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", 1);
        System.out.println(temp.getUserName());
        session.close();
    }

}

最后运行项目：

得到了数据库中的数据