mybatis

mybatis类似hibernate，web数据库架构

需要的jar包
log4j-1.2.17.jar
mybatis-3.4.5.jar
mysql-connector-java-5.0.8-bin.jar

mybatis jar包下载地址：
https://github.com/mybatis/mybatis-3/releases

建立web项目MyBatis
src
mybatis.cfg.xml
mysql.properties
com.cy.mybatis.beans
UserBean.java
com.cy.mybatis.mapper
UserMapper.java
UserMapper.xml
com.cy.mybatis.service
UserService.java
com.cy.mybatis.tools
DBTools.java

package com.cy.mybatis.beans;

import java.io.Serializable;

public class UserBean implements Serializable{

    private static final long serialVersionUID = 1L;
    private Integer id;
    private String username;
    private String password;
    private Double account;
    
    public UserBean() {
        super();
    }
    
    public UserBean(String username, String password, Double account) {
        super();
        this.username = username;
        this.password = password;
        this.account = account;
    }

    public UserBean(Integer id, String username, String password, Double account) {
        super();
        this.id = id;
        this.username = username;
        this.password = password;
        this.account = account;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer 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;
    }

    public Double getAccount() {
        return account;
    }

    public void setAccount(Double account) {
        this.account = account;
    }

    @Override
    public String toString() {
        return "UserBean [id=" + id + ", username=" + username + ", password="
                + password + ", account=" + account + "]";
    }
}

mysql.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/mybatis
jdbc.username=root
jdbc.password=123456

UserMapper.java

package com.cy.mybatis.mapper;

import java.util.List;

import com.cy.mybatis.beans.UserBean;

public interface UserMapper {

    public int insertUser(UserBean user) throws Exception;

    public int updateUser (UserBean user,int id) throws Exception;

    public int deleteUser(int id) throws Exception;

    public UserBean selectUserById(int id) throws Exception;

    public List<UserBean> selectAllUser() throws Exception;
}

UserMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cy.mybatis.mapper.UserMapper">
<!-- 自定义返回结果集 -->
   <resultMap id="userMap" type="UserBean">
        <id property="id" column="id" javaType="java.lang.Integer"></id>
        <result property="username" column="username" javaType="java.lang.String"></result>
        <result property="password" column="password" javaType="java.lang.String"></result>
        <result property="account" column="account" javaType="java.lang.Double"></result>
    </resultMap>
<!-- 在各种标签中的id属性必须和接口中的方法名相同 ， id属性值必须是唯一的，不能够重复使用。parameterType属性指明查询时使用的参数类型，resultType属性指明查询返回的结果集类型-->    
<!-- useGeneratedKeys：（ 仅 对 insert 有 用 ） 这 会 告 诉 MyBatis 使 用 JDBC 的getGeneratedKeys 
            方法来取出由数据（比如：像 MySQL 和 SQLServer 这样的数据库管理系统的自动递增字段）内部生成的主键。默认值： false。 -->    
<!--keyProperty： （仅对 insert有用）标记一个属性， MyBatis 会通过 getGeneratedKeys或者通过 insert 语句的 selectKey 子元素设置它的值。默认：不设置。 -->
<!--#{}中的内容，为占位符，当参数为某个JavaBean时，表示放置该Bean对象的属性值  -->


    <insert id="insertUser" useGeneratedKeys="true" keyProperty="id">
        insert into t_user (username,password,account) values (#{username},#{password},#{account})
    </insert>
    
    <update id="updateUser" >
      update t_user set username=#{username},password=#{password},account=#{account} where id=#{id}
    </update>
    
    <delete id="deleteUser" parameterType="int">
     delete from t_user where id=#{id}  
    </delete>
    
    <select id="selectUserById" parameterType="int" resultMap="userMap">
     select * from t_user where id=#{id}
    </select>
    
    <select id="selectAllUser" resultMap="userMap">
     select * from t_user
    </select>  
</mapper>

