = typeHandler;
            if (value instanceof List<?>) {
                this.listValue = true;
            } else {
                this.singleValue = true;
            }
        }

        protected Criterion(String condition, Object value) {
            this(condition, value, null);
        }

        protected Criterion(String condition, Object value, Object secondValue, String typeHandler) {
            super();
            this.condition = condition;
            this.value = value;
            this.secondValue = secondValue;
            this.typeHandler = typeHandler;
            this.betweenValue = true;
        }

        protected Criterion(String condition, Object value, Object secondValue) {
            this(condition, value, secondValue, null);
        }
    }
}

mapper的java文件

package com.example.demo.mapper;

import com.example.demo.model.Student;
import com.example.demo.model.StudentExample;
import org.apache.ibatis.annotations.Param;

import java.util.List;

public interface StudentMapper {
    int countByExample(StudentExample example);

    int deleteByExample(StudentExample example);

    int deleteByPrimaryKey(String id);

    int insert(Student record);

    int insertSelective(Student record);

    List<Student> selectByExample(StudentExample example);

    Student selectByPrimaryKey(String id);

    int updateByExampleSelective(@Param("record") Student record, @Param("example") StudentExample example);

    int updateByExample(@Param("record") Student record, @Param("example") StudentExample example);

    int updateByPrimaryKeySelective(Student record);

    int updateByPrimaryKey(Student record);
}

mapper的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.example.demo.mapper.StudentMapper" >
  <resultMap id="BaseResultMap" type="com.example.demo.model.Student" >
    <id column="id" property="id" jdbcType="VARCHAR" />
    <result column="name" property="name" jdbcType="VARCHAR" />
  </resultMap>
  <sql id="Example_Where_Clause" >
    <where >
      <foreach collection="oredCriteria" item="criteria" separator="or" >
        <if test="criteria.valid" >
          <trim prefix="(" suffix=")" prefixOverrides="and" >
            <foreach collection="criteria.criteria" item="criterion" >
              <choose >
                <when test="criterion.noValue" >
                  and ${criterion.condition}
                </when>
                <when test="criterion.singleValue" >
                  and ${criterion.condition} #{criterion.value}
                </when>
                <when test="criterion.betweenValue" >
                  and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                </when>
                <when test="criterion.listValue" >
                  and ${criterion.condition}
                  <foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," >
                    #{listItem}
                  </foreach>
                </when>
              </choose>
            </foreach>
          </trim>
        </if>
      </foreach>
    </where>
  </sql>
  <sql id="Update_By_Example_Where_Clause" >
    <where >
      <foreach collection="example.oredCriteria" item="criteria" separator="or" >
        <if test="criteria.valid" >
          <trim prefix="(" suffix=")" prefixOverrides="and" >
            <foreach collection="criteria.criteria" item="criterion" >
              <choose >
                <when test="criterion.noValue" >
                  and ${criterion.condition}
                </when>
                <when test="criterion.singleValue" >
                  and ${criterion.condition} #{criterion.value}
                </when>
                <when test="criterion.betweenValue" >
                  and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                </when>
                <when test="criterion.listValue" >
                  and ${criterion.condition}
                  <foreach collection="criterion.value" item="listItem" open="(" close=")" separator="," >
                    #{listItem}
                  </foreach>
                </when>
              </choose>
            </foreach>
          </trim>
        </if>
      </foreach>
    </where>
  </sql>
  <sql id="Base_Column_List" >
    id, name
  </sql>
  <select id="selectByExample" resultMap="BaseResultMap" parameterType="com.example.demo.model.StudentExample" >
    select
    <if test="distinct" >
      distinct
    </if>
    'true' as QUERYID,
    <include refid="Base_Column_List" />
    from student
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
    <if test="orderByClause != null" >
      order by ${orderByClause}
    </if>
  </select>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.String" >
    select 
    <include refid="Base_Column_List" />
    from student
    where id = #{id,jdbcType=VARCHAR}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.String" >
    delete from student
    where id = #{id,jdbcType=VARCHAR}
  </delete>
  <delete id="deleteByExample" parameterType="com.example.demo.model.StudentExample" >
    delete from student
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
  </delete>
  <insert id="insert" parameterType="com.example.demo.model.Student" >
    insert into student (id, name)
    values (#{id,jdbcType=VARCHAR}, #{name,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.example.demo.model.Student" >
    insert into student
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        id,
      </if>
      <if test="name != null" >
        name,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        #{id,jdbcType=VARCHAR},
      </if>
      <if test="name != null" >
        #{name,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <select id="countByExample" parameterType="com.example.demo.model.StudentExample" resultType="java.lang.Integer" >
    select count(*) from student
    <if test="_parameter != null" >
      <include refid="Example_Where_Clause" />
    </if>
  </select>
  <update id="updateByExampleSelective" parameterType="map" >
    update student
    <set >
      <if test="record.id != null" >
        id = #{record.id,jdbcType=VARCHAR},
      </if>
      <if test="record.name != null" >
        name = #{record.name,jdbcType=VARCHAR},
      </if>
    </set>
    <if test="_parameter != null" >
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByExample" parameterType="map" >
    update student
    set id = #{record.id,jdbcType=VARCHAR},
      name = #{record.name,jdbcType=VARCHAR}
    <if test="_parameter != null" >
      <include refid="Update_By_Example_Where_Clause" />
    </if>
  </update>
  <update id="updateByPrimaryKeySelective" parameterType="com.example.demo.model.Student" >
    update student
    <set >
      <if test="name != null" >
        name = #{name,jdbcType=VARCHAR},
      </if>
    </set>
    where id = #{id,jdbcType=VARCHAR}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.example.demo.model.Student" >
    update student
    set name = #{name,jdbcType=VARCHAR}
    where id = #{id,jdbcType=VARCHAR}
  </update>
</mapper>

然后编写一个访问数据的controller和响应的service处理类

package com.example.demo.service;

import com.example.demo.model.Student;

public interface GetStudentService {

    public Student getStudentInfo();
}

package com.example.demo.service.impl;

import com.example.demo.mapper.StudentMapper;
import com.example.demo.model.Student;
import com.example.demo.service.GetStudentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class GetStudentServiceImpl implements GetStudentService {

    @Autowired
    private StudentMapper studentMapper;

    @Override
    public Student getStudentInfo() {
        Student student = studentMapper.selectByPrimaryKey("122528");
        return student;
    }
}

package com.example.demo.controller;

import com.example.demo.model.Student;
import com.example.demo.service.impl.GetStudentServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class GetStudentController {

    @Autowired
    private GetStudentServiceImpl getStudentServiceImpl;

    @RequestMapping("/getStudent")
    public String getStudent(){
        Student student = getStudentServiceImpl.getStudentInfo();
        return "学号=" + student.getId() + ";姓名=" + student.getName();
    }
}

最后修改一下启动类，用于扫描所有的mapper文件。

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

@SpringBootApplication
@MapperScan(basePackages = ("com.example.demo.mapper"))
public class DemoApplication extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(DemoApplication.class);
    }

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

运行效果如下：