Mybatis入门1

开发环境：

Java JDK11,Maven,IntelliJ Idea,MySQL.

1. 先建立pom.xml文件，导入所需的依赖。

<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>com.oxygen</groupId>
    <artifactId>projectMybatis</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>projectMybatis</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.complier.target>11</maven.complier.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.10</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.30</version>
        </dependency>

        <dependency>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.10.1</version>
        </dependency>

    </dependencies>

    <build>

        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                    <include>**/resources/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
                <filtering>false</filtering>
            </resource>
        </resources>
        <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.10.1</version>
            <configuration>
                <source>11</source>
                <target>11</target>
            </configuration>
        </plugin>
        </plugins>
    </build>
</project>

 

在此Resources目录下建立Mybatis的主配置文件:mybatis-config.xml

src/main/resources/MybatisConfig.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://192.168.3.12:3306/oxygen"/>
                <property name="username" value="root"/>
                <property name="password" value="abcd2022"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/oxygen/dao/StudentDao.xml"/>
    </mappers>
</configuration>

 

在此目录下建立mapper文件。mapper文件就是一个有SQL语句的SQL文件。

src/main/java/com/oxygen/dao/StudentDao.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.oxygen.dao.StudentDao">
    <select id="selectStudentsAll" resultType="com.oxygen.entity.Student">
        select * from oxygen.student
    </select>
    <insert id="insertStudent">
        insert into oxygen.student values(#{id},#{name},#{age},#{email})
    </insert>
</mapper>

 

在此目录建立dao的Java接口

src/main/java/com/oxygen/dao/StudentDao.java

package com.oxygen.dao;

import com.oxygen.entity.Student;

import java.util.List;

public interface StudentDao {

    public List<Student> selectStudentsAll();

    public int insertStudent(Student student);
}

 

建立Java的实体类

src/main/java/com/oxygen/entity/Student.java

package com.oxygen.entity;

public class Student {
    private int id;
    private String name;
    private int age;
    private String email;

    public int getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "Student{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                ", email='" + email + '\'' +
                '}';
    }
}

 

测试类

src/test/java/TestDB.java

import com.oxygen.entity.Student;
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 org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class TestDB {

    @Test
    public void testSearchDB() throws IOException {
        String config="MybatisConfig.xml";
        InputStream in=Resources.getResourceAsStream(config);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(in);
        SqlSession session =sqlSessionFactory.openSession();
//        List<Student> result=session.selectList("com.oxygen.dao.StudentDao.selectStudentsAll");
//        result.forEach(System.out::println);
        String sql="com.oxygen.dao.StudentDao.insertStudent";
        Student student=new Student();
        student.setEmail("tianyu@utopaschool.com");
        student.setId(1008);
        student.setAge(19);
        student.setName("田雨");
        int num=session.insert(sql,student);
        session.commit();
        System.out.println("Inert Result:"+num);
        session.close();
    }
}