spring boot2 整合（一）Mybatis （特别完整！

作者: FantJ | 来源:发表于2018-03-09 22:13 被阅读759次

整合Mybatis分为两种模式，一种是xml配置，一种是注解。（类似JPA）
我在这里重点放在xml配置上，因为如果想用注解的话，建议直接用jpa代替，因为Jpa有更成熟的CRUD接口更方便开发。我在后文中也会把注解方式说清楚。

大概介绍下流程：

借助idea实现mybatis逆向工程
用xml配置实现整合
用cmd命令行实现mybatis逆向工程
用mapping.xml配置实现数据交互
用注解的方式实现数据交互

首先我的开发环境：
jdk1.8+maven3+IDEA

1. mybatis逆向攻城

逆向工程方式很多，我目前接触到的就两种，一种是借助于ide开发工具，一种是在cmd中执行命令。（其实二者原理都一样，都是执行maven的generator命令，具体请看下文）。

1. 完善pom文件

<?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>

    <groupId>springboot-mybatis</groupId>
    <artifactId>springboot-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springboot-mybatis</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>springboot-integration</groupId>
        <artifactId>springboot-integration</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <!-- Add typical dependencies for a web application -->
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <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>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.35</version>
        </dependency>
        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.11</version>
        </dependency>
        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.0</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>5.0.4</version>
        </dependency>
    </dependencies>

    <!-- Package as an executable jar -->
    <build>
        <finalName>springboot-mybatis</finalName>
        <plugins>
            <plugin>

                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <configuration>
                    <testFailureIgnore>true</testFailureIgnore>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.2</version>
                <configuration>
                    <verbose>true</verbose>
                    <overwrite>true</overwrite>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

2. 逆向所需配置文件generatorConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
    <classPathEntry  location="E:\lib\mysql_driver\mysql-connector-java-5.1.26-bin.jar"/>
    <context id="DB2Tables"  targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库链接URL，用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1/user" userId="root" password="root">
        </jdbcConnection>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!-- 生成模型的包名和位置-->
        <javaModelGenerator targetPackage="com.fantj.sbmybatis.model" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!-- 生成映射文件的包名和位置-->
        <sqlMapGenerator targetPackage="mapping" targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!-- 生成DAO的包名和位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.fantj.sbmybatis.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
        <table tableName="user" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
    </context>
</generatorConfiguration>

3. 利用IDE创建逆向工程启动类

4. add一个Maven configuration

5. 我的数据库和表结构

6. application配置文件

server:
  port: 8080

spring:
  datasource:
    name: test
    url: jdbc:mysql://127.0.0.1:3306/user
    username: root
    password: root
    # druid 连接池
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.jdbc.Driver
    filters: stat
    maxActive: 20
    initialSize: 1
    maxWait: 60000
    minIdle: 1
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: select 'x'
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    maxOpenPreparedStatements: 20

mybatis:
  mapper-locations: classpath:mapping/*.xml
  type-aliases-package: com.fant.model

#pagehelper分页插件
pagehelper:
    helperDialect: mysql
    reasonable: true
    supportMethodsArguments: true
    params: count=countSql

运行generator工程自动生成代码

生成的文件

User.java

package com.fantj.model;

import java.util.Date;

public class User {
    private Integer id;

    private String username;

    private Date birthday;

    private String sex;

    private String address;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username == null ? null : username.trim();
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex == null ? null : sex.trim();
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address == null ? null : address.trim();
    }
}

UserMapper .java

package com.fantj.mapper;

import com.fantj.model.User;

import java.util.List;

public interface UserMapper {
    int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);

