一.mybatis入门及环境搭建:
目录
配置pom.xml文件
<?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.zking</groupId> <artifactId>mybatis1</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>mybatis1 Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <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> <finalName>mybatis1</finalName> <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> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <version>3.2.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </build> </project>
建立jdbc.properties连接数据库
jdbc.driver=com.mysql.jdbc.Driver jdbc.url=jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8 jdbc.username=mybatis_ssm jdbc.password=123456
配置web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <display-name>Archetype Created Web Application</display-name> </web-app>
安装插件
点击file选中settings 安装Free mybatis
安装Mybatis generator
安装mybatis tools
安装maven helper
配置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>
配置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="C:\\temp2\\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.zking.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.zking.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.zking.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>
二.mybatis的增删改查:
生成的代码
建立BookBiz
package com.zking.biz; import com.zking.model.Book; public interface BookBiz { int deleteByPrimaryKey(Integer bid); int insert(Book record); int insertSelective(Book record); Book selectByPrimaryKey(Integer bid); int updateByPrimaryKeySelective(Book record); int updateByPrimaryKey(Book record); }
建立BookBizimpl
package com.zking.biz.impl; import com.zking.biz.BookBiz; import com.zking.mapper.BookMapper; import com.zking.model.Book; /** * @author bing人 * @site * @company xy集团 * @create 2023-08-21 10:16 */ public class BookBizimpl implements BookBiz { private 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.updateByPrimaryKeySelective(record); } }
建立工具类SessionUtil
package com.zking.utils; import org.apache.ibatis.session.SqlSession; import org.apache.ibatis.session.SqlSessionFactory; import org.apache.ibatis.session.SqlSessionFactoryBuilder; /** * @author bing人 * @site www.javaxl.com * @company xy公司 * @create 2023-8-20 21:59 */ 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()); } }
编写demo
package com.zking.demo; import com.zking.biz.BookBiz; import com.zking.biz.impl.BookBizimpl; import com.zking.mapper.BookMapper; import com.zking.model.Book; import com.zking.utils.SessionUtil; import org.apache.ibatis.session.SqlSession; import org.junit.After; import org.junit.Before; import org.junit.Test; /** * @author bing人 * @site * @company xy集团 * @create 2023-08-21 10:28 */ public class Demo1 { private BookBiz bookBiz; private SqlSession sqlSession; @Before public void a(){ System.out.println("执行测试方法之前会执行的初始化代码块方法"); this.sqlSession = SessionUtil.openSession(); BookBizimpl book = new BookBizimpl(); BookMapper mapper = this.sqlSession.getMapper(BookMapper.class); book.setBookMapper(mapper); this.bookBiz = book; } @After public void b(){ System.out.println("执行测试方法之后的后执行的方法"); //提交事务 this.sqlSession.commit(); } @Test public void text1(){ System.out.println("测试查询方法方法.."); Book book = bookBiz.selectByPrimaryKey(25); System.out.println(book); } @Test public void text2(){ System.out.println("删除的方法"); int insert = bookBiz.deleteByPrimaryKey(30); } }
输出结果