欢迎您访问新疆栾骏商贸有限公司,公司主营电子五金轴承产品批发业务!
全国咨询热线: 400-8878-609

新闻资讯

常见问题

JAVA MyBatis入门学习过程记录

作者:用户投稿2026-01-11 02:41:44
目录
  • 一、Mybatis
    • 1、mybatis-config.xml
    • 2、Mapper.xml
    • 3、db.properties
    • 4、MybatisUtils工具类
    • 5、多对一AND多对一:
    • 6、使用注解开发
    • 7、自定义缓存:ehcache
    • 8、mybatis 其他工具
  • 二、MAVEN资源导出错误解决
    • 三、常用依赖导入
      • 四、LOG4J
        • 1、log4j.properties 配置文件
        • 2、log4j 在mybatis-config.xml的配置
        • 3、使用场景
      • 好用的插件:
        • 1、lombok
      • 总结

        一、Mybatis

        1、mybatis-config.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>
        <!--    外部引入db-->
            <properties resource="db.properties"/>
            <settings>
        <!--        配置日志文件-->
        <!--        <setting name="logImpl" value="STDOUT_LOGGING"/>-->
                <setting name="logImpl" value="log4j"/>
        <!--        开启A_NAME==>aName-->        
                <setting name="mapUnderscoreToCamelCase" valie="true"
            </settings>
        <!--   减少类型-->
            <typeAliases>        <typeAlias type="com.wang.pojo.User" alias="User"/>
            </typeAliases>
            <environments default="development">
                <environment id="development">
                    <transactionManager type="JDBC"/>
                    <dataSource type="POOLED">
                        <property name="driver" value="${driver}"/>
                        <property name="url" value="${url}"/>
                        <property name="username" value="${username}"/>
                        <property name="password" value="${password}"/>
                    </dataSource>
                </environment>
            </environments>
            <mappers>
                <mapper resource="com/wang/dao/UserMapper.xml"/>
            </mappers>
        </configuration>
        

        2、Mapper.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.wang.dao.UserDao">
            <select id="getUserList" resultType="User">
                select * from mybatis.user
            </select>
        </mapper>
        

        3、db.properties

        driver=com.mysql.jdbc.Driver
        url=jdbc:mysql://localhost:3306/mybatis
        username=root
        password=123456
        

        4、MybatisUtils工具类

        package com.wang.utils;
        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 MybatisUtils {
            private static SqlSessionFactory sqlSessionFactory;
            static {
                InputStream inputStream = null;
                try {
                    String resource = "mybatis-config.xml";
                    inputStream = Resources.getResourceAsStream(resource);
                    sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            public static SqlSession getsqlsession() {
                return sqlSessionFactory.openSession();
            }
        }
        

        5、多对一AND多对一:

        在Mapper.xml中配置

        association 对象 多对一

        collection 集合 一对多

        从用参数解释:

        •  javaType java类型
        • ofType 泛型约束类型

        6、使用注解开发

        可在接口中使用注解进行开发,省去Mapper.xml

        @Select("select * from mybatis.User")
        List<User> getUserList();
        在mybatis-config.xml中配置
        <mappers>
                <mapper class="com.wang.Dao.UserMapper"
        </mappers>

