mybatis入门

搭建mybatis框架环境

1、创建maven工程

2、导入相关pom依赖

3、Mybatis相关插件安装

4、Mybatis.cfg.xml配置

pom.xml:

<properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <dependencies>
        <!-- ********************** junit单元测试依赖 ********************** -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <!-- ********************** Java Servlet API  ********************** -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.0</version>
            <scope>provided</scope>
        </dependency>

        <!-- ********************** Mybatis依赖 ********************** -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>

        <!-- ********************** Mysql JDBC驱动 ********************** -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.44</version>
        </dependency>

        <!-- **********************  日志配置  ********************** -->
        <!--记得修改mybatis.cfg.xml添加如下内容-->
        <!--<setting name="logImpl" value="LOG4J2"/>-->
        <!--核心log4j2jar包-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.9.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.9.1</version>
        </dependency>
        <!--web工程需要包含log4j-web，非web工程不需要-->
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-web</artifactId>
            <version>2.9.1</version>
        </dependency>
</dependencies>


 <build>
        <resources>
            <!--解决mybatis-generator-maven-plugin运行时没有将XxxMapper.xml文件放入target文件夹的问题-->
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
            <!--解决mybatis-generator-maven-plugin运行时没有将jdbc.properites文件放入target文件夹的问题-->
            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>jdbc.properties</include>
                    <include>*.xml</include>
                </includes>
            </resource>
        </resources>

        <plugins>
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.2</version>
                <dependencies>
                    <!--使用Mybatis-generator插件不能使用太高版本的mysql驱动 -->
                    <dependency>
                        <groupId>mysql</groupId>
                        <artifactId>mysql-connector-java</artifactId>
                        <version>5.1.44</version>
                    </dependency>
                </dependencies>
                <configuration>
                    <overwrite>true</overwrite>
                </configuration>
            </plugin>
        </plugins>

    </build>

　　Jdbc.properties

 

 

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=123

　　web.xml修改至3.1

 

接下来安装以下插件：

Free mybatis plugin

Mybatis generator

mybatis tools

maven helper 

插件详细介绍：

https://blog.csdn.net/yangshijin1988/article/details/63258960/

Mybatis.cfg.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>
    <!-- 引入外部配置文件 -->
    <properties resource="jdbc.properties"/>

    <settings>
        <setting name="logImpl" value="LOG4J2"/>
    </settings>

    <!-- 别名 -->
    <typeAliases>
        <!--<typeAlias type="com.javaxl.model.Book" alias="Book"/>-->
    </typeAliases>


    <!-- 配置mybatis运行环境 -->
    <environments default="development">
        <environment id="development">
            <!-- type="JDBC" 代表使用JDBC的提交和回滚来管理事务 -->
            <transactionManager type="jdbc"/>

            <!-- mybatis提供了3种数据源类型，分别是：POOLED,UNPOOLED,JNDI -->
            <!-- POOLED 表示支持JDBC数据源连接池 -->
            <!-- UNPOOLED 表示不支持数据源连接池 -->
            <!-- JNDI 表示支持外部数据源连接池 -->
            <dataSource type="POOLED">
                <property name="driver"
                          value="${jdbc.driver}"/>
                <property name="url"
                          value="${jdbc.url}"/>
                <property name="username" value="${jdbc.username}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>

    <mappers>
        <mapper resource="com/javaxl/mapper/BookMapper.xml"/>
    </mappers>
</configuration>

　　

基于ssm逆向工程的使用

1、安装Mybatis generator插件

2、配置generatorConfig.xml

3、配置maven运行generator命令

4、在pom中处理generatorConfig.xml不能编译问题

 

generatorConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
<generatorConfiguration>
    <!-- 引入配置文件 -->
    <properties resource="jdbc.properties"/>

    <!--指定数据库jdbc驱动jar包的位置-->
    <classPathEntry location="D:\initPath\mvn_repository\mysql\mysql-connector-java\5.1.44\mysql-connector-java-5.1.44.jar"/>

    <!-- 一个数据库一个context -->
    <context id="infoGuardian">
        <!-- 注释 -->
        <commentGenerator>
            <property name="suppressAllComments" value="true"/><!-- 是否取消注释 -->
            <property name="suppressDate" value="true"/> <!-- 是否生成注释代时间戳 -->
        </commentGenerator>

        <!-- jdbc连接 -->
        <jdbcConnection driverClass="${jdbc.driver}"
                        connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/>

        <!-- 类型转换 -->
        <javaTypeResolver>
            <!-- 是否使用bigDecimal， false可自动转化以下类型（Long, Integer, Short, etc.） -->
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>

