做了個(gè)mybatis的Demo，發(fā)現(xiàn)mybatis和我之前實(shí)習(xí)時(shí)用的EOS開發(fā)工具中的對(duì)數(shù)據(jù)庫操作的組件很類似，現(xiàn)在想來那個(gè)EOS就是對(duì)mybatis進(jìn)行了封裝。

eclipse下的Demo

數(shù)據(jù)庫表

與數(shù)據(jù)表映射的實(shí)體類

//與數(shù)據(jù)表映射的實(shí)體類
package dao;

public class User {
    private int id;
    private String name;
    private int age;
    
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
     
    @Override
    public String toString() {
       return "User [id=" + id + ", name=" + name + ", age=" + age + "]";
    }
}

userMapper.xml

<!--userMapper.xml-->

<?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="mapping.userMapper">
     <!-- parameterType為傳入?yún)?shù)類型，resultType為結(jié)果返回接收的類型 -->
     <select id="getUser" parameterType="int" 
         resultType="dao.User">
         select * from users
     </select>
     
 </mapper>

mybatis配置文件

<!--  mybatis配置文件 -->

<?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" />
            <!-- 配置數(shù)據(jù)庫連接信息 -->
             <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver" />
                <property name="url" value="jdbc:mysql://localhost:3306/mybatis" />
                <property name="username" value="root" />
                <property name="password" value="000000" />
            </dataSource>
        </environment>
    </environments>
   
    <mappers>
        <!-- 注冊(cè)u(píng)serMapper.xml文件 -->
        <mapper resource="mapping/userMapper.xml"/>
    </mappers>
    
</configuration>

測(cè)試類

public class Test {

     public static void main(String[] args) {
        // TODO Auto-generated method stub
      //mybatis的配置文件
        String resource = "conf.xml";
        //使用類加載器加載mybatis的配置文件（它也加載關(guān)聯(lián)的映射文件）
        InputStream is = Test.class.getClassLoader().getResourceAsStream(resource);
        //構(gòu)建sqlSession的工廠
        SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(is);
        //使用MyBatis提供的Resources類加載mybatis的配置文件（它也加載關(guān)聯(lián)的映射文件）
        //Reader reader = Resources.getResourceAsReader(resource); 
        //構(gòu)建sqlSession的工廠
        //SqlSessionFactory sessionFactory = new SqlSessionFactoryBuilder().build(reader);
        //創(chuàng)建能執(zhí)行映射文件中sql的sqlSession
        
        SqlSession session = sessionFactory.openSession();

        String statement = "mapping.userMapper.getUser";//映射sql的標(biāo)識(shí)字符串

        List<User> userList = session.selectList(statement);
        
        for(int i = 0;i<userList.size();i++){
            System.out.println(userList.get(i).toString());

        }
    }
}

以上輸出結(jié)果是user表的所有內(nèi)容。

mapper.xml的sql語句中可以隨意的設(shè)置parameterType傳入?yún)?shù)，是基本類型也可以是自定義的類，查詢結(jié)果接收類型resultType也可以隨便設(shè)置只要sql查詢出的結(jié)果的屬性能夠滿足是resultType屬性的子集就可以（sql結(jié)果的屬性name在resultType中都能有與之相對(duì)應(yīng)的name）。

//mapper中設(shè)置
 <mapper namespace="mapping.userMapper">

     <select id="getUser" parameterType="dao.User" 
         resultType="dao.User">
         select * from users where id=#{id} and name = #{name}
     </select>
     
 </mapper>





//java中調(diào)用
        User user = new User();
        user.setAge(1);
        user.setId(1);
        user.setName("johnny");
//        HashMap<String, Object> map = new HashMap<String, Object>();
//        map.put("id", 2);
//        map.put("name", "asd");
        List<User> userList = session.selectList(statement, user);
        
        for(int i = 0;i<userList.size();i++){
            System.out.println(userList.get(i).toString());

        }