目的：
mybatis简介
MyBatis 是一款优秀的持久层框架，它支持定制化 SQL、存储过程以及高级映射。
MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。
MyBatis 可以使用简单的 XML 或注解来配置和映射原生信息，将接口和 Java 的 POJOs(Plain Ordinary Java Object,普通的 Java对象)映射成数据库中的记录。
搭建mybatis环境
1、创建maven工程
2、导入相关pom依赖
3、Mybatis相关插件安装
Free mybatis plugin
Mybatis generater
mybatis tools
maven helper
4、Mybatis.cfg.xml配置
Pom.xml依赖
<?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/maven-v4_0_0.xsd">
<parent>
<artifactId>module</artifactId>
<groupId>com.huangting</groupId>
<version>1.0-SNAPSHOT</version>
</parent> <modelVersion>4.0.</modelVersion>
<packaging>war</packaging> <name>mybatis</name>
<artifactId>mybatis</artifactId>
<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.</version>
<scope>provided</scope>
</dependency> <!-- ********************** Mybatis依赖 ********************** -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.</version>
</dependency> <!-- ********************** Mysql JDBC驱动 ********************** -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.</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.</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.9.</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.</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</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>
<pluginManagement>
<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>
<groupId>org.mortbay.jetty</groupId>
<artifactId>maven-jetty-plugin</artifactId>
<version>6.1.7</version>
<configuration>
<connectors>
<connector implementation="org.mortbay.jetty.nio.SelectChannelConnector">
<port>8888</port>
<maxIdleTime>30000</maxIdleTime>
</connector>
</connectors>
<webAppSourceDirectory>${project.build.directory}/${pom.artifactId}-${pom.version}
</webAppSourceDirectory>
<contextPath>/</contextPath>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
Jdbc.properties 连接数据库配置文件
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/t224?useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=
接下来安装以下插件
Free mybatis plugin
Mybatis generater
mybatis tools
maven helper
mybatis.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 引入外部配置文件 -->
<properties resource="jdbc.properties"/> <settings>
<setting name="logImpl" value="LOG4J2"/>
</settings> <!-- 别名 -->
<typeAliases>
<!--<typeAlias type="com.huangting.model.Book" alias="Book"/>-->
</typeAliases> <!-- 配置mybatis运行环境 -->
<environments default="development">
<environment id="development">
<!-- type="JDBC" 代表使用JDBC的提交和回滚来管理事务 -->
<transactionManager type="jdbc"/> <!-- mybatis提供了3种数据源类型，分别是：POOLED,UNPOOLED,JNDI -->
<!-- POOLED 表示支持JDBC数据源连接池 -->
<!-- UNPOOLED 表示不支持数据源连接池 -->
<!-- JNDI 表示支持外部数据源连接池 -->
<dataSource type="POOLED">
<property name="driver"
value="${jdbc.driver}"/>
<property name="url"
value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments> <mappers>
<!--<mapper resource="com/haungting/mapper/BookMapper.xml"/>-->
</mappers>
</configuration>
基于ssm逆向工程的使用
配置generatorConfig.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
"http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
<generatorConfiguration>
<!-- 引入配置文件 -->
<properties resource="jdbc.properties"/> <!--指定数据库jdbc驱动jar包的位置-->
<classPathEntry location="E:\Maven\Maven_cang\mysql\mysql-connector-java\5.1.44\mysql-connector-java-5.1.44.jar"/> <!-- 一个数据库一个context -->
<context id="infoGuardian">
<!-- 注释 -->
<commentGenerator>
<property name="suppressAllComments" value="true"/><!-- 是否取消注释 -->
<property name="suppressDate" value="true"/> <!-- 是否生成注释代时间戳 -->
</commentGenerator> <!-- jdbc连接 -->
<jdbcConnection driverClass="${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.huangting.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.huangting.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.huangting.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>
配置maven运行generator命令
从这里面去配置maven
mybatis-generator:generate -e然后点击运行，自动生成文件
Mybatis增删改查案例
SessionUtil.java
package com.huangting.util;import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;/**
* @author 黄大娘
* @company dogson有限公司
* @create 2019-09-20 5:05
*/
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();//关闭session
// System.out.println(session.getConnection());
}
}
BookService.java
package com.huangting.service;import com.huangting.model.Book;/**
* @author 黄大娘
* @company dogson有限公司
* @create 2019-09-20 5:08
*/
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.huangting.service.ipml;import com.huangting.mapper.BookMapper;
import com.huangting.model.Book;
import com.huangting.service.Bookservice;/**
* @author 黄大娘
* @company dogson有限公司
* @create 2019-09-20 5:12
*/
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 0;
} @Override
public int updateByPrimaryKey(Book record) {
return 0;
}
}
BookServiceImplTest.java
package com.huangting.test;import com.huangting.mapper.BookMapper;
import com.huangting.model.Book;
import com.huangting.service.Bookservice;
import com.huangting.service.ipml.BookServiceImpl;
import com.huangting.util.SessionUtil;
import org.apache.ibatis.session.SqlSession;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;/**
* @author 黄大娘
* @company dogson有限公司
* @create 2019-09-20 5:14
*/
public class BookServiceImplTest {
private Bookservice bookService;
private SqlSession sqlSession; @Before
public void setUp() throws Exception {
BookServiceImpl bookServiceImpl = new BookServiceImpl();
sqlSession = SessionUtil.openSession();
bookServiceImpl.setBookMapper(sqlSession.getMapper(BookMapper.class));
this.bookService = bookServiceImpl;
} @After
public void tearDown() throws Exception {
sqlSession.commit();
sqlSession.close();
} @Test
public void insert() {
Book book = new Book();
book.setBname("zzz");
book.setPrice(12.3);
book.setBid(5);
int insert = bookService.insert(book);
} @Test
public void selectByPrimaryKey() {
Book book = this.bookService.selectByPrimaryKey(66);
System.out.println(book); }
}
效果：
查询
新增：
