搭建框架

建立maven项目就不说了

导入需要用到的依赖

<dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
  <version>4.11</version>
  <scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>3.4.6</version>
</dependency>
?
<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.47</version>
</dependency>

由于怕maven资源导出失败，需要在pom.xml的build里边加入这段话

<resources>
  <resource>
    <directory>src/main/resources</directory>
    <includes>
      <include>**/*.properties</include>
      <include>**/*.xml</include>
    </includes>
  </resource>
  <resource>
    <directory>src/main/java</directory>
    <includes>
      <include>**/*.properties</include>
      <include>**/*.xml</include>
    </includes>
    <filtering>true</filtering>
  </resource>
</resources>

先在resources创建my-batis-config.xml 声明数据库配置信息

<?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"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://127.0.0.1:3306/student?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value=""/>
                <property name="password" value=""/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/**/dao/UserMapper.xml"/>
    </mappers>
</configuration>

依然是先创建实体类，例子：

package com.lt.pojo;
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public class User {
    public User() {
    }
?
    private int id;
?
    public int getId() {
        return id;
    }
?
    public void setId(int id) {
        this.id = id;
    }
?
    public String getUserName() {
        return userName;
    }
?
    public void setUserName(String userName) {
        this.userName = userName;
    }
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    public String getPassword() {
        return password;
    }
?
    public void setPassword(String password) {
        this.password = password;
    }
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    public User(int id, String userName, String password) {
        this.id = id;
        this.userName = userName;
        this.password = password;
    }
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    private String userName;
    private String password;
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    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", userName=‘" + userName + ‘\‘‘ +
                ", password=‘" + password + ‘\‘‘ +
                ‘}‘;
    }
}

创建工具类MyBatisUtil

package com.lt.util;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
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import java.io.InputStream;
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public class MybatisUtil {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            String resource = "mybatis-config.xml";
            InputStream inputStream = Resources.getResourceAsStream(resource);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

增删改查的例子

依然是创建一个dao包，我的名字是UserMapper

package com.lt.dao;
?
import com.lt.pojo.User;
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import java.util.List;
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public interface UserMapper {
    List<User> getUserList();    //泛型是User，得到列表
    User getuserByid(int id);       //返回类型是User      查
    int addUser(User user);         //返回类型是int       增
    int upDate(User user);          //返回类型是int       改
    int deletDate(int id);          //返回类型是int       删
}

普通项目该写实现类了，但是我们是mybatis欸！所以直接写一个xml文件对应方法。名字是UserMapper.xml,对应在resource里边的mapper

<?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.lt.dao.UserMapper">
    <select id="getUserList" resultType="com.lt.pojo.User">
select * from user
</select>
    <select id="getuserByid" resultType="com.lt.pojo.User" parameterType="int">
select * from user where id=#{id}
</select>
?
    <insert id="addUser" parameterType="com.lt.pojo.User" >
insert into user (id,userName,password) values(#{id},#{userName},#{password})
    </insert>
?
    <update id="upDate" parameterType="com.lt.pojo.User">
        update user set userName=#{userName},password=#{password} where id=#{id};
    </update>
    <delete id="deletDate" parameterType="int">
        delete from user where id=#{id};
    </delete>
</mapper>

接下来测试看我们的功能是否有效

切记！增删改返回类型都是int，查返回类型是user

增删改都要commit（）一下

@Test
public void test(){
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    List<User> userList = mapper.getUserList();
    for (User user : userList) {
        System.out.println(user);
    }
    sqlSession.close();
}
?
@Test
public void test1(){
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    User user = mapper.getuserByid(2);
    System.out.println(user);
    sqlSession.close();
}
@Test
public void test2() {
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    int lt = mapper.addUser(new User(3,"lt","123"));
    if (lt>0){
        System.out.println("111111111111");
    }
    sqlSession.commit();
    sqlSession.close();
}
@Test
public void test3(){
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    int ltt = mapper.upDate(new User(3, "ltt", "123123"));
    sqlSession.commit();
    sqlSession.close();
}
@Test
public void test4(){
    SqlSession sqlSession = MybatisUtil.getSqlSession();
    UserMapper mapper = sqlSession.getMapper(UserMapper.class);
    int i = mapper.deletDate(2);
    sqlSession.commit();
    sqlSession.close();
}

 还有mybatis的文档要的留言

mybatis测试做到简单的增删改查

原文：https://www.cnblogs.com/ltdh/p/12496666.html