mybatis- entry project (maven)

.1 create maven project, adding a dependency in 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>com.cong</groupId>
    <artifactId>mybatics_firstDemo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <packaging>jar</packaging>
    <dependencies>
        <!-- mybatis核心包-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <!-- mysql驱动包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.29</version>
        </dependency>
        <!-- junit测试包 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>
    </dependencies>
</project>

2.mysql database-related actions

 

3 .. Creating com.cong.pojo.Account class in the java directory

package com.cong.pojo;

public class Account {
    private int id;
    private String name;
    private float money;

    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 float getMoney() {
        return money;
    }

    public void setMoney(float money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}

4. Create mybatis-context.xml file in the resources directory

<? xml Version = "1.0" encoding = "UTF-8"?> 
<! DOCTYPE the Configuration 
        the PUBLIC "- // mybatis.org//DTD Config 3.0 // EN" 
        "http://mybatis.org/dtd/mybatis config.dtd--3 "> 
<the configuration> 
    <-! environment configuration -> 
    <typeAliases> 
        <-! namespaces, so AccountMapper return value would not write com.cong.pojo.Account, just write Account it -> 
        < Package name = "com.cong.pojo"> </ Package > 
    </ typeAliases> 
    <Environments default = "Development"> 
        <Environment ID = "Development"> 
            <transactionManager type="JDBC"/>type = the transactionManager "the JDBC" /> 
            <-! database connection configuration, dynamically acquires the content file config.properties here ->
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/cong" />
                <property name="username" value="root" />
                <property name="password" value="123456" />
            </dataSource>
        </environment>
    </environments>
    <!-- mapping文件路径配置 -->
    <mappers>
        <mapper resource="mapper/AccountMapper.xml"/>
    </mappers>
</configuration>

5. Create mapper directory in the resources directory, create accountMapper.xml file in the directory mapper

<? xml Version = "1.0" encoding = "UTF-8"?> 
<! DOCTYPE Mapper 
        the PUBLIC "- // mybatis.org//DTD Mapper 3.0 // EN" 
        "http://mybatis.org/dtd/mybatis mapper.dtd--3 "> 

    <-! 
    Mapper root node mapping, namespace specified interface Dao full class name 
    mybatis dynamically creates a basis for this interface implementation class to implement this interface, 
    and this class is to achieve a target Mapper
     -> 
<Mapper namespace = "com.cong.pojo.Account"> 
    <SELECT ID = "the findAll" the resultType = "the Account"> 
        SELECT * from Account
     </ SELECT> 
    <SELECT ID = "the findById" the parameterType = "int" resultType = "Account">
        select * from account where id = #{id}
    </select>
</mapper>

6. Create AccountTest test class under test, java directory

import com.cong.pojo.Account;
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.Reader;
import java.util.List;

public class AccountTest {

    @Test
    public void accountFindById(){
        SqlSession session = getSqlSession();
        //传入参数查询，返回结果
        Account account=session.selectOne("findById",1);
        //输出结果
        System.out.println(account.toString());
        //关闭session
        session.close();
    }
    @Test
    public void accountFindAll(){
        SqlSession session = getSqlSession();
        List<Account> list = session.selectList("findAll");
        for (Account account : list) {
            System.out.println(account.toString());
        }
        session.close();
    }
    private SqlSession getSqlSession() {
        //Read file names defined 
        String Resources = "mybatis-config.xml" ;
         // Create stream 
        Reader reader = null ;
         the try {
             // read mybatis-config.xml file reader to the object 
            reader = Resources.getResourceAsReader (Resources); 
        } the catch (IOException E) { 
            e.printStackTrace (); 
        } 
        // initialize mybatis, create an instance of the class SqlSessionFactory 
        SqlSessionFactory sqlMapper = new new the SqlSessionFactoryBuilder () Build (Reader);.
         // create a session instance 
        return sqlMapper.openSession (); 
    }
}

7.findAll unit test results

8. The full directory structure