    List<User> selectAll();
}

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="com.fantj.mapper.UserMapper" >
  <resultMap id="BaseResultMap" type="com.fantj.model.User" >
    <id column="id" property="id" jdbcType="INTEGER" />
    <result column="username" property="username" jdbcType="VARCHAR" />
    <result column="birthday" property="birthday" jdbcType="DATE" />
    <result column="sex" property="sex" jdbcType="CHAR" />
    <result column="address" property="address" jdbcType="VARCHAR" />
  </resultMap>
  <sql id="Base_Column_List" >
    id, username, birthday, sex, address
  </sql>
  <select id="selectAll" resultMap="BaseResultMap" >
    select
    <include refid="Base_Column_List" />
    from user
  </select>
  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from user
    where id = #{id,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from user
    where id = #{id,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="com.fantj.model.User" >
    insert into user (id, username, birthday, 
      sex, address)
    values (#{id,jdbcType=INTEGER}, #{username,jdbcType=VARCHAR}, #{birthday,jdbcType=DATE}, 
      #{sex,jdbcType=CHAR}, #{address,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.fantj.model.User" >
    insert into user
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        id,
      </if>
      <if test="username != null" >
        username,
      </if>
      <if test="birthday != null" >
        birthday,
      </if>
      <if test="sex != null" >
        sex,
      </if>
      <if test="address != null" >
        address,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="id != null" >
        #{id,jdbcType=INTEGER},
      </if>
      <if test="username != null" >
        #{username,jdbcType=VARCHAR},
      </if>
      <if test="birthday != null" >
        #{birthday,jdbcType=DATE},
      </if>
      <if test="sex != null" >
        #{sex,jdbcType=CHAR},
      </if>
      <if test="address != null" >
        #{address,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.fantj.model.User" >
    update user
    <set >
      <if test="username != null" >
        username = #{username,jdbcType=VARCHAR},
      </if>
      <if test="birthday != null" >
        birthday = #{birthday,jdbcType=DATE},
      </if>
      <if test="sex != null" >
        sex = #{sex,jdbcType=CHAR},
      </if>
      <if test="address != null" >
        address = #{address,jdbcType=VARCHAR},
      </if>
    </set>
    where id = #{id,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.fantj.model.User" >
    update user
    set username = #{username,jdbcType=VARCHAR},
      birthday = #{birthday,jdbcType=DATE},
      sex = #{sex,jdbcType=CHAR},
      address = #{address,jdbcType=VARCHAR}
    where id = #{id,jdbcType=INTEGER}
  </update>
</mapper>

修改启动类

逆向生成代码后，我们还需要在启动类上添加一个@MapperScan("com.fantj.mapper")注解，告诉我们的Mapper需要扫描的包，这样就不用每个Mapper上都添加@Mapper注解了。

@SpringBootApplication
@MapperScan("com.fantj.mapper")
public class MybatisApplication {

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

}

完善controller和service

UserController.java

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping(method = RequestMethod.GET,value = "/delete/{id}")
    public void delete(@PathVariable("id")int id){
        userService.delete(id);
    }

    @RequestMapping(method = RequestMethod.POST,value = "/insert")
    public void insert(User user){
        userService.insert(user);
    }
    @RequestMapping(method = RequestMethod.POST,value = "/update/{id}")
    public void update(@RequestParam User user){
        userService.update(user);
    }

    @RequestMapping(method = RequestMethod.GET,value = "/{id}/select")
    public User select(@PathVariable("id")int id){
        return userService.selectById(id);
    }

    @RequestMapping(method = RequestMethod.GET,value = "/selectAll/{pageNum}/{pageSize}")
    public List<User> selectAll(@PathVariable("pageNum") int pageNum, @PathVariable("pageSize") int pageSize){
        return userService.selectAll(pageNum,pageSize);
    }

}

UserService.java

package com.fantj.service;

import com.fantj.model.User;

import java.util.List;

public interface UserService {
    /** 删除 */
    public void delete(int id);
    /** 增加*/
    public void insert(User user);
    /** 更新*/
    public int update(User user);
    /** 查询单个*/
    public User selectById(int id);
    /** 查询全部列表*/
    public List<User> selectAll(int pageNum, int pageSize);
}

UserServiceImpl .java

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    /**
     * 删除
     *
     * @param id
     */
    @Override
    public void delete(int id) {
        userMapper.deleteByPrimaryKey(id);
    }

    /**
     * 增加
     *
     * @param user
     */
    @Override
    public void insert(User user) {
        userMapper.insert(user);
    }

    /**
     * 更新
     *
     * @param user
     */
    @Override
    public int update(User user) {
        return userMapper.updateByPrimaryKey(user);
    }

    /**
     * 查询单个
     *
     * @param id
     */
    @Override
    public User selectById(int id) {
        return userMapper.selectByPrimaryKey(id);
    }