        <!-- 01 指定javaBean生成的位置 -->
        <!-- targetPackage：指定生成的model生成所在的包名 -->
        <!-- targetProject：指定在该项目下所在的路径  -->
        <javaModelGenerator targetPackage="com.javaxl.model"
                            targetProject="src/main/java">
            <!-- 是否允许子包，即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
            <!-- 是否对model添加构造函数 -->
            <property name="constructorBased" value="true"/>
            <!-- 是否针对string类型的字段在set的时候进行trim调用 -->
            <property name="trimStrings" value="false"/>
            <!-- 建立的Model对象是否 不可改变  即生成的Model对象不会有 setter方法，只有构造方法 -->
            <property name="immutable" value="false"/>
        </javaModelGenerator>

        <!-- 02 指定sql映射文件生成的位置 -->
        <sqlMapGenerator targetPackage="com.javaxl.mapper"
                         targetProject="src/main/java">
            <!-- 是否允许子包，即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
        </sqlMapGenerator>

        <!-- 03 生成XxxMapper接口 -->
        <!-- type="ANNOTATEDMAPPER",生成Java Model 和基于注解的Mapper对象 -->
        <!-- type="MIXEDMAPPER",生成基于注解的Java Model 和相应的Mapper对象 -->
        <!-- type="XMLMAPPER",生成SQLMap XML文件和独立的Mapper接口 -->
        <javaClientGenerator targetPackage="com.javaxl.mapper"
                             targetProject="src/main/java" type="XMLMAPPER">
            <!-- 是否在当前路径下新加一层schema,false路径com.oop.eksp.user.model， true:com.oop.eksp.user.model.[schemaName] -->
            <property name="enableSubPackages" value="false"/>
        </javaClientGenerator>

        <!-- 配置表信息 -->
        <!-- schema即为数据库名 -->
        <!-- tableName为对应的数据库表 -->
        <!-- domainObjectName是要生成的实体类 -->
        <!-- enable*ByExample是否生成 example类 -->
        <!--<table schema="" tableName="t_book" domainObjectName="Book"-->
               <!--enableCountByExample="false" enableDeleteByExample="false"-->
               <!--enableSelectByExample="false" enableUpdateByExample="false">-->
            <!--<!– 忽略列，不生成bean 字段 –>-->
            <!--<!– <ignoreColumn column="FRED" /> –>-->
            <!--<!– 指定列的java数据类型 –>-->
            <!--<!– <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /> –>-->
        <!--</table>-->

        <table schema="" tableName="t_mvc_Book" domainObjectName="Book"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
            <!-- 忽略列，不生成bean 字段 -->
            <!-- <ignoreColumn column="FRED" /> -->
            <!-- 指定列的java数据类型 -->
            <!-- <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /> -->
        </table>

    </context>
</generatorConfiguration>

　　

 

 

 

Mybatis增删改查案例

SessionUtil.java

package com.lingerqi.util;

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

/**
 * @author xyls
 * @create  2019-10-16 17:04
 */
public class SessionUtil {
    private static SqlSessionFactory sessionFactory;
    private static ThreadLocal<SqlSession> threadLocal = new ThreadLocal<SqlSession>();
    static {
        sessionFactory = new SqlSessionFactoryBuilder().build(SessionUtil.class.getResourceAsStream("/mybatis.cfg.xml"));
    }

    public static SqlSession openSession() {
        SqlSession session = threadLocal.get();
        if (null == session) {
            session = sessionFactory.openSession();
            threadLocal.set(session);
        }
        return session;
    }

    public static void main(String[] args) {
        SqlSession session = openSession();
        System.out.println(session.getConnection());
        session.close();
//        System.out.println(session.getConnection());
    }
}

　　BookService.java

 

 

package com.lingerqi.service;

import com.lingerqi.model.Book;

/**
 * @author xyls
 * @create  2019-10-16 17:02
 */
public interface BookService {
    int deleteByPrimaryKey(Integer bid);

    int insert(Book record);

    int insertSelective(Book record);

    Book selectByPrimaryKey(Integer bid);

    int updateByPrimaryKeySelective(Book record);

    int updateByPrimaryKey(Book record);
}

　　BookServiceImpl.java

 

　　

package com.lingerqi.service;

import com.lingerqi.mapper.BookMapper;
import com.lingerqi.model.Book;

/**
 * @author xyls
 * @create  2019-10-16 17:04
 */
public class BookServiceImpl implements BookService {
    private BookMapper bookMapper;

    public BookMapper getBookMapper() {
        return bookMapper;
    }

    public void setBookMapper(BookMapper bookMapper) {
        this.bookMapper = bookMapper;
    }

