mybatis入门及配置文件模板

1. 建立mybatis项目步骤　　

   1. 添加依赖包  4个  数据库   Junit  mybatis   1.8jdk

   2. 编写pojo对象（domain）
      

   3. 编写核心配置文件(config.xml)

   4. 编写核心配置文件编写映射文件(sqlMapper.xml)

   5. 测试框架

   6. 

2. 　　具体实现

   1. 　添加依赖包  4个  数据库   Junit  mybatis   1.8jdk

      1. 　　在maven中创键项目,用maven管理jar包　

      2.         配置maven pom.xml文件,

      3. 
      4. 　pom.xml源码模板
         

      5. <?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>cn.kgc</groupId>
             <artifactId>mybatis03</artifactId>
             <version>1.0-SNAPSHOT</version>
         
             <properties>
                 <maven.coppiler.source>1.8</maven.coppiler.source>
                 <maven.coppiler.target>1.8</maven.coppiler.target>
             </properties>
         
             <dependencies>
                 <dependency>
                     <groupId>mysql</groupId>
                     <artifactId>mysql-connector-java</artifactId>
                     <version>5.1.6</version>
                 </dependency>
                 <dependency>
                     <groupId>junit</groupId>
                     <artifactId>junit</artifactId>
                     <version>4.12</version>
                 </dependency>
                 <dependency>
                     <groupId>org.mybatis</groupId>
                     <artifactId>mybatis</artifactId>
                     <version>3.4.5</version>
                 </dependency>
             </dependencies>
         
         
         </project>

   2. 编写pojo对象

      1. 　　编写与数据库表对应的实体类(在idea中可以直接生成)

      2. 　　

   3. 　　编写核心配置文件(config.xml)

      1. 

      2. <?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>
           <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="org/mybatis/example/BlogMapper.xml"/>
           </mappers>
         </configuration>

         　

   4. 　　编写核心配置文件的映射文件(sqlMapper.xml)

      1. 

      2. sqlMapper.xml模板

      3. <?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="org.mybatis.example.BlogMapper">
           <select id="selectBlog" resultType="Blog">
             select * from Blog where id = #{id}
           </select>
         </mapper>

   5. 　　测试框架

      1. 　　测试文件

      2. package cn.kgc;
         
         import cn.kgc.pojo.NewsDetail;
         import org.apache.ibatis.session.SqlSession;
         import org.apache.ibatis.session.SqlSessionFactory;
         import org.apache.ibatis.session.SqlSessionFactoryBuilder;
         import org.junit.Test;
         
         import java.io.InputStream;
         import java.util.List;
         
         /**
          * @author liyang
          * @create 2019/6/28 16:18
          */
         public class TestNewDetail {
             @Test
             public void test(){
                 InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("SqlMapConfig.xml");
                 SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
                 SqlSessionFactory build = sqlSessionFactoryBuilder.build(resourceAsStream);
                 SqlSession sqlSession = build.openSession();
                 List<Object> objects = sqlSession.selectList("cn.kgc.pojo.findAll");
                 for (Object o : objects) {
                     NewsDetail newsDetail = (NewsDetail)o;
                     System.out.println(newsDetail);
                 }
             }
         }