    /**
     * 查询全部列表,并做分页
     *
     * @param pageNum 开始页数
     * @param pageSize 每页显示的数据条数
     */
    @Override
    public List<User> selectAll(int pageNum, int pageSize) {
        //将参数传给这个方法就可以实现物理分页了，非常简单。
        PageHelper.startPage(pageNum,pageSize);
        return userMapper.selectAll();
    }
}

浏览器访问127.0.0.1/user/selectAll/0/1

说明我们成功了。

一个小甜点

有人问，get方法可以直接从浏览器地址中的url来测试，那post请求怎么测试呢？
个人建议用postman工具，也可以写测试类用代码来完成测试。也可以使用idea的一个测试工具Test RESTful Web Service

注解方式

好了，配置方式我们介绍完了，我在这里稍微聊一聊注解开发方式，个人建议如果想用注解开发，直接用jpa，可以更方便自己的开发。

mybatis java api ：http://www.mybatis.org/mybatis-3/zh/java-api.html

UserMapper.java

package com.fantj.mapper;

import com.fantj.model.User;
import org.apache.ibatis.annotations.*;

import java.util.List;

public interface UserMapper {
    /*int deleteByPrimaryKey(Integer id);

    int insert(User record);

    int insertSelective(User record);

    User selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(User record);

    int updateByPrimaryKey(User record);

    List<User> selectAll();*/
    //如果实例对象中的属性名和数据表中字段名不一致，用@Result注解进行说明映射关系，我在这里只是告诉你怎么写
    @Select("SELECT * FROM user")
    @Results({
            @Result(property = "username", column = "username"),
            @Result(property = "sex",  column = "sex"),
            @Result(property = "address",column = "address")
    })
    List<User> selectAll();

    @Select("SELECT * FROM user WHERE id = #{id}")
    @Results({
            @Result(property = "sex",  column = "sex"),
            @Result(property = "username", column = "username")
    })
    User selectByPrimaryKey(int id);

    @Insert({"INSERT INTO user(username,birthday,sex,address}) VALUES(#{userName}, #{birthday}, #{sex},#{address})"})
    void insert(User user);

    @Update("UPDATE user SET userName=#{userName} WHERE id =#{id}")
    int updateByPrimaryKey(User user);

    @Delete("DELETE FROM user WHERE id =#{id}")
    int deleteByPrimaryKey(int id);
}

注解的一些解释

@Select 是查询类的注解，所有的查询均使用这个
@Result 修饰返回的结果集，关联实体类属性和数据库字段一一对应，如果实体类* 属性和数据库属性名保持一致，就不需要这个属性来修饰。
@Insert 插入数据库使用，直接传入实体类会自动解析属性到对应的值
@Update 负责修改，也可以直接传入对象
@delete 负责删除

注意将application配置文件中的mybatis.mapper-locations:属性注视掉再启动项目。否则它会报错：Mapped Statements collection already contains value for com.fantj.mapper.UserMapper.insert 。意思是mapper中方法重复。

最后一个甜点

还有一个东西忘说了 -.-,就是用cmd来逆向生成代码。

声称语句

java -jar mybatis-generator-core-1.3.2.jar -configfile generator.xml -overwrite
src目录请忽略，这是生成的目录。
好了干货都分享了，谢谢大家。0.0

spring boot2 整合（一）Mybatis （特别完整！

1. mybatis逆向攻城

1. 完善pom文件

2. 逆向所需配置文件generatorConfig.xml

3. 利用IDE创建逆向工程启动类

4. add一个Maven configuration

5. 我的数据库和表结构

6. application配置文件

生成的文件

User.java

UserMapper .java

UserMapper.xml

修改启动类

完善controller和service

UserController.java

UserService.java

UserServiceImpl .java

浏览器访问127.0.0.1/user/selectAll/0/1

一个小甜点

注解方式

mybatis java api ：http://www.mybatis.org/mybatis-3/zh/java-api.html

UserMapper.java

注解的一些解释

注意将application配置文件中的mybatis.mapper-locations:属性注视掉再启动项目。否则它会报错：Mapped Statements collection already contains value for com.fantj.mapper.UserMapper.insert 。意思是mapper中方法重复。

最后一个甜点

声称语句

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