    @Override
    public int deleteByPrimaryKey(Integer bid) {
        return bookMapper.deleteByPrimaryKey(bid);
    }

    @Override
    public int insert(Book record) {
        return bookMapper.insert(record);
    }

    @Override
    public int insertSelective(Book record) {
        return bookMapper.insertSelective(record);
    }

    @Override
    public Book selectByPrimaryKey(Integer bid) {
        return bookMapper.selectByPrimaryKey(bid);
    }

    @Override
    public int updateByPrimaryKeySelective(Book record) {
        return bookMapper.updateByPrimaryKeySelective(record);
    }

    @Override
    public int updateByPrimaryKey(Book record) {
        return bookMapper.updateByPrimaryKey(record);
    }
}

 

　　BookServiceImplTest.java

 

 

package com.lingerqi.service;

import com.lingerqi.mapper.BookMapper;
import com.lingerqi.model.Book;
import com.lingerqi.util.SessionUtil;
import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import static org.junit.Assert.*;

/**
 * @author xyls
 * @create  2019-10-16 17:18
 */
public class BookServiceTest {

    private BookService bookService;
    private SqlSession sqlSession;

    @Before
    public void setUp() throws Exception {
        BookServiceImpl bookService = new BookServiceImpl();
        sqlSession = SessionUtil.openSession();
        BookMapper mapper = sqlSession.getMapper(BookMapper.class);
        bookService.setBookMapper(mapper);
        this.bookService=bookService;
    }

    @Test
    public void insert() {
        Book Book = new Book();
        bookService.insert(Book);
    }

    @Test
    public void selectByPrimaryKey() {
//        this.bookService.deleteByPrimaryKey(1262);
        Book book=this.bookService.selectByPrimaryKey(19);
        System.out.println(book);
    }
    @After
    public void tearDown() throws Exception{
        sqlSession.commit();
        sqlSession.close();
    }
}

 

　　

 

<properties>

        <maven.compiler.source>1.8</maven.compiler.source>

        <maven.compiler.target>1.8</maven.compiler.target>

    </properties>

 

    <dependencies>

        <!-- ********************** junit单元测试依赖 ********************** -->

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.12</version>

            <scope>test</scope>

        </dependency>

 

        <!-- ********************** Java Servlet API  ********************** -->

        <dependency>

            <groupId>javax.servlet</groupId>

            <artifactId>javax.servlet-api</artifactId>

            <version>4.0.0</version>

            <scope>provided</scope>

        </dependency>

 

        <!-- ********************** Mybatis依赖 ********************** -->

        <dependency>

            <groupId>org.mybatis</groupId>

            <artifactId>mybatis</artifactId>

            <version>3.4.5</version>

        </dependency>

 

        <!-- ********************** Mysql JDBC驱动 ********************** -->

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>5.1.44</version>

        </dependency>

 

        <!-- **********************  日志配置  ********************** -->

        <!--记得修改mybatis.cfg.xml添加如下内容-->

        <!--<setting name="logImpl" value="LOG4J2"/>-->

        <!--核心log4j2jar包-->

        <dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-core</artifactId>

            <version>2.9.1</version>

        </dependency>

        <dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-api</artifactId>

            <version>2.9.1</version>

        </dependency>

        <!--web工程需要包含log4j-web，非web工程不需要-->

        <dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-web</artifactId>

            <version>2.9.1</version>

        </dependency>

</dependencies>

 

 

 <build>

        <resources>

            <!--解决mybatis-generator-maven-plugin运行时没有将XxxMapper.xml文件放入target文件夹的问题-->

            <resource>

                <directory>src/main/java</directory>

                <includes>

                    <include>**/*.xml</include>

                </includes>

            </resource>

            <!--解决mybatis-generator-maven-plugin运行时没有将jdbc.properites文件放入target文件夹的问题-->

            <resource>

                <directory>src/main/resources</directory>

                <includes>

                    <include>jdbc.properties</include>

                    <include>*.xml</include>

                </includes>

            </resource>

        </resources>

 

        <plugins>

            <plugin>

                <groupId>org.mybatis.generator</groupId>

                <artifactId>mybatis-generator-maven-plugin</artifactId>

                <version>1.3.2</version>

                <dependencies>

                    <!--使用Mybatis-generator插件不能使用太高版本的mysql驱动 -->

                    <dependency>

                        <groupId>mysql</groupId>

                        <artifactId>mysql-connector-java</artifactId>

                        <version>5.1.44</version>

                    </dependency>

                </dependencies>

                <configuration>

                    <overwrite>true</overwrite>

                </configuration>

            </plugin>

        </plugins>

 

    </build>