mybatis基本專案搭建

阿新 • • 發佈：2020-09-08

第一步.新建資料庫，匯入依賴

1.新建資料庫表,user

2.匯入依賴

 <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.5</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.12</version>
        </dependency>

第二步.新建pojo實體類，user類

//新建使用者實體類user
package pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private Integer userId;
    private String userName;
    private String userEmail;
    private Integer countryId;
 
    private Integer depId;
    private Integer version;
    private Integer deleted;
}

第三步:.新建mapper類和xml檔案

//使用者類介面 userMapper
package mapper;
import pojo.User;
import java.util.List;
import java.util.Map;
public interface UserMapper {
    public List<User> getUserList();
    public List<User> getUserList2();
     
public User getUser(Integer id);
    public Integer addUser(User user);
    public Integer addUser2(Map<String,Object> map);
    public void updateUser(User user);
    public void deleteUser(Integer id);

}

//使用者介面的xml檔案 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">
<!--繫結一個操作資料庫的介面-->
<mapper namespace="mapper.UserMapper">
    <!--查詢    -->
    <!--本來這裡的resultType要寫全限定類名，但是在mybaits-config.xml檔案中配置了別名user後，這裡可以直接寫user-->
    <select id="getUserList" resultType="user">
        select * from user
    </select>

    <!--使用resultmap 解決實體類和資料庫欄位不一致的問題，這裡我故意把實體類的email 改為userEmail   -->
    <resultMap id="userMap" type="user">
        <!-- column是資料庫中的欄位名，  property是實體類的屬性     -->
        <result column="email" property="userEmail"></result>
    </resultMap>
    <select id="getUserList2" resultMap="userMap">
        select * from user
    </select>


    <select id="getUser" parameterType="Integer" resultType="user">
        select * from user where userId=#{id}
    </select>

<!--    parameterTypes 是一個實體類，那麼sql 語句裡面的引數必須和實體類的屬性一致-->
    <insert id="addUser" parameterType="user" >
        insert into user (userId,userName) values(#{userId},#{userName})
    </insert>
<!--    //parameterTypes 是一個hashmap，那麼sql 語句裡面的引數不用和實體類的屬性一致-->
    <insert id="addUser2" parameterType="map" >
        insert into user (userId,userName) values(#{uId},#{uName})
    </insert>

    <update id="updateUser" parameterType="pojo.User">
        update user set userName=#{userName},email=#{email} where userId=#{userId}
    </update>

    <delete id="deleteUser" parameterType="Integer">
        delete from  user where userId=#{userId}
    </delete>
</mapper>

第四步:新建連線的工具類

package myUntil;

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 MybatisUntil {
    private static SqlSessionFactory sqlSessionFactory;

    static {

        try {
            //使用mybatis 第一步，獲取sqlSessionFactory物件，這個物件時生成sqlSession的
            String resource= "mybatis-config.xml";
            InputStream inputStream= Resources.getResourceAsStream(resource);
            sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    //有了sqlSessionFactory，我們既可以用sqlSessionFactory來open 一個個的sqlSession
    //sqlSession是可以操作資料庫，他包含了所有的sql 語句操作
    public static SqlSession getSqlSession(){
        return  sqlSessionFactory.openSession();
    }
}

第五步:新建mybatis 的核心配置檔案

<?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>
    <!-- 配置日誌檔案   -->
    <settings>
<!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
        <setting name="logImpl" value="log4j"/>
<!--    開啟駝峰命名    -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    </settings>
<!--    <properties resource="db.properties"/>-->
    <!--別名    -->
    <typeAliases>
<!--        &lt;!&ndash;設定User類的別名為user        &ndash;&gt;-->
<!--        <typeAlias type="pojo.User" alias="user"></typeAlias>-->
<!--        設定pojo包下的所有實體類的別名為類名的首字母小寫  -->
        <package name="pojo"/>
    </typeAliases>

    <environments default="develoment">
        <environment id="develoment">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://47.112.227.192:3306/spring?useUnicode=true&amp;characterEncoding=utf-8&amp;useSSL=false&amp;serverTimezone=GMT%2B8"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>

    <!--每一個mapper 都要在mybatis 的核心配置檔案中註冊    -->
    <mappers >
<!--        用resource對映的話就用全路徑-->
        <mapper resource="mapper/studentMapper.xml"></mapper>
<!--        <mapper resource="mapper/studentMapper.xml"></mapper>-->
<!--    用class 對映的話，要用介面的類的全限定類名    -->
<!--        <mapper class="mapper.StudentMapper"></mapper>-->
        <mapper resource="mapper/teacherMapper.xml"></mapper>
    </mappers>
</configuration>

