mybatis hellworld

用maven来进行搭建项目的~~

1. 搭建环境 pom.xml

<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

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

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"?>
 2 <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
 3 "http://mybatis.org/dtd/mybatis-3-config.dtd">
 4 <configuration>
 5     <!-- 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 -->
 6     <typeAliases>
 7         <typeAlias alias="User" type="cn.jamkong.mybatisDemo.domain.User"/>
 8     </typeAliases>
 9     <!-- 配置环境 -->
10     <environments default="mysql">
11         <environment id="mysql">
12             <!-- 使用JDBC来管理事务 -->
13             <transactionManager type="JDBC"/>
14             <!-- 设置数据源 -->
15             <dataSource type="POOLED">
16                 <property name="driver" value="com.mysql.jdbc.Driver"/>
17                 <property name="url" value="jdbc:mysql://localhost:3306/test"/>
18                 <property name="username" value="root"/>
19                 <property name="password" value="root"/>
20             </dataSource>
21         </environment>
22     </environments>
23     <!-- 映射文件 -->
24     <mappers>
25         <mapper resource="mapping/UserDao.xml"/>
26     </mappers>
27 </configuration>

6. 写Dao的映射文件：如UserDao.xml

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
 3 "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 4 <mapper namespace="cn.jamkong.mybatisDemo.dao.UserDao">
 5     <resultMap type="User" id="userMap">
 6         <id property="id" column="id"/>
 7         <result property="name" column="name"/>
 8         <result property="age" column="age"/>
 9         <result property="address" column="address"/>
10     </resultMap>
11     
12     <select id="list" resultType="User" resultMap="userMap">
13         <![CDATA[
14             SELECT * FROM `USER`
15         ]]>
16     </select>
17 </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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