        7、自定义缓存:ehcache

        8、mybatis 其他工具

        mybatis Hepler:https://pagehelper.github.io/

        二、MAVEN资源导出错误解决

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

        三、常用依赖导入

            <!--导入依赖-->
            <dependencies>
                <!--    mysql-->
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>5.1.49</version>
                </dependency>
                <!--        mybatis-->
                <dependency>
                    <groupId>org.mybatis</groupId>
                    <artifactId>mybatis</artifactId>
                    <version>3.5.2</version>
                </dependency>
                <!--        junit-->
                <dependency>
                    <groupId>junit</groupId>
                    <artifactId>junit</artifactId>
                    <version>4.13</version>
                </dependency>
        <!--        lombok-->
                <dependency>
                    <groupId>org.projectlombok</groupId>
                    <artifactId>lombok</artifactId>
                    <version>1.18.20</version>
                </dependency>
        <!--        servlet and jsp-->
                <dependency>
                    <groupId>org.mortbay.jetty</groupId>
                    <artifactId>servlet-api-2.5</artifactId>
                    <version>6.1.7</version>
                </dependency>
                <dependency>
                    <groupId>javax.servlet.jsp</groupId>
                    <artifactId>jsp-api</artifactId>
                    <version>2.1</version>
                </dependency>
        <!--        standard-->     
                <dependency>
                    <groupId>org.apache.karaf.assemblies.features</groupId>
                    <artifactId>standard</artifactId>
                    <version>2.4.4</version>
                </dependency>
                <dependency>
                    <groupId>taglibs</groupId>
                    <artifactId>standard</artifactId>
                    <version>1.1.2</version>
                </dependency>
        <!--        jstl-->       
                <dependency>
                    <groupId>javax.servlet.jsp.jstl</groupId>
                    <artifactId>jstl-api</artifactId>
                    <version>1.2</version>
                </dependency>
                <dependency>
                    <groupId>org.glassfish.web</groupId>
                    <artifactId>jstl-impl</artifactId>
                    <version>1.2</version>
                </dependency>
         <!--        fastjson-->    
                <dependency>
                    <groupId>com.alibaba</groupId>
                    <artifactId>fastjson</artifactId>
                    <version>1.2.76</version>
                </dependency>
                <!--Log4j-->
                <dependency>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                    <version>1.2.17</version>
                </dependency>
            </dependencies>
        

        四、LOG4J

        1、log4j.properties 配置文件

            <!--导入依赖-->
            <dependencies>
                <!--    mysql-->
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>5.1.49</version>
                </dependency>
                <!--        mybatis-->
                <dependency>
                    <groupId>org.mybatis</groupId>
                    <artifactId>mybatis</artifactId>
                    <version>3.5.2</version>
                </dependency>
                <!--        junit-->
                <dependency>
                    <groupId>junit</groupId>
                    <artifactId>junit</artifactId>
                    <version>4.13</version>
                </dependency>
        <!--        lombok-->
                <dependency>
                    <groupId>org.projectlombok</groupId>
                    <artifactId>lombok</artifactId>
                    <version>1.18.20</version>
                </dependency>
        <!--        servlet and jsp-->
                <dependency>
                    <groupId>org.mortbay.jetty</groupId>
                    <artifactId>servlet-api-2.5</artifactId>
                    <version>6.1.7</version>
                </dependency>
                <dependency>
                    <groupId>javax.servlet.jsp</groupId>
                    <artifactId>jsp-api</artifactId>
                    <version>2.1</version>
                </dependency>
        <!--        standard-->     
                <dependency>
                    <groupId>org.apache.karaf.assemblies.features</groupId>
                    <artifactId>standard</artifactId>
                    <version>2.4.4</version>
                </dependency>
                <dependency>
                    <groupId>taglibs</groupId>
                    <artifactId>standard</artifactId>
                    <version>1.1.2</version>
                </dependency>
        <!--        jstl-->       
                <dependency>
                    <groupId>javax.servlet.jsp.jstl</groupId>
                    <artifactId>jstl-api</artifactId>
                    <version>1.2</version>
                </dependency>
                <dependency>
                    <groupId>org.glassfish.web</groupId>
                    <artifactId>jstl-impl</artifactId>
                    <version>1.2</version>
                </dependency>
         <!--        fastjson-->    
                <dependency>
                    <groupId>com.alibaba</groupId>
                    <artifactId>fastjson</artifactId>
                    <version>1.2.76</version>
                </dependency>
                <!--Log4j-->
                <dependency>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                    <version>1.2.17</version>
                </dependency>
            </dependencies>
        

        2、log4j 在mybatis-config.xml的配置

        <settings>
                <setting name="logImpl" value="LOG4J"/>
        </settings>
        

        3、使用场景

        在具体类中引入

        Logger logger = Logger.getLogger(UserDaoTest.class);
        logger.error();
        logger.debug();
        

        好用的插件:

        1、lombok

        常用注解:

        • @Data 自动生成geter seter
        • @AllArgsConstructor 生成有参构造函数
        • @NoArgsConstructor 生成无参构造函数

        =“logImpl” value=“LOG4J”/>

        ## 3、使用场景
        
        - 在具体类中引入
        
          ```java
          Logger logger = Logger.getLogger(UserDaoTest.class);
          logger.error();
          logger.debug();
        

        常用注解:

        • @Data 自动生成geter seter
        • @AllArgsConstructor 生成有参构造函数
        • @NoArgsConstructor 生成无参构造函数

        总结

        本篇文章就到这里了,希望能够给大家带来帮助,也希望您能够能够多多关注的更多内容!