MyBatis第一个项目示例

1、创建一个Java project，JikeBook

2、添加项目所需的依赖包

如 mybatis-3.2.8.jar,是实现mybatis功能所必需的依赖包

mysql-connector-java-3.0.17-ga-bin.jar是连接mysql数据库的依赖包，

log4j是日志输出依赖包

3、在src目录下创建各个package

4、首先创建log4j.properties

 log4j.rootLogger=DEBUG, Console  

 #Console
 log4j.appender.Console=org.apache.log4j.ConsoleAppender
 log4j.appender.Console.layout=org.apache.log4j.PatternLayout
 log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n  

 log4j.logger.java.sql.ResultSet=INFO
 log4j.logger.org.apache=INFO
 log4j.logger.java.sql.Connection=DEBUG
 log4j.logger.java.sql.Statement=DEBUG
 log4j.logger.java.sql.PreparedStatement=DEBUG

将一些日志的输出更改为DEBUG，才能输出相关日志信息

5、在jike.book.map包下创建jikeUser.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="/">

   <select id="findById"  parameterType="int"  resultType="jike.book.pojo.JiKeUser">
         select * from jikeUser where id=#{id}
   </select>

 </mapper>

6、在jike.book.map包下创建MyBatisConfig.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>

   <environments default="development">
      <environment id="development">
        <transactionManager type="JDBC">
        </transactionManager>
        <dataSource type="POOLED">
              <property name="driver" value="com.mysql.jdbc.Driver"/>
              <property name="url" value="jdbc:mysql://localhost:3306/jikebook"/>
              <property name="username" value="root"/>
              <property name="password" value=""/>
        </dataSource>
      </environment>
   </environments>

   <mappers>
         <mapper resource="jike/book/map/jikeUser.xml"/>
   </mappers>

 </configuration>

7、在jike.book.pojo下创建JiKeUser.java

 package jike.book.pojo;

 public class JiKeUser {
     private int id;
     private String userName;
     private String password;
     public int getId() {
         return id;
     }
     public void setId(int id) {
         this.id = id;
     }
     public String getUserName() {
         return userName;
     }
     public void setUserName(String userName) {
         this.userName = userName;
     }
     public String getPassword() {
         return password;
     }
     public void setPassword(String password) {
         this.password = password;
     }
 }

8、在jike.book.test下创建TestHello.java

 package jike.book.test;

 import java.io.IOException;
 import java.io.Reader;

 import jike.book.pojo.JiKeUser;

 import org.apache.ibatis.io.Resources;
 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;

 public class TestHello {

     public static void main(String[] args) {

         String resource = "jike/book/map/MyBatisConfig.xml";
         Reader reader = null;
         SqlSession session;
         try {
             reader = Resources.getResourceAsReader(resource);
         } catch (IOException e) {
             e.printStackTrace();
         }
         SqlSessionFactory sqlMapper = new SqlSessionFactoryBuilder()
                 .build(reader);
         session = sqlMapper.openSession();
         JiKeUser temp = session.selectOne("findById", );
         System.out.println(temp.getUserName());
         session.close();
     }

 }

最后运行项目：

得到了数据库中的数据