spring+mybatis

整体结构

pom.xml

<?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>org.mythsky</groupId>
    <artifactId>spring-boot-mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

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

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.8-dmr</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/log4j/log4j -->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

log4j.properties

log4j.rootLogger=ERROR,stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://192.168.31.146:3306/mydb"/>
                <property name="username" value="root"/>
                <property name="password" value="password"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="UserMapper.xml"/>
    </mappers>
</configuration>

User

package org.mythsky.mybatis;

public class User {
    private Integer id;
    private String name;
    private Integer sex;
    private Integer age;

    public User(String name, Integer sex, Integer age) {
        this.name = name;
        this.sex = sex;
        this.age = age;
    }

    public Integer getId() {

        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getSex() {
        return sex;
    }

    public void setSex(Integer sex) {
        this.sex = sex;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

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="org.mythsky.mybatis">
    <insert id="save" parameterType="org.mythsky.mybatis.User" useGeneratedKeys="true">
        INSERT INTO person(name,sex,age) VALUES (#{name},#{sex},#{age})
    </insert>
</mapper>

这里需要注意的是Mapper上需要指定namespace

MyBatisTest

package org.mythsky.mybatis;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class MyBatisTest {
    public static void main(String[] args) throws IOException {
        InputStream inputStream= Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session=factory.openSession();
        User user=new User("admin",1,18);
        session.insert("save",user);
        session.commit();
        session.close();
    }
}

运行Test

查看数据库

 select

修改MybatisTest

InputStream inputStream= Resources.getResourceAsStream("mybatis-config.xml");
        SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session=factory.openSession();
        User user=session.selectOne("org.mythsky.mybatisdemo.domain.selectUser",1);
        System.out.println(user);
        session.commit();
        session.close();

修改UserMapper

<select id="selectUser" parameterType="int" resultType="org.mythsky.mybatisdemo.domain.User">
        SELECT * FROM  person WHERE id=#{id}
    </select>

此时运行会报错，因为User没有4个参数的构造函数，修改User，添加带id的构造函数

public User(Integer id, String name, Integer sex, Integer age) {
        this.id = id;
        this.name = name;
        this.sex = sex;
        this.age = age;
    }

再次运行即可

 update

UserMapper新增配置

<update id="updateUser" parameterType="org.mythsky.mybatisdemo.domain.User">
        UPDATE person SET name=#{name},sex=#{sex},age=#{age} WHERE id=#{id}
    </update>

Test代码更新

User user=session.selectOne("org.mythsky.mybatisdemo.domain.selectUser",1);
        user.setName("tom");
        session.update("org.mythsky.mybatisdemo.domain.updateUser",user);

运行后查看数据库

 delete

UserMapper更新

<delete id="deleteUser" parameterType="int">
        DELETE FROM person WHERE id=#{id}
    </delete>

测试更新

session.delete("org.mythsky.mybatisdemo.domain.deleteUser",2);

运行后查看数据库

 ResultMap

添加配置

<select id="selectUserMap" resultType="map">
        select * from person
    </select>

测试

List<Map<String,Object>> list=session.selectList("org.mythsky.mybatisdemo.domain.selectUserMap");
        for(Map<String,Object> row:list){
            System.out.println(row);
        }

结果

 添加两张表

CREATE table tb_clazz(id int PRIMARY KEY auto_increment,code varchar(18));
INSERT into tb_clazz(code) VALUES('c0001');
INSERT into tb_clazz(code) VALUES('c0002');
CREATE TABLE tb_student(id int PRIMARY KEY auto_increment,name varchar(18),sex char(3),age int,clazz_id int);
insert into tb_student(name,sex,age,clazz_id) values ('jack','男',22,1);
insert into tb_student(name,sex,age,clazz_id) values ('rose','女',18,1);
insert into tb_student(name,sex,age,clazz_id) values ('tom','男',25,2);
insert into tb_student(name,sex,age,clazz_id) values ('jerry','女',20,2);

Clazz

package org.mythsky.mybatisdemo.domain;

public class Clazz {
    private Integer id;
    private String code;

    public Integer getId() {
        return id;
    }

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

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }
}

Student

package org.mythsky.mybatisdemo.domain;

public class Student {
    private Integer id;
    private String name;
    private String sex;
    private Integer age;
    private Clazz clazz;

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Clazz getClazz() {
        return clazz;
    }

    public void setClazz(Clazz clazz) {
        this.clazz = clazz;
    }
}

UserMapper

<resultMap id="studentResultMap" type="org.mythsky.mybatisdemo.domain.Student">
        <id property="id" column="id"></id>
        <result property="name" column="name"></result>
        <result property="sex" column="sex"></result>
        <result property="age" column="age"></result>
        <association property="clazz" column="clazz_id"
                     javaType="org.mythsky.mybatisdemo.domain.Clazz"
                     select="selectClazzWithId"></association>
    </resultMap>
    <select id="selectClazzWithId" resultType="org.mythsky.mybatisdemo.domain.Clazz">
        select * from tb_clazz WHERE id=#{id};
    </select>
    <select id="selectStudent" resultMap="studentResultMap">
        select * from tb_student;
    </select>

Test

List<Student> list=session.selectList("org.mythsky.mybatisdemo.domain.selectStudent");
        for(Student student:list){
            System.out.println(student);
        }

运行

 更新Clazz

private List<Student> students;

    public List<Student> getStudents() {
        return students;
    }

    public void setStudents(List<Student> students) {
        this.students = students;
    }

更新mapper

<resultMap id="clazzResultMap" type="org.mythsky.mybatisdemo.domain.Clazz">
        <id property="id" column="id"></id>
        <result property="code" column="code"></result>
        <collection property="students" javaType="ArrayList" column="id" 
                    ofType="org.mythsky.mybatisdemo.domain.Student" select="selectStudentWithId"></collection>
    </resultMap>
    <select id="selectStudentWithId" resultType="org.mythsky.mybatisdemo.domain.Student">
        SELECT * from tb_student where clazz_id=#{id}
    </select>
    <select id="selectClazz" resultMap="clazzResultMap">
        select * from tb_clazz;
    </select>

更新测试

List<Clazz> list=session.selectList("org.mythsky.mybatisdemo.domain.selectClazz");
        for(Clazz clazz:list){
            System.out.println(clazz);
            List<Student> students=clazz.getStudents();
            for(Student student:students){
                System.out.println(student.getId()+" "+student.getName()+" "+student.getSex()+" "+student.getAge());
            }
        }

运行结果