入门的配置和使用

依赖的环境

1. jar包 mybatis 3.3.0 和 mysql-connector-java 5.1.37

   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis</artifactId>
       <version>3.3.0</version>
   </dependency>
       <dependency>
   <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
       <version>5.1.37</version>
   </dependency>
   

   1. 数据库，使用的是mysql

      创建数据库(mybatis20151125)
      创建表 user

      Create TABLE user ( id int(11) NOT NULL AUTO_INCREMENT, userName varchar(50) DEFAULT NULL, userAge int(11) DEFAULT NULL, userAddress varchar(200) DEFAULT NULL, PRIMARY KEY (id) ) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8; > 插入数据

      insert into user VALUES ('1', '111', '111', 'beijing');

创建的是一个Maven项目（Java工程）

• 项目结构图:

• 项目文件的内容

• Configuration.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>
  
          <!--类的别名-->
          <typeAliases> 
              <typeAlias alias="User" type="com.sun.useMyBatis3.useMyBatis3.model.User"/> 
          </typeAliases>
  
          <!-- 数据库连接信息 -->
          <environments default="development">
              <environment id="development">
              <transactionManager type="JDBC"/>
                  <dataSource type="POOLED">
                  <property name="driver" value="com.mysql.jdbc.Driver"/>
                  <property name="url" value="jdbc:mysql://127.0.0.1:3306/mybatis20151125"/>
                  <property name="username" value="root"/>
                  <property name="password" value="000000"/>
                  </dataSource>
              </environment>
          </environments>
  
          <!-- 对应的Mapper -->
          <mappers>
              <mapper resource="com/sun/useMyBatis3/useMyBatis3/model/User.xml"/>
          </mappers>
      </configuration>
  

• User.java

      package com.sun.useMyBatis3.useMyBatis3.model;          
      public class User {
  
          private String id;
          private String userName;
          private String userAge;
          private String address;
  
          public String getId() {
              return id;
          }
          public void setId(String id) {
              this.id = id;
          }
          public String getUserName() {
              return userName;
          }
          public void setUserName(String userName) {
              this.userName = userName;
          }
          public String getUserAge() {
              return userAge;
          }
          public void setUserAge(String userAge) {
              this.userAge = userAge;
          }
          public String getAddress() {
              return address;
          }
          public void setAddress(String address) {
              this.address = address;
          }
      }
  

• User.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="com.sun.useMyBatis3.useMyBatis3.model.UserMapper">
          <select id="selectUserByID" parameterType="int" resultType="User">
              select * from `user` where id = #{id}
          </select>
      </mapper>
  

  • UserTest.java

    package com.sun.useMyBatis3.useMyBatis3.test;
    
    import java.io.Reader;
    
    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 com.sun.useMyBatis3.useMyBatis3.model.User;
    
    public class UserTest {
    
        private static SqlSessionFactory sqlSessionFactory;
        private static Reader reader;
    
        static {
            try{
                //
                reader = Resources.getResourceAsReader("Configuration.xml");
                sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
        public static SqlSessionFactory getSqlSessionFactory(){
            return sqlSessionFactory;
        }
    
        public static void main(String [] args) {
            SqlSession sqlSession = getSqlSessionFactory().openSession();
            try{
                User user = (User) sqlSession.selectOne("com.sun.useMyBatis3.useMyBatis3.model.UserMapper.selectUserByID",1);
                System.out.println(user.getId());
                System.out.println(user.getUserName());
                System.out.println(user.getUserAge());
                System.out.println(user.getAddress());          
            } finally{
                sqlSession.close();
            }
        }
    }
    

以接口的方式配置

• 接口类 UserImpl.java

  package com.sun.useMyBatis3.useMyBatis3.model.impl;
  
  import com.sun.useMyBatis3.useMyBatis3.model.User;
  /**
   * 以接口的方式调用
   * 2015年11月25日 下午10:55:51
   *
   */
  public interface UserImpl {
  
      public User selectUserByID(int id);
  
  }
  

• User.xml namespace后面的内容要对应自己的接口

  <?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">
  
  <!--namespace和id确定了要执行的sql-->
  <mapper namespace="com.sun.useMyBatis3.useMyBatis3.model.impl.UserImpl">
      <select id="selectUserByID" parameterType="int" resultType="User">
          select * from `user` where id = #{id}
      </select>
  </mapper>
  

  • 测试类(UserTest.java)

    package com.sun.useMyBatis3.useMyBatis3.test;

    import java.io.Reader;

    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 com.sun.useMyBatis3.useMyBatis3.model.User; import com.sun.useMyBatis3.useMyBatis3.model.impl.UserImpl;

    /* * 测试MyBatis * 2015年11月25日 下午10:11:47 * @author * /

    public class UserTest {

    private static SqlSessionFactory sqlSessionFactory;
    private static Reader reader;
    
    static {
        try{
            //
            reader = Resources.getResourceAsReader("Configuration.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    public static SqlSessionFactory getSqlSessionFactory(){
        return sqlSessionFactory;
    }
    
    public static void main(String [] args) {
        SqlSession sqlSession = getSqlSessionFactory().openSession();
        try{            
            UserImpl userImpl = sqlSession.getMapper(UserImpl.class);
            User user1 = userImpl.selectUserByID(1);
            System.out.println(user1.getAddress());
            System.out.println(user1.getUserName());
        } finally {
            sqlSession.close();
        }
    }
    

    }