第六步:新建log4j.properties檔案

### 設定###
log4j.rootLogger = debug,console,file

### 輸出資訊到控制抬 ###
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.Target = System.out
log4j.appender.console.Threshold = DEBUG 
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n

### 輸出DEBUG 級別以上的日誌到=E://logs/error.log ###
log4j.appender.file = org.apache.log4j.DailyRollingFileAppender
log4j.appender.file.File = ./logs/log.log
log4j.appender.file.Append = true
log4j.appender.file.MaxFilesSize=10mb
log4j.appender.file.Threshold = DEBUG 
log4j.appender.file.layout = org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

### 日誌輸出級別 ###
log4j.logger.org.mybatis =debug
log4j.logger.java.sql =debug
log4j.logger.java.sql.Statement =debug
log4j.logger.java.sql.ResultSet =debug
log4j.logger.java.sql.Preparedstatement =debug

第七步:新建測試

package test;

import com.sun.istack.internal.logging.Logger;
import mapper.UserMapper;
import myUntil.MybatisUntil;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;
import pojo.User;

import java.util.HashMap;
import java.util.List;

public class Mytest {
     static Logger logger=Logger.getLogger(UserMapper.class);

    //查詢所有使用者的方法
    @Test
    public void getUserList(){

        //通過我們自己編寫的工具類獲取sqlSession物件
        SqlSession sqlSession=MybatisUntil.getSqlSession();
        //通過getMapper獲取介面
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);

        List<User> userList = userMapper.getUserList();
        for (User user : userList) {
            System.out.println(user);
        }
        //這裡記得關閉，不然會造成資源浪費
        sqlSession.close();
    }
    //查詢所有使用者的方法,實體類把email改為userEmail,然後在xml 加resultMap
    @Test
    public void getUserList2(){
        //通過logger 輸出日誌
        logger.info("進入了這個方法");
        //通過我們自己編寫的工具類獲取sqlSession物件
        SqlSession sqlSession=MybatisUntil.getSqlSession();
        //通過getMapper獲取介面
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);

        List<User> userList = userMapper.getUserList2();
        for (User user : userList) {
            System.out.println(user);
        }
        //這裡記得關閉，不然會造成資源浪費
        sqlSession.close();
    }



    //查詢單個使用者的方法
    @Test
    public void getUser(){
        //通過我們自己編寫的工具類獲取sqlSession物件
        SqlSession sqlSession=MybatisUntil.getSqlSession();
        //通過getMapper獲取介面
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);

        User user=userMapper.getUser(1);
        System.out.println("user:"+user);

        sqlSession.close();
    }

    //新增使用者的方法(引數用實體類，這樣的話，xml裡面的欄位必須和實體類的欄位一致)
    @Test
    public void addUser(){
        //通過我們自己編寫的工具類獲取sqlSession物件
        SqlSession sqlSession=MybatisUntil.getSqlSession();
        //通過getMapper獲取介面
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);

        User user=new User();
        user.setUserId(10);
        user.setUserName("甚平");
        userMapper.addUser(user);
        System.out.println("加入使用者成功");
        //提交事務,低版本不會自動提交事務
        sqlSession.commit();
        sqlSession.close();
    }


    //新增使用者的方法(引數用map類，這樣的話，xml裡面的欄位不用和實體類的欄位一致)
    @Test
    public void addUser2(){
        //通過我們自己編寫的工具類獲取sqlSession物件
        SqlSession sqlSession=MybatisUntil.getSqlSession();
        //通過getMapper獲取介面
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);

        HashMap<String,Object> hashMap=new HashMap<String, Object>();
        hashMap.put("uId",20);
        hashMap.put("uName","四皇凱多");
        userMapper.addUser2(hashMap);

        System.out.println("加入使用者成功");
        //提交事務,低版本不會自動提交事務
        sqlSession.commit();
        sqlSession.close();
    }

    //更新使用者的方法
    @Test
    public void updateUser(){
        //通過我們自己編寫的工具類獲取sqlSession物件
        SqlSession sqlSession=MybatisUntil.getSqlSession();
        //通過getMapper獲取介面
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);

        User user=new User();
        user.setUserId(10);
        user.setUserName("海俠甚平22222");
        user.setUserEmail("[email protected]");
        userMapper.updateUser(user);
        System.out.println("更新成功");

    }

    //刪除使用者的方法
    @Test
    public void deleteUser(){
        //通過我們自己編寫的工具類獲取sqlSession物件
        SqlSession sqlSession=MybatisUntil.getSqlSession();
        //通過getMapper獲取介面
        UserMapper userMapper=sqlSession.getMapper(UserMapper.class);
        userMapper.deleteUser(2);
        System.out.println("刪除成功");

        sqlSession.commit();
        sqlSession.close();
    }

}