UserService.java

package com.cy.mybatis.service;

import java.util.List;

import org.apache.ibatis.session.SqlSession;

import com.cy.mybatis.beans.UserBean;
import com.cy.mybatis.tools.DBTools;
import com.cy.mybatis.mapper.UserMapper;

public class UserService {

    public static void main(String[] args) {
        insertUser();
        // deleteUser();
        // selectUserById();
        // selectAllUser();
    }

    private static void insertUser() {
        SqlSession session = DBTools.getSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        UserBean user = new UserBean("muhe11", "123456", 7000.0);
        try {
            mapper.insertUser(user);
            System.out.println(user.toString());
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            session.rollback();
        }
    }

    private static void deleteUser() {
        SqlSession session = DBTools.getSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        try {
            mapper.deleteUser(1);
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            session.rollback();
        }
    }

    private static void selectUserById() {
        SqlSession session = DBTools.getSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        try {
            UserBean user = mapper.selectUserById(2);
            System.out.println(user.toString());

            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            session.rollback();
        }
    }

    private static void selectAllUser() {
        SqlSession session = DBTools.getSession();
        UserMapper mapper = session.getMapper(UserMapper.class);
        try {
            List<UserBean> user = mapper.selectAllUser();
            System.out.println(user.toString());
            session.commit();
        } catch (Exception e) {
            e.printStackTrace();
            session.rollback();
        }
    }
}

mybatis.cfg.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>

  <!-- 引入外部配置文件 -->
  <properties resource="mysql.properties"></properties>
  
  
   <!-- 为JAVA Bean起类别名 -->
   <typeAliases >
        <!-- 别名方式1，一个一个的配置 type中放置的是类的全路径，alias中放置的是类别名
        <typeAliase type="com.cy.mybatis.beans.UserBean" alias="UserBean"/> -->
        <!-- 别名方式2，自动扫描，将JAVA类的类名作为类的类别名 -->
        <package name="com.cy.mybatis.beans"/>
   </typeAliases>
   
   
   <!-- 配置mybatis运行环境 -->
     <environments default="cybatis">
        <environment id="cybatis">
            <!-- type="JDBC" 代表使用JDBC的提交和回滚来管理事务 -->
            <transactionManager type="JDBC" />
            
            <!-- mybatis提供了3种数据源类型，分别是：POOLED,UNPOOLED,JNDI -->
            <!-- POOLED 表示支持JDBC数据源连接池 -->
            <!-- UNPOOLED 表示不支持数据源连接池 -->
            <!-- JNDI 表示支持外部数据源连接池 -->
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
    </environments> 
    
    
    <mappers>
        <!-- 告知映射文件方式1，一个一个的配置
        <mapper resource="com/cy/mybatis/mapper/UserMapper.xml"/>-->
        <!-- 告知映射文件方式2，自动扫描包内的Mapper接口与配置文件 -->
        <package name="com/cy/mybatis/mapper"/>
    </mappers>
</configuration>

DBTools.java

package com.cy.mybatis.tools;

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;

public class DBTools {
    public static SqlSessionFactory sessionFactory;
    
    static{
        try {
            //使用MyBatis提供的Resources类加载mybatis的配置文件
            Reader reader = Resources.getResourceAsReader("mybatis.cfg.xml");
            //构建sqlSession的工厂
            sessionFactory = new SqlSessionFactoryBuilder().build(reader);
        } catch (Exception e) {
            e.printStackTrace();
        }
        
    }
    //创建能执行映射文件中sql的sqlSession
    public static SqlSession getSession(){
        return sessionFactory.openSession();
    }
    
}

创建数据库

mysql> create database mybatis;
mysql> use mybatis;
CREATE TABLE `t_user` (
`id` int(11) NOT NULL auto_increment,
`username` varchar(20) default NULL,
`password` varchar(20) default NULL,
`account` double(10,2) default NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=7 DEFAULT CHARSET=utf8

选中UserService.java，右键=>Run as =>Java Application
执行成功就会显示
UserBean [id=9, username=muhe, password=123456, account=7000.0]

posted @ 2018-02-26 10:32 牧天阅读(129) 评论(0) 收藏举报

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