mybatis hellworld

用maven来进行搭建项目的~~

 

1. 搭建环境 pom.xml

1. <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.jamkong</groupId>
       <artifactId>simpleMybatis</artifactId>
       <version>0.0.1-SNAPSHOT</version>
       <packaging>jar</packaging>
       <name>simpleMybatis</name>
       <url>http://maven.apache.org</url>
       <properties>
           <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
       </properties>
       <dependencies>
           <dependency>
               <groupId>junit</groupId>
               <artifactId>junit</artifactId>
               <version>3.8.1</version>
               <scope>test</scope>
           </dependency>
           <dependency>
               <groupId>mysql</groupId>
               <artifactId>mysql-connector-java</artifactId>
               <version>5.1.34</version>
           </dependency>
           <dependency>
               <groupId>org.mybatis</groupId>
               <artifactId>mybatis</artifactId>
               <version>3.3.0</version>
           </dependency>
       </dependencies>
   </project>

2. 创建数据库 test

test数据库中的 user 表

3. 创建实体User

1. public class User {
       private int id;
       private String name;
       private String age;
       private String address;
       //省略get set方法
   }

4. 创建Dao接口 UserDao

1. public interface UserDao {
       //查询所有User
       public List<User> list();
   }

5. 进入主题：配置mybatis的配置文件：configuration.xml （名字可以随意）

1.  <?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>
        <!-- 对实体类进行设置别名，别名主要是用于映射文件上的，可以看UserDao.xml文件的resultType的值，该值就是用到这里的别名 -->
        <typeAliases>
            <typeAlias alias="User" type="cn.jamkong.mybatisDemo.domain.User"/>
        </typeAliases>
        <!-- 配置环境 -->
        <environments default="mysql">
            <environment id="mysql">
                <!-- 使用JDBC来管理事务 -->
                <transactionManager type="JDBC"/>
                <!-- 设置数据源 -->
                <dataSource type="POOLED">
                    <property name="driver" value="com.mysql.jdbc.Driver"/>
                    <property name="url" value="jdbc:mysql://localhost:3306/test"/>
                    <property name="username" value="root"/>
                    <property name="password" value="root"/>
                </dataSource>
            </environment>
        </environments>
        <!-- 映射文件 -->
        <mappers>
            <mapper resource="mapping/UserDao.xml"/>
        </mappers>
    </configuration>

6. 写Dao的映射文件：如UserDao.xml

1.  <?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="cn.jamkong.mybatisDemo.dao.UserDao">
        <resultMap type="User" id="userMap">
            <id property="id" column="id"/>
            <result property="name" column="name"/>
            <result property="age" column="age"/>
            <result property="address" column="address"/>
        </resultMap>
   
        <select id="list" resultType="User" resultMap="userMap">
            <![CDATA[
                SELECT * FROM `USER`
            ]]>
        </select>
    </mapper>

7. 现在已经都搭建好了，准备测试：

package mybatisDemo;
import java.io.IOException;
import java.io.Reader;
import java.util.List;
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 org.junit.Test;
import cn.jamkong.mybatisDemo.domain.User;
/**
 * 测试类
 *
 * @author Administrator
 *
 */
public class Test1 {
    private static SqlSessionFactory sqlSessionFactory;
    private static Reader reader;
    static {
        try {
            reader = Resources.getResourceAsReader("configuration.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SqlSession getSession() {
        return sqlSessionFactory.openSession();
    }
    @Test
    public void test() {
        SqlSession session = getSession();
        List<User> list = session.selectList("cn.jamkong.mybatisDemo.dao.UserDao.list");
        for (int i = 0; i < list.size(); i++) {
            System.out.println("id:" + list.get(i).getId() + " name:" + list.get(i).getName() + " age:"
                    + list.get(i).getAge() + " address:" + list.get(i).getAddress());
        }
